SOIL SURVEY of WHITMAN COUNTY, WASHINGTON by Norman C

This is a scanned version of the text of the original Soil Survey report of Whitman County, Washington issued April 1980. Original tables and maps were deleted. There may be references in the text that refer to a table that is not in this document.

Updated tables were generated from the NRCS National Soil Information System (NASIS). The soil map data has been digitized and may include some updated information. These are available from http://soildatamart.nrcs.usda.gov

Please contact the State Soil Scientist, Natural Resources Conservation Service (formerly Soil Conservation Service) for additional information.

SOIL SURVEY OF WHITMAN COUNTY, WASHINGTON By Norman C. Donaldson, Soil Conservation Service Fieldwork by Norman C. Donaldson, Herman R. Gentry, Eveard T. Harrison, Jesse J. Newlun, Dale D. Stockman, Alfonso DeBose, and George W. Hartman' United States Department of Agriculture, Soil Conservation Service, in cooperation with Washington State University Agricultural Research Center

WHITMAN COUNTY is in the southeastern part of How This Survey Was Made Washington (fig. 1). It has an area of 1,385,370 acres. Soil scientists made this survey to learn what kinds Most of the county has a rolling to hilly topography of soil are in Whitman County, where they are located, and deep soils that formed in silty material deposited and how they can be used. The soil scientists went into by wind. Basalt is the base rock, but there are a few the county knowing they likely would find many soils promontories of quartzite, shale, and sandstone. they had already seen, and perhaps some they had not. Elevation is about 4,000 feet in Tekoa Mountain, the They observed the steepness, length, and shape of highest part of the county. slopes; the size and speed of streams; the kinds of Channeled scablands (3) in the western part of the native plants or crops; the kinds of rock; and many county consist of a broad basalt plateau that was facts about the soils. They dug many holes to expose stripped of soil by glacial floodwaters. Many islandlike soil profiles. A profile is the sequence of natural layers, or remnants of preglacial soils remained after the glacial horizons, in a soil. It extends from the surface down into floods. Channels that run in a southwest direction were the parent material that has not been changed much by cut in the basalt bedrock. Some are now occupied by leaching or by the action of plant roots. potholes and lakes. Bonnie and Rock Lakes are in this The soil scientists made comparisons among the area. profiles they studied, and they compared these profiles Most of the survey area drains into the Palouse River with those in nearby counties and in more distant and its tributaries. The Palouse River heads in the places. They classified and named the soils according to mountains of Idaho adjacent to the eastern boundary of nationwide, uniform procedures. the county, and the north and south forks of the river Soils that have similar profiles make up a soil series. converge near the center of the county at Colfax. It Except for different texture in the surface layer, all flows west and south from Colfax to its junction with the Snake River at the extreme southwest corner of the survey area. Principal tributaries of the Palouse River include Rock, Pine, and Cottonwood Creeks in the northern and northwestern parts of the survey area and Union Flat, Rebel Flat, and Willow Creeks in the southern and southwestern parts. The southern part of the survey area consists of a narrow band of very steep soils along the Snake River Canyon that drain directly into the Snake River. Hangman Creek, a perennial tributary to the Spokane River, drains an area of about 20 square miles in the northeastern part of the county. Its drainage water ultimately flows into the Columbia River. Wheat is the major cultivated crop. Barley, peas, lentils, grass, and alfalfa are other important crops. Soils on the breaks of the Snake River, on the chan- neled scablands, and on the buttes are used mostly for range and wildlife habitat. Others who contributed to the soil survey are JOHNATHAN P. EDWARDS, JACK L. WOOD, DALE L. OLSON, CLINTON B. LEON- ARD, PAUL E. RASMIUSSEN, BERT J. JAHN, and PHILLIP S. GALE.

Figure 1.-Location of Whitman County in Washington. the soils of one series have major horizons that are fail on a given kind of soil, and they relate this to the similar in thickness, arrangement, and other important slow permeability of the soil or its high water table. characteristics. Each soil series generally is named for a They see that streets, road pavements, and foundations for town or other geographic feature near the place houses are cracked on a named kind of soil and they relate where a soil of that series was first observed and this failure to the high shrink-swell potential of the mapped. Palouse and Naff, for example, are the names of soil material. Thus, they use observation and two soil series. All the soils in the United States knowledge of soil properties, with available research having the same series name are essentially alike in data, to predict limitations or suitability of soils for those characteristics that affect their behavior in the present and potential uses. undisturbed landscape. After data have been collected and tested for the Soils of one series can differ in texture of the surface key, or benchmark, soils in a survey area, the soil layer and in slope, stoniness, or some other scientists set up trial groups of soils. They test these characteristic that affects use of the soils by man. On groups by further study and by consultation with the basis of such differences, a soil series is divided into farmers, agronomists, engineers, and others. They then phases. The name of a soil phase indicates a feature adjust the groups according to the results of their that affects management. For example, Tekoa silt loam, studies and consultation. Thus, the groups that are 3 to 25 percent slopes, is one of several phases within finally evolved reflect up-to-date knowledge of the soils the Tekoa series. and their behavior under current methods of use and After a guide for classifying and naming the soils management. had been worked out, the soil scientists drew the boundaries of the individual soils on aerial photographs. These photographs show woodlands, buildings, field borders, General Soil Map trees, and other details that help in drawing boundaries The general soil map at the back of this survey accurately. The soil map at the back of this publication shows the soil associations in Whitman County. A soil was prepared from aerial photographs. association is a landscape that has a distinctive A mapping unit consists of all the areas shown on a proportional pattern of soils. It normally consists of one soil map that are identified by a common symbol. On most or more major soils and at least one minor soil, and it maps detailed enough to be useful in planning the is named for the major soils. The soils in one association management of farms and fields, a mapping unit is may occur in another, but in a different pattern. nearly equivalent to a soil phase. It is not exactly A map showing soil associations is useful to people equivalent, because it is not practical to show on such a who want a general idea of the soils in an area, who map all the small, scattered bits of soil of some other want to compare different parts of an area, or who kind that have been seen within an area that is want to know the location of large tracts that are dominantly of a recognized soil phase. suitable for a certain kind of land use. Such a map is a Some mapping units are made up of soils of useful general guide in managing a watershed, a different series, or of different phases within one series. wooded tract, or a wildlife area, or in planning One such kind of mapping unit is the soil complex. engineering works, recreational facilities, and A soil complex consists of areas of two or more soils, so community developments. It is not a suitable map for intermingled or so small in size that they cannot be planning the management of a farm or field, or for shown separately on the soil map. Each area of a selecting the exact location of a road, building, or similar complex contains some of each of the two or more dominant structure, because the soils in any one association soils, and the pattern and relative proportions are about ordinarily differ in slope, depth, stoniness, drainage, and the same in all areas. Generally, the name of a soil other characteristics that affect their management. complex consists of the names of the dominant soils, In order to show the relation of soils to landforms, a joined by a hyphen. Anders-Kuhl complex, 3 to 15 block diagram was made with the aid of a computer for percent slopes, is an example. each soil association. In most areas surveyed there are places that have not The soil associations in the survey area have been been classified by soil series. These places are shown grouped into five general kinds of landscapes for broad on the soil map and are described in the survey, but they interpretative purposes. Each of the groups and their are called miscellaneous areas and are given descriptive included soil associations is described in the following names. Rock outcrop is an example. pages. While a soil survey is in progress, the scientists take soil samples needed for laboratory measurements Very Deep Soils Formed in Loess on Uplands and for engineering tests. Laboratory data from the same kind of soil in other places are also assembled. This group is on hills and ridges on uplands. Data on yields of crops under defined practices are Elevation ranges from 1,200 to 3,000 feet. The average assembled from farm records and from field or plot annual precipitation ranges from 11 to 23 inches. experiments on the same kind of soil. Yields under Most of the soils in this group are used for dryland defined management are estimated for all the soils. farming. Soil scientists observe how soils behave when used as The seven associations in this group make up about 64 a growing place for native and cultivated plants, and percent of the county. as material for structures, foundations for structures, or covering for structures. They relate this behavior to properties of the soils. For example, they observe that 1. Walla Walla association filter fields for onsite disposal of sewage Well drained, moderately permeable silt loams are dominant in this association. This association is in the Risbeck soils are on south-facing upper side slopes. western part of the county. Parts of the association are Chard soils are on outwash terraces adjacent to surrounded by channeled scabland. The topography is channeled scablands. Ritzville soils are on south-facing fairly smooth and consists mainly of a series of hills that side slopes in the southeastern part of the association. are roughly parallel to each other, are oriented in a Endicott soils are on long narrow ridgetops, south- northeast-southwest direction, and are separated by U- facing side slopes, and low-lying broad benches. Walvan shaped draws (fig. 2). The hills have broad, slightly soils are on the north- and northeast-facing side slopes. rounded, gently sloping to moderately steep tops and Athena soils are on north-facing side slopes along the steep to very steep sides. Total relief of individual hills eastern edge of the association. Onyx and Hermiston is 50 to 120 feet. The area is slightly to moderately soils are nearly level and are in narrow drainageways dissected, and the drainage pattern is mainly subparallel. and on alluvial fans. Annual precipitation is 11 to 15 inches. Elevation The remaining soils in this association are ranges from 1,200 to 2,200 feet. dominantly deep, well drained silt loams. Hermiston This association makes up approximately 14 percent of soils have a strongly alkaline substratum, Chard soils the county. Walla Walla soils make up about 82 percent have a fine sandy loam substratum, and Endicott soils of the association; Risbeck soils about 6 percent; Chard, have a hardpan. Ritzville, Endicott, Walvan, and Athena soils about 7 Practically all areas of the nearly level to steep soils percent; Onyx and Hermiston soils about 3 percent; are farmed. Wheat, barley, grass, and alfalfa are the and small areas of other soils about 2 percent. principal crops. Summer fallow is used because the Walla Walla soils occupy most areas on the hills annual precipitation is too low to make annual cropping except the south-facing side slopes, narrow ridgetops, feasible. Most areas of the very steep soils are small and some of the north- and northeast-facing side and isolated. They are unfenced and are used for wildlife slopes. Typically, Walla Walla soils have a dark habitat and range. grayish brown and grayish brown silt loam surface layer about 16 inches thick, a brown and pale brown 2. Athena association silt loam subsoil extending to a depth of 41 inches, and a. pale brown silt loam substratum. In places the Well drained, moderately permeable silt loams are substratum is calcareous in the lower part. dominant in this association. This association is domi- nantly in the western part of the county, east of the

Figure 2.-Typical landscape in the Walla Walla association.

side slopes and narrow ridgetops. Mondovi, Hermiston, Walla Walla association. It also is in the southeastern Covello, and Pedigo soils are in narrow drainageways and part of the county. The topography is fairly smooth and on alluvial fans. Palouse and Thatuna soils are on consists chiefly of a series of main hills or ridges and north- and northeast-facing side slopes at the eastern numerous small spur ridges extending outward from edge of this association. them (fig. 3). The hills and ridges are separated by U- The remaining soils in this association are shaped draws. The ridges have slightly rounded, gently dominantly deep silt loams. Lance soils are calcareous sloping to moderately steep tops and moderately steep to at or near the surface; Covello, Pedigo, and Thatuna very steep sides. The north- and northeast-facing sides soils have restricted drainage; and Thatuna soils have are generally shorter and steeper than the south- and a silty clay loam subsoil. Hermiston and Pedigo soils west-facing sides. Total relief of individual hills is 60 are strongly alkaline. to 200 feet. The area is slightly to moderately Practically all areas of the nearly level to steep soils dissected, and the drainage pattern is subparallel. are farmed. Wheat, barley,, peas, alfalfa, and grass are Annual precipitation is 15 to 18 inches. Elevation ranges the principal crops. A farming system of annual from 1,600 to 3,000 feet. cropping and intermittent fallow is used. Most areas of This association makes up approximately 12 percent of the very steep soils are small and isolated. They are the county. Athena soils make up about 84 percent of the unfenced and are used for wildlife habitat and range. association; Lance and Calouse soils about 12 percent; Mondovi, Covello, Hermiston, and Pedigo soils about 2 3. Athena-Calouse association percent; Palouse and Thatuna soils about 1 percent; and small areas of other soils about 1 percent. Well drained, moderately permeable silt loams are Athena soils occupy most areas on the hills. dominant in this association. This association is in the Typically, Athena soils have a dark grayish brown central part of the county, east of the Athena and grayish brown silt loam surface layer about 20 association, and in a small area in the southeastern part. inches thick, a brown and pale brown silt loam subsoil The topography is fairly smooth and consists chiefly extending to a depth of 48 inches, and a light gray of irregularly oriented hills or ridges (fig. 4). The hills calcareous silt loam substratum. are separated by U-shaped and V-shaped draws. The Lance and Calouse soils are on south-facing upper hilltops are slightly rounded and are gently sloping to strongly sloping. In places are sharp-topped ridges

Figure 3.-Typical landscape in the Athena association.

Figure 4.-Typical landscape in the Athena-Calouse association. that have cirquelike amphitheater enclosures on the Lance soils are on south-facing upper side slopes northern sides. The sides of the hills are moderately and on narrow ridgetops. Palouse and Thatuna soils are steep to very steep. The north- and northeast-facing on north- and northeast-facing side slopes at the eastern sides are generally shorter and steeper than the south- edge of this association. Uhlig soils are on outwash and west-facing sides. Total relief of individual hills is terraces adjacent to channeled scablands. Snow soils are 100 to 220 feet. The area is intensely to very intensely on terraces and foot slopes. Mondovi and Covello dissected, and the drainage pattern is subparallel and soils are in narrow drainageways and on alluvial fans. dendritic. Annual precipitation is 16 to 18 inches. The remaining soils in this association are Elevation ranges from 1,850 to 2,900 feet. dominantly deep silt loams. Lance soils are calcareous The association makes up approximately 6 percent of throughout, Thatuna and Covello soils have restricted the county. Athena soils make up about 74 percent of drainage, and Thatuna soils have a silty clay loam the association; Calouse and Lance soils about 17 subsoil. percent; Palouse, Uhlig, Snow, and Thatuna soils about 6 Practically all areas of the nearly level to steep soils percent; Mondovi and Covello soils about 2 percent; and are farmed. Wheat, barley, peas, alfalfa, and grass small areas of other soils about 1 percent. are the principal crops. A system of annual cropping Athena soils occupy most areas on the hills except and intermittent fallow is used. Most areas of the very the south-facing upper side slopes and narrow ridgetops. steep soils are small and isolated. They are unfenced Typically, Athena soils have a dark grayish brown and and are used for wildlife habitat and range. grayish brown silt loam surface layer about 20 inches thick, a brown and pale brown silt loam subsoil that 4. Palouse association extends to a depth of 48 inches, and a light gray, calcareous silt loam substratum. Well drained, moderately permeable silt loams are Typically, Calouse soils are on south-facing upper dominant in this association. This association is mainly in side slopes and on narrow ridgetops. Calouse soils have a the central part of the county, east of the Athena- dark grayish brown silt surface layer about 12 inches Calouse association. A small area is in the southeastern thick, a brown silt loam subsoil extending to a depth of part of the county. The topography consists of a series of 32 inches, and a light gray and pale brown, irregularly oriented hills and ridges separated by U- calcareous silt loam substratum. shaped draws (fig. 5). The hilltops are mostly

Figure 5.-Typical landscape in the Palouse association. narrow and gently sloping to strongly sloping. Some lying hills, and the smaller areas are on low-lying have rather sharp tops. Cirquelike amphitheater shoulders, knobs, and interconnecting ridges, mainly in the enclosures are on northern sides of the hills in places. southeastern part of the association. Snow soils are on The side slopes are moderately steep to very steep. In terraces and foot slopes. Staley soils are on narrow some places they are fairly smooth and uniform, but in ridgetops. Garfield soils are on low-lying shoulders, other places they are rough and irregular. Side slopes knobs, saddles, and ridges, mainly in the southeastern facing north and northeast are generally shorter and part of the association. Covello, Latah, and Caldwell steeper than those facing south and west. Total relief of soils are in narrow drainageways and on alluvial fans. individual hills is 100 to 240 feet. The area is intensively to The remaining soils in this association are very intensively dissected, and the drainage pattern is dominantly deep silt loams. Thatuna, Caldwell, Latah, subparallel and dendritic. Annual precipitation is 18 to and Covello soils have restricted drainage ; Covello and 21 inches. Elevation ranges from 2,100 to 2,900 feet. Staley soils are calcareous at or near the surface; and This association makes up approximately 5 percent of Naff and Thatuna soils have a silty clay loam subsoil. the county. Palouse soils make up about 69, percent of Practically all areas of the nearly level to steep soils the association; Thatuna soils about 11 percent; Naff are farmed. Wheat, barley, peas, lentils, grass, and and Snow soils about 9 percent; Staley and Garfield alfalfa are the principal crops. An annual cropping soils about 7 percent; Covello, Latah, and Caldwell soils system is used. Most areas of very steep soils are small about 3 percent; and small areas of other soils about 1 and isolated. They are unfenced and are used for wildlife percent. habitat and range. Palouse soils are on south-facing side slopes, convex north-facing side slopes, and very small, oval, rather 5. Palouse-Staley association flat hilltops. Typically, Palouse soils have a dark grayish brown and grayish brown silt loam surface Well drained, moderately permeable silt loams are layer about 24 inches thick and a pale brown silt loam dominant in this association. This association is in the subsoil extending to a depth of 60 inches. north-central part of the county. The topography consists Thatuna soils are on concave and smooth, uniform, of irregularly oriented hills and ridges that have north- and northeast-facing side slopes. The larger areas narrow tops and are separated by U-shaped draws (fig. of Naff soils are on south-facing sides of lower 6). Cirquelike amphitheater enclosures are on the northern sides of the hills in places. Side slopes are

Figure 6.-Typical landscape in the Palouse-Staley association. strongly sloping to steep. Side slopes facing north and restricted drainage, and Thatuna soils have a silty clay northeast are generally shorter and steeper than those loam subsoil. facing south and west. Total relief of individual hills is 25 Practically all areas of the nearly level to steep soils to 160 feet. The area is intensely dissected, and the are farmed. Wheat, barley, peas, lentils, grass, and drainage pattern is subparallel and dendritic. Annual alfalfa are the principal crops. An annual cropping precipitation is 18 to 21 inches. Elevation ranges from system is used. Most areas of the very steep soils are 2,100 to 2,700 feet. small and isolated. They are unfenced and are used for This association makes up approximately 5 percent of wildlife habitat and range. the county. Palouse soils make up about 79 percent of the association; Staley soils about 11 percent; Thatuna soils 6. Palouse-Thatuna association about 8 percent; Covello soils about 1 percent; and small areas of other soils about 1 percent. Well drained and moderately well drained, Palouse soils are on south-facing side slopes and moderately permeable and moderately slowly permeable convex north-facing side slopes. Typically, Palouse soils silt loams are dominant in this association. This association have a dark grayish brown and grayish brown silt loam is in the eastern part of the county. The topography surface layer about 24 inches thick and a pale brown silt consists mainly of long, narrow, irregularly oriented loam subsoil that extends to a depth of 60 inches. hills or ridges separated by U-shaped draws (fig. 7). Staley soils are on narrow ridgetops. They have a Side slopes are strongly sloping to very steep. Side grayish brown silt loam surface layer 18 inches thick slopes facing north and northeast are generally shorter and a brown, moderately alkaline, calcareous silt loam and steeper than those facing south and west. Old, subsoil and substratum. resistant surfaces are exposed on sides of low-lying Thatuna soils are on north- and northeast-facing, knobs, and cirquelike amphitheater enclosures are on the concave and smooth, uniform side slopes. Covello soils are north sides of the hills in places. Total relief of in narrow drainageways and on alluvial fans. individual hills is 50 to 180 feet. The area is intensively The remaining soils in this association are dominantly dissected, and the drainage pattern is subparallel. deep silt loams. Covello and Thatuna soils have Annual precipitation is 19 to 22 inches. Elevation ranges from 2,200 to 2,900 feet. This association makes up approximately 13 percent of the county. Palouse soils make up about 62 percent

Figure 7.-Typical landscape in the Palouse-Thatuna association. of the association ; Thatuna soils about 16 percent; Naff nantly deep silt loams; Garfield soils, however, are silty soils about 7 percent; Garfield and Staley soils about 8 clay loams. Naff soils have a subsoil of silty clay loam, and percent; Latah and Caldwell soils about 5 percent; Tilma soils have a subsoil of silty clay. Staley soils are Tilma soils about 1 percent; and small areas of other calcareous throughout, and Caldwell and Latah soils soils about 1 percent. have restricted drainage. Palouse soils are on south-facing side slopes, convex Most of this association is farmed. Wheat, barley, north-facing side slopes, and very small, oval, rather peas, lentils, grass, and alfalfa are the principal crops. flat hilltops. Typically, Palouse soils have a dark grayish An annual cropping system is used. Some of the steeper brown and grayish brown silt loam surface layer about areas are used for wildlife habitat and range. 24 inches thick and a pale brown silt loam subsoil that extends to a depth of 60 inches. 7. Palouse-Thatuna-Naff association Thatuna soils are on concave and smooth, uniform, Well drained and moderately well drained, north- and northeast-facing side slopes. Typically, moderately permeable and moderately slowly permeable Thatuna soils have a dark grayish brown silt loam silt loams are dominant in this association. This surface layer about 16 inches thick. The subsoil is association is in the northeastern part of the county. brown silt loam to a depth of 33 inches, light brownish The topography consists mainly of irregularly oriented, gray silt loam to a depth of 39 inches, and pale brown sharp-topped ridges and rounded hills interspersed with and light yellowish brown silty clay loam to a depth of 60 U-shaped draws (fig. 8). Side slopes are strongly inches. sloping to steep. Side slopes facing north and The larger areas of Naff soils are on south-facing northeast are generally shorter and steeper than those sides of low-lying hills, and the smaller areas are on facing south and west. Old, resistant surfaces are exposed low-lying shoulders, knobs, and interconnecting ridges. as knobs. In places they are connected to the main hills Garfield soils are on low-lying shoulders, knobs, saddles, by spur ridges. Cirquelike amphitheater enclosures are on and ridges. Staley soils are on higher narrow ridgetops. the north-facing sides of some hills. Total relief of Tilma soils are on lower parts of north-facing convex individual hills is 25 to 130 feet. The area is side slopes, shoulders, and low-lying knobs. Latah and intensively dissected in most places, but in some places Caldwell soils are in narrow drainageways and on along the eastern edge of the association the topography alluvial fans. is subdued. Drainage patterns are subparallel and The remaining soils in this association are domi- dendritic.

Figure 8.-Typical landscape in the Palouse-Thatuna-Naff association.

Annual precipitation is 21 to 23 inches. Elevation ranges part is light yellowish brown silt loam that extends to a from 2,400 to 2,800 feet. depth of 60 inches. This association makes up approximately 9 percent of the Latah and Caldwell soils are in narrow county. Palouse soils make up about 46 percent of the drainageways and on alluvial fans. Garfield soils are on association; Thatuna soils about 30 percent; Naff soils low-lying shoulders, knobs, saddles, and narrow ridgetops. about 11 percent; Latah and Caldwell soils about 5 Staley soils are generally on higher narrow ridgetops. percent; Garfield and Staley soils about 5 percent; Tilma Tilma soils are on the lower part of convex side slopes, soils about 2 percent; and small areas of other soils shoulders, and low-lying knobs. about 1 percent. The other soils in this association are dominantly Palouse soils are on broad ridgetops and south-facing deep silt loams ; Garfield soils, however, are silty clay side slopes. Typically, Palouse soils have a dark grayish loams. Caldwell and Latah soils have restricted drainage, brown and grayish brown silt loam surface layer about 24 Tilma soils have a subsoil of silty clay loam or silty inches thick and a pale brown silt loam subsoil that clay, and Staley soils are calcareous below a depth of about extends to a depth of 60 inches. 18 inches. Thatuna soils are on smooth and concave, north- Most of the acreage of this association is farmed. facing side slopes and concave foot slopes. Typically, Wheat, barley, peas, lentils, grass, and alfalfa are the Thatuna soils have a dark grayish brown silt loam principal crops. An annual cropping system is used. surface layer about 16 inches thick. The subsoil is Some of the steeper areas are used for wildlife habitat brown silt loam to a depth of 33 inches, light brownish and range. gray silt loam to a depth of 39 inches, and pale brown and light yellowish brown silty clay loam to a depth of 60 Very Deep to Moderately Deep Soils Formed in inches. Loess and in Colluvium and Residuum from The larger areas of Naff soils are on undulating, Metasediments; on Buttes south-facing sides of low-lying hills, and the smaller These soils are on scattered, prominent buttes. Elevation areas are on low-lying shoulders, knobs, and ridges. ranges from 2,500 to 4,000 feet. The average annual Typically, Naff soils have a dark grayish brown silt precipitation ranges from 21 to 23 inches. loam surface layer about 9 inches thick. The upper part of These soils are used for dryland farming, range, the subsoil, to a depth of about 47 inches, is dark brown woodland, and wildlife habitat. and yellowish brown silty clay loam. The lower

The one association in this group makes up about 3 facing side slopes on lower parts of buttes. Typically, percent of the county. Palouse soils have a dark grayish brown and grayish brown silt loam surface layer about 24 inches thick 8. Palouse-Thatuna-Tekoa association and a pale brown silt loam subsoil that extends to a depth of 60 inches. Well drained and moderately well drained, moderately Thatuna soils are on upper concave side slopes, low permeable and moderately slowly permeable silt loams are concave foot slopes, and smooth uniform side slopes dominant in this association. This association is in the that extend in a northerly direction. Typically, Thatuna eastern part of the county. The topography consists of soils have a dark grayish brown silt loam surface layer high, isolated hills that are prominent on the landscape about 16 inches thick. The subsoil is brown silt loam to (fig. 9). The upper side slopes are moderately steep to a depth of 33 inches, light brownish gray silt loam to a very steep and the foot slopes are strongly sloping to depth of 39 inches, and pale brown and light yellowish steep. The drainage pattern is radial. Annual brown silty clay loam to a depth of 60 inches. precipitation is 21 to 23 inches. Elevation ranges from Tekoa soils are on flat butte tops and flat and 2,500 to 4,000 feet. concave upper sides of buttes. Typically, Tekoa soils have This association makes up approximately 3 percent of a dark grayish brown and grayish brown gravelly silt the county. Palouse soils make up about 28 percent of the loam surface layer about 7 inches thick; a brown and association; Thatuna soils about 18 percent; Tekoa pale brown gravelly loam subsoil that extends to a soils about 15 percent; Schumacher soils about 13 depth of 20 inches; and a yellow, very gravelly loam percent; Naff soils about 12 percent; Garfield and substratum that extends to metasediments at a depth of Staley soils about 5 percent; Tilma and Larkin soils 38 inches. about 4 percent; Latah, Caldwell, and Konert soils Schumacher soils are on gently sloping to steep side about 4 percent; and small areas of other soils about 1 slopes and foot slopes on buttes. Naff soils are on tops percent. of narrow ridges and on undulating south-facing side Palouse soils are on broad ridgetops and south-

Figure 9.-Typical landscape in the Palouse-Thatuna-Tekoa association. slopes which extend outward from sides of buttes. from 1,400 to 2,700 feet. The average annual precipitation Garfield soils are on tops of narrow ridges which ranges from 14 to 23 inches. extend outward from sides of buttes, low-lying shoulders, These soils are used for dryland farming, range, knobs, and saddles. Staley soils are on narrow ridges woodland, and wildlife habitat. which extend outward from sides of buttes. Tilma soils The one association in this group makes up about 14 are on the lower part of convex slopes, shoulders, and low- percent of the county. lying knobs. Larkin soils are on the foot slopes of buttes. Latah, Caldwell, and Konert soils are in narrow 9. Palouse-Athena association drainageways. Garfield and Konert soils in this association have a Well drained, moderately permeable silt loams are surface layer of silty clay loam, and the surface layer of dominant in this association. The association includes all the other remaining soils is dominantly silt loam. of the major drainageways in Whitman County, the Schumacher, Naff, Larkin, Tilma, and Konert soils have adjacent bottom lands, and the gently sloping to very a subsoil of silty clay loam or silty clay. Staley soils are steep side slopes that lead down to the drainageways (fig. calcareous below a depth of about 18 inches, and 10). Annual precipitation is 14 to 23 inches. Elevation Caldwell, Konert, and Latah soils have restricted ranges from 1,400 to 2,700 feet. drainage. This association makes up approximately 14 percent of Most of the soils on lower south- and west-facing the county. Palouse soils make up about 30 percent of the side slopes and a few soils on lower north- and east- association; Athena soils about 17 percent; Caldwell, facing side slopes are farmed. Wheat, barley, peas, Latah, Covello, Pedigo, Narcisse, Mondovi, Hermiston, lentils, grass, and alfalfa are the principal crops. An Onyx, and Konert soils about 21 percent; Thatuna, Walla annual cropping system is used. Most of the very steep Walla. Larkin, Chard, Calouse, Snow, Uhlig, and soils and soils on upper parts of south- and west-facing Spofford soils about 18 percent; Gwin, Tucannon, side slopes are used for range and for wildlife habitat. Almota, Kuhl, Alpowa, Linville, Speigle, Bakeoven, Some soils on north- and east-facing, moderately steep to and Asotin soils about 13 percent; and small areas of other very steep side slopes are used for woodland, woodland soils about 1 percent. grazing, and wildlife habitat. Palouse and Athena soils are in large areas with long, south-facing side slopes. Some of these areas are in the northeastern hart of the county and lack Athena soils; Very Deep Soils Formed in Loess; in Valleys some are in the western part of the county and lack Palouse soils. These soils are in the major drainageways and are on Typically, Palouse soils have a dark grayish brown the sides of the drainageways. Elevation ranges and grayish brown silt loam surface layer about 24

Figure 10.-Topical landscape in the Palouse Athena association. inches thick and a pale brown silt loam subsoil that ing, scarred basaltic plateau. The plateau has a few extends to a depth of 60 inches. moderately steep to very steep basalt cliffs, ledges, Typically, Athena soils have a dark grayish brown loess islands and a few rock colluvial slopes on the and grayish brown silt loam surface layer about 20 sides of buttes, mesas, and canyons (fig. 11). There are inches thick, a brown and pale brown silt loam subsoil that also many undrained basins and gently sloping and extends to a depth of 48 inches, and a light gray, strongly sloping outwash terraces that have moderately calcareous silt loam substratum. steep and steep side slopes. Much of the area has Caldwell, Latah, Covello, Pedigo, Konert, Narcisse, patterned ground, which is the general term applied to Modovi, and Onyx soils are in nearly level mounds, stone nets, and stone strips. Annual precipitation drainageways and alluvial fans. Hermiston soils are in is 11 to 15 inches. Elevation ranges from 540 to 2,050 narrow drainageways and alluvial terraces. Thatuna soils feet. are on north- and northeast-facing side slopes in the This association makes up approximately 9 percent of eastern part of the county. Larkin soils are mainly on the county. Anders soils make up about 25 percent of the valley sides of the Palouse River in the eastern part. association; Benge soils about 16 percent; Kuhl soils about Chard and Uhlig soils are on outwash terraces in the 16 percent; Bakeoven soils about 12 percent; Rock outcrop northwestern part of the county. Calouse and Walla about 6 percent; Emdent soils about 3 percent; Roloff, Walla soils are on south-facing side slopes. Calouse Beckley, Starbuck, Alpowa, Stratford, and Magallon soils soils are in the central part of the county, and Walla about 10 percent; Walla Walla, Chard, and Endicott soils Walla soils are in the western part. Snow soils are on about 6 percent; Hermiston, Onyx, and Pedigo soils terraces and foot slopes in the eastern part of the about 3 percent; and small areas of other soils about 3 county. Spofford soils occur as circular spots mainly on percent. broad, south-facing side slopes in the central part of the Anders soils are on mounds and are in intricate county. Gwin, Kuhl, and Bakeoven soils are on strongly patterns on the landscape with Kuhl soils. Typically, sloping to very steep south-facing side slopes. Tucannon, Anders soils have a dark grayish brown and grayish Almota, and Asotin soils are also mainly on south-facing brown silt loam surface layer about 11 inches thick and a side slopes. Alpowa, Linville, and Speigle soils are on dark brown and brown silt loam subsoil that extends to colluvial foot slopes and steep and very steep, north- basalt bedrock at a depth of 33 inches. facing colluvial slopes. Benge soils are on outwash terraces. Typically, Benge Of the remaining soils, Caldwell, Latah, Covello, Pedigo- soils have a dark grayish brown and grayish brown Konert, and Thatuna soils have restricted drainage; Gwin, silt loam surface layer about 16 inches thick and a Kuhl, and Bakeoven soils have bedrock near the surface brown silt loam subsoil that extends to a depth of 24 and are cobbly or very cobbly; and Larkin soils have a inches. The substratum to a depth of 30 inches is silty clay loam or silty clay subsoil. brown, very gravelly silt loam. Below this, it is very Most of the soils on very steep side slopes in the gravelly and cobbly loamy sand. western and southern parts of the county and on south- Kuhl soils are in areas between mounds. Typically, Kuhl and west-facing side slopes in the eastern part of the soils have a dark grayish brown and grayish brown county are used for range and for wildlife habitat. Many cobbly and gravelly silt loam surface layer about 10 soils on east- and north-facing side slopes in the eastern inches thick and a yellowish brown gravelly silt loam part of the county are used for woodland and woodland subsoil that extends to basalt bedrock at a depth of 16 grazing. The soils on nearly level bottom land and inches. gently sloping to steep side slopes are mainly farmed. Alpowa soils are on colluvial side slopes. Roloff and Wheat, barley, legumes, and grass are the principal Starbuck soils are in the southwestern part of the crops. association and have patterned ground. Roloff soils are on mounds. Bakeoven and Starbuck soils and Rock outcrop are in areas between the mounds. Emdent soils are Very Shallow to Moderately Deep Soils Formed in mainly in undrained basins, but they are in some Loess and Glacial Outwash; in Channeled nearly level drainageways. Beckley and Chard soils are Scablands on outwash terraces. Stratford and Magallon soils are on outwash terraces in the southwestern part of the This group occupies the basaltic plateaus. Elevation association. Walla Walla soils are on streamlined loess ranges from 540 to 2,300 feet. The average annual islands within the channeled scablands. Endicott soils are precipitation ranges from 11 to 18 inches. on low-lying broad benches along edges of channeled This group is used mainly for range and wildlife scabland and on ridgetops and margins of loess islands. habitat. Nearly level Hermiston, Onyx, and Pedigo soils are in The two associations in this group make up about 12 drainageways. percent of the county. Of the remaining soils in this association, Bakeoven and Starbuck soils are cobbly or very cobbly and are 10. Anders-Benge-Kuhl association. underlain by bedrock that is near the surface; Beckley, Stratford, and Magallon soils have coarse sand at a Well drained, moderately permeable silt loans and depth of 20 to 40 inches; Endicott and Boloff soils have a cobbly silt loans that are underlain by basalt bedrock or hardpan or basalt at a depth of 20 to 40 inches; and gravel are dominant in this association. This as- Emdent and Pedigo soils have restricted drainage. sociation is in the western part of the county. The Most areas of this association are used for range or for landscape consists of a gently sloping to strongly slop- wildlife habitat.

Figure 11.-Typical landscape in the Anders-Benge-Kuhl association.

11. Bakeoven-Tucannon-Cheney association Bakeoven soils have a grayish brown, very cobbly loam surface layer about 5 inches thick and a Well drained, moderately permeable and brown, very gravelly loam subsoil over basalt moderately slowly permeable, very cobbly loams and bedrock at a depth of 8 inches. silt loams that are underlain by basalt bedrock or Tucannon soils are on mounds. Typically, gravel are dominant in this association. This Tucannon soils have a dark grayish brown silt loam association is in the northern part of the county. The surface layer about 13 inches thick. The upper part landscape consists of a gently sloping to strongly of the subsoil, to a depth of 26 inches, is brown sloping, scarred basaltic plateau. This plateau has and pale brown silt loam. The lower part is pale moderately steep to very steep cliffs, ledges, loess brown gravelly silt loam that extends to basalt islands, and rocky colluvial slopes on side slopes of bedrock at a depth of 30 inches. buttes, mesas, and canyons (fig. 12). There are also Cheney soils are on outwash terraces. Typically, many undrained basins and gently sloping and Cheney soils have a dark grayish brown silt loam strongly sloping outwash terraces which may have surface layer about 16 inches thick and a brown moderately steep and steep sides. Much of the area gravelly loam subsoil that extends to a depth of 29 has patterned ground. The annual precipitation is 15 inches. The substratum, to a depth of 3 6 inches, to 18 inches. Elevation ranges from 1,600 to 2,300 is brown very gravelly loam. Below this, it is gravel, feet. cobbles, and sand. This association makes up approximately 3 percent Bakeoven and Gwin soils and Rock outcrop are of the county. Bakeoven soils make up about 24 in areas between the mounds. Uhlig soils are on percent of the association; Tucannon soils about 22 outwash terraces. Covello, Pedigo, and Emdent soils percent; Cheney soils about 15 percent; Gwin soils are on nearly level bottom lands and undrained about 12 percent; Rock outcrop about 8 percent; basins. Mondovi and Hermiston soils are on nearly Covello, Pedigo, Emdent, Mondovi, and Hermiston level bottom lands. Hesseltine soils are on outwash soils about 12 percent; Hesseltine, Speigle, and terraces in the northern part of this association. Uhlig soils about 6 percent; and small areas of other Steep and very steep Speigle soils are mainly on soils about 1 percent. north-facing colluvial side slopes. Tucannon and Bakeoven soils occur mainly in Of the remaining soils in this association, intricate patterns on the landscape with Gwin soils Mondovi, and Rock outcrop in areas of patterned ground. Typically,

Figure 12.-Typical landscape in the Bakeoven-Tucannon-Cheney association.

Hermiston, and Uhlig soils are very deep, well drained Snake River. The landscape consists of steep and very silt loams; Speigle soils are cobbly or very stony; steep canyon sides and gently sloping to moderately Hesseltine soils are underlain by sand, gravel, and steep terraces (fig. 13). Annual precipitation is 12 to 18 cobbles at a depth of 20 to 40 inches ; Gwin soils are inches. Elevation ranges from 640 to 2,800 feet. underlain by basalt bedrock at a depth of 10 to 20 This association makes up approximately 5 percent of inches; and Covello, Pedigo, and Emdent soils have the county. Kuhl soils make up about 30 percent of the restricted drainage. association; Alpowa soils about 18 percent ; Bakeoven, Most of this association is used for range and for Asotin, Walla Walla, Linville, Gwin, Athena, and Almota wildlife habitat. soils and Rock outcrop about 43 percent; Chard and Farrell soils about 4 percent; and small areas of other soils about 5 percent. Shallow to Very Deep Soils Formed in Residuum Kuhl soils occur in intricate patterns on the from Basalt; in Canyons landscape with Alpowa and Asotin soils, Bakeoven and Chard soils, and Rock outcrop. Typically, Kuhl soils This group occupies breaks of the Snake River. have a dark grayish brown and grayish brown cobbly Elevations range from 540 to 2,800 feet. The average and gravelly silt loam surface laver about 10 inches annual precipitation ranges from 11 to 18 inches. thick and a yellowish brown gravelly silt loam subsoil that This group is used mainly for range and wildlife extends to basalt bedrock at a depth of 16 inches. habitat. Alpowa soils are on colluvial foot slopes and steep The two associations in this group make up about 7 and very steep, north-facing colluvial side slopes. percent of the county. Typically, Alpowa soils have a dark grayish brown cobbly silt loam surface layer about 8 inches thick. The 12. Kuhl-Alpowa association underlying material is brown gravelly silt loam to a depth of 15 inches and brown, pale brown, and white gravelly Well drained, moderately permeable, cobbly silt loam to a depth of 44 inches. Fractured basalt is at a loams are dominant in this association. This association depth of 44 inches. The soil is calcareous and moderately is in the southern part of the county along the alkaline at a depth of less than 20 inches.

Figure 13.-Tr-pical landscape in the Kuhl-Alpowa association.

Large areas of Asotin soils are on long ridges with Starbuck and Alpowa soils occur in intricate patterns broad tops. Walla Walla soils are on long, broad on the landscape with Roloff, Bakeoven, Magallon, and ridgetops and join Athena soils on the upper edge and Stratford soils and Rock outcrop. Asotin soils on the lower edge. Linville soils are on Starbuck soils are on steep and very steep canyon steep and very steep, north-facing colluvial side slopes at sides. Typically, Starbuck soils have a grayish brown higher elevations than Alpowa soils. Gwin and Linville cobbly silt loam and brown gravelly silt loam surface soils occur in an intricate pattern on very steep, north- layer about 9 inches thick and a pale brown gravelly facing side slopes at higher elevations than Kuhl soils. loam subsoil that extends to basalt bedrock at a depth of Narrow areas of Almota soils join Athena soils on the 15 inches. upper edge and Kuhl soils on the lower edge of south-facing Alpowa soils are on steep colluvial foot slopes and side slopes. Chard soils are on outwash terraces at very steep, north-facing colluvial side slopes. Typically, elevations of less than 1,200 feet. Farrell soils are on Alpowa soils have a dark grayish brown cobbly silt outwash terraces below Chard soils. loam surface layer about 8 inches thick. The underlying Of the remaining soils in this association, Walla material to a depth of 15 inches is brown gravelly silt Walla, Athena, Chard, and Linville soils are very deep, well loam. Below this it is brown, pale brown, and white drained silt loams ; Gwin, Bakeoven, Asotin, and Almota gravelly loam that extends to a depth of 44 inches. soils are underlain by basalt near the surface or at a depth Fractured basalt is at a depth of 44 inches. The soil is of 20 to 40 inches; and Farrell soils are underlain by calcareous and moderately alkaline at a depth of more than coarse sand. 20 inches. Most areas of this association are used for range Larger areas of Roloff soils are on long, broad ridgetops. and wildlife habitat. Ritzville soils are mainly on long, broad ridgetops. Ritzville and Walla Walla soils are also on some of the 13. Starbuck-Alpowa association steep and very steep north-facing side slopes. Kuhl soils are in an intricate pattern with Alpowa soils on Well drained, moderately permeable, cobbly silt some of the very steep, north-facing side slopes at higher loams are dominant in this association. This association elevations. Bakeoven soils are on upper side slopes is in the southwestern part of the county along the adjacent to Rock outcrop. Farrell, Magallon, and Stratford Snake River. The landscape consists of steep and very soils are on outwash terraces at elevations of less than steep canyon sides and gently sloping to moderately steep 1,200 feet. terraces (fig. 14). Annual precipitation is 11 to 12 Of the remaining soils in this association, Ritzville and inches. Elevation ranges from 540 to 1,600 feet. Walla Walla soils are very deep, well drained silt loams ; This association makes up approximately 2 percent of Bakeoven and Kuhl soils are underlain by basalt near the the county. Starbuck soils make up about 27 percent of the surface; Roloff soils have basalt at a depth of 20 to 40 association; Alpowa soils about 23 percent; Roloff, inches; and Stratford, 11lagallon, and Farrell soils are Ritzville, Bakeoven, Walla Walla, and Kuhl soils and Rock underlain by coarse sand or very gravelly coarse sand. outcrop about 35 percent; Farrell, Magallon, and Most areas of this association are used for range or Stratford soils about 12 percent; and small areas of other for wildlife habitat. soils about 3 percent.

Figure 14.-Typical landscape in the Starbuck-Alpowa association.

Descriptions of the Soils can be found by referring to the "Index to Mapping Units" at the front of the survey. The soil series and mapping units in Whitman County The acreage and proportionate extent of each are described in this section. Each soil series is described mapping unit are shown in table 1. Many of the terms in detail, and then, briefly, each mapping unit in that series used in describing soils can be found in the Glossary at is described. Unless it is specifically mentioned otherwise, the end of this survey, and more detailed information about it is to be assumed that what is stated about the soil the terminology and methods of soil mapping can be series holds true for the mapping units in that series. obtained from the Soil Survey Manual (6). Thus, to get full information about any one mapping unit, it is necessary to read both the descriptions of the Almota Series mapping unit and the description of the soil series to which it belongs. The Almota series consists of well drained, strongly An important part of the description of each soil sloping to very steep soils underlain by basalt at a series is the soil profile, that is, the sequence of layers depth of 20 to 40 inches. The soils formed in loess from the surface downward to rock or other underlying that contained some volcanic ash in the upper part and material. Each series contains two descriptions of this material from underlying basalt in the subsoil. They are profile. The first is brief and in terms familiar to the on uplands along drainageways in the central and layman. The second is more detailed and is for those who southeastern parts of the county. The elevation is 1,500 to need to make thorough and precise studies of soils. 2,600 feet. The native vegetation is mainly bluebunch Color terms are for dry soil unless otherwise stated. wheatgrass and Idaho fescue. The annual precipitation The profile described in the series is representative for is 15 to 18 inches. The frost-free season is 130 to 140 mapping units in that series. If the profile of a given days. mapping unit is different from the one described for In a representative profile the surface layer is about 9 the series, these differences are stated in describing the inches thick. It is dark grayish brown silt loam that is mapping unit, or they are apparent in the name of the 3 percent basalt gravel. The subsoil, to a depth of 29 mapping unit. inches, is brown and pale brown silt loam that is 3 to 15 As mentioned in the section "How This Survey Was percent basalt gravel. The substratum, to a depth of Made," not all mapping units are members of a soil 35 inches, is white calcareous gravelly silt loam that is series. Riverwash and Rock outcrop, for example, do not about 40 percent basalt gravel. Basalt is at a depth of 35 belong to a soil series, but nevertheless, are listed in inches. alphabetic order with the soil series. Almota soils have moderate permeability. The available Preceding the name of each mapping unit is a symbol. water capacity is moderate or moderately high. Roots This symbol identifies the mapping unit on the detailed penetrate to bedrock. Almota soils are used mainly for soil map. Listed at the end of each description is the wheat, barley, alfalfa, grass, range, and wildlife capability unit and range site in which the mapping unit habitat. has been placed. Not all units are assigned to a range Representative profile of Almota silt loam, 7 to 25 site. The page where each soil is described percent slopes, in a cultivated field, 200 feet east and

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

dium platy structure parting to weak 2,300 feet north of the southwest corner of sec. 26, T. 16 medium prismatic; slightly hard, very N., R. 41 E.: friable, slightly sticky and slightly plastic; Ap1-0 to 3 inches; dark grayish brown (10YR many fine roots; common fine and 4/2) silt loam, very dark brown (10YR medium pores; 3 percent basalt 2/2) moist; weak fine and medium granular fragments; mildly alkaline; clear wavy structure; slightly hard, very friable, boundary. slightly sticky and slightly plastic; many B22-11 to 19 inches; brown (10YR 5/3) silt fine roots and few medium roots; many fine loam, dark brown (10YR 3/3) moist; and very fine pores; neutral; abrupt smooth moderate medium prismatic structure; boundary. slightly hard, very friable, slightly sticky Ap2-3 to 9 inches; dark grayish brown (10YR and slightly plastic; many fine roots; 4/2) silt loam, very dark brown (10YR common fine and medium pores; 3 percent 2/2) moist; weak very fine subangular small basalt fragments; mildly alkaline; blocky structure; slightly hard, very friable, clear wavy boundary. slightly sticky and slightly plastic; many B23-19 to 29 inches; pale brown (10YR 6/3) silt fine roots and few medium roots; many fine loam, brown (10YR 4/3) moist; moderate and very fine pores; neutral; abrupt smooth coarse and medium prismatic structure; boundary. slightly hard, friable, slightly sticky and B21-9 to 11 inches; grayish brown (10YR 5/2) silt slightly plastic; common fine roots; common loam, very dark grayish brown (10YR fine and medium pores; 3/2) moist; weak thin and me-

In a representative profile the surface layer is dark 15 percent basalt fragments; moderately grayish brown cobbly silt loam about 8 inches thick. alkaline; clear irregular boundary. The underlying material is brown and pale brown Cca-29 to 35 inches; white (10YR 8/2) gravelly gravelly- silt loam or loam to a depth of 27 inches and silt loam, light brownish gray (10YR 6/2) white calcareous gravelly loam to a depth of 44 inches. moist; massive; hard, firm, slightly sticky Basalt is at a depth of 44 inches. and slightly plastic; few medium and fine Alpowa soils have moderate permeability. The roots; common fine and medium pores avail able water capacity is moderately high or high. partially filled with lime; 40 percent basalt Roots penetrate to a depth of 40 to 60 inches or more. fragments; slightly effervescent; Alpowa soils are used mainly for range and for wildlife moderately alkaline; abrupt irregular habitat. boundary. Representative profile of Alpowa cobbly silt loam, 30 IIR-35 inches; fractured basalt; lime in some to 65 percent slopes, in an area of grassland, 3,500 fractures. feet south and 200 feet east of the northwest corner of sec. 18, T. 11 N., R. 56 E. Depth to bedrock is 20 to 40 inches. The control A1-0 to 8 inches ; dark grayish brown (10YR 4/2) section between a depth of 10 inches and bedrock is 18 to cobbly silt loam, very dark brown (10YR 25 percent clay. 2/2) moist; weak fine and medium granular The A horizon has value of 4 or 5 when dry and 2 structure; slightly hard, friable, slightly or 3 when moist. It has weak granular blocky, or platy sticky and slightly plastic; many fine roots; structure and is neutral or mildly alkaline. The B2 horizon many very fine pores; 25 percent gravel has value of 5 or 6 when dry and 3 or 4 when moist and it and cobbles of basalt; neutral ; clear wavy has chroma of 2 or 3 when moist or dry. It has weak boundary. blocky or prismatic structure. The Cca horizon has value C1-8 to 15 inches; brown (10YR 5/3) gravelly of 6 to 8 when dry and 4 to 7 when moist, and it has silt loam, dark brown (10YR 3/3) moist; chroma of 1 to 3 when dry or moist. It is moderately weak fine and medium subangular blocky alkaline to strongly alkaline. structure; slightly hard, friable, slightly 1-Almota silt loam, 7 to 25 percent slopes. This sticky and slightly plastic; many fine roots ; strongly sloping to moderately steep soil is on uplands many very fine pores; 35 percent gravel and along sides of drainageways. It has the profile described as cobbles; mildly alkaline ; clear wavy representative of the series. boundary. Included with this soil in mapping are areas of soils that C2-15 to 20 inches; brown (10YR 5/3) gravelly are less than 20 inches or more than 40 inches deep to loam, dark brown (10YR 3/3) moist; bedrock. Also included are a few areas of Rock outcrop and weak fine and medium subangular blocky circular areas called slick spots. structure; slightly hard, friable, slightly Runoff is medium, and the erosion hazard is moderate. sticky and slightly plastic; many fine roots; This soil is used mainly for wheat. barley, alfalfa, grass, many very fine pores; 35 percent gravel and range. Capability unit IVe-14 ; Loamy range site (L- and cobbles; mildly alkaline. 3). C3-20 to 27 inches; pale brown (10YR 6/3) 2-Almota silt loam, 25 to 65 percent slopes. This gravelly loam, dark brown (10YR 4/3) moderately steep to very steep soil is on south-facing sides moist; massive; slightly hard, friable, of drainageways. It has a profile similar to the one slightly sticky- and slightly plastic; many described as representative of the series, but the fine roots ; many very fine pores; 50 percent surface layer is thinner and there is a higher percentage gravel and cobbles; slightly effervescent; of gravel in the surface layer and subsoil. moderately alkaline; abrupt smooth Included with this soil in mapping are areas of soils that boundary. are less than 20 inches or more than 40 inches deep C4ca-27 to 44 inches; white (10YR 8/1) gravelly to bedrock and a few areas of Rock outcrop. loam, very pale brown (10YR 7/3) moist; Runoff is rapid or very rapid, and the hazard of erosion is massive; slightly hard, friable, slightly high to very high. sticky and slightly plastic; common fine This soil is used mainly for range and for wildlife roots; 35 percent gravel and cobbles; habitat. Capability unit VIe-1; North exposure range site violently effervescent; moderately alkaline. (N-2). R-44 to 60 inches; fractured basalt; lime, silica, and fines in some fracture plains. Alpowa Series Depth to bedrock is 40 to more than 60 inches. The The Alpowa series consists of deep, well drained, steep to profile is neutral to strongly alkaline and becomes more very steep, cobbly soils that formed in a mixture of loess, alkaline as depth increases. The control section between material weathered from basalt, and small amounts of depths of 10 and 40 inches is less than 18 percent clay volcanic ash. The soils are on south-facing colluvial sides and between 35 and 50 percent coarse fragments. of drainageways along the Snake and Palouse Rivers. The Depth to carbonates is 1.8 to 30 inches. elevation is 600 to 2,500 feet. The native vegetation is The A horizon has value of 4 or 5 when dry and 2 mainly bluebunch wheatgrass, Sandberg bluegrass, and or 3 when moist. It is 20 to 40 percent gravel, cobbles, or rabbitbrush. The annual precipitation is 12 to 16 inches. stones. The C1, C2, and C3 horizons have value of 4 or 5 The frost-free season is 135 to 155 days. when dry and 3 or 4 when moist. They are 25 to 45 percent gravel, cobbles, or stones. The C4ca horizon has value of 6 to 8 when dry and 4 to 7 when moist, and it has weak medium prismatic structure; slightly chroma of 1 to 3 when dry or moist. It is silt loam or hard, friable, slightly sticky and slightly loam and is 35 to 50 percent gravel, cobbles, or plastic; common roots; many fine pores; 10 stones. percent angular gravel and cobbles of 3-Alpowa cobbly silt loam, 30 to 65 percent slopes. basalt; mildly alkaline; gradual smooth This steep to very steep soil is on sides of boundary. drainageways. B22-16 to 25 inches; brown (10YR 5/3) silt Included with this soil in mapping are areas of Rock loam, dark brown (10YR 3/3) moist; outcrop, soils that are less than 40 inches deep to moderate medium prismatic structure; basalt, and small areas of soils that are more than 60 slightly hard, friable, slightly sticky and inches deep to basalt and do not have gravel, cobbles, or slightly plastic; common roots ; many fine stones. pores; 10 percent subangular gravel and Runoff is rapid or very rapid, and the hazard of erosion is cobbles of basalt; mildly alkaline; gradual high or very high. smooth boundary. This soil is used mainly for range and for wildlife B23-25 to 32 inches; brown (10YR 5/3) silt habitat. Capability unit VIIe-1; North exposure range loam, dark brown (10YR 4/3) moist ; site (N-1). weak medium prismatic structure; slightly hard, friable, slightly sticky and slightly Anders Series plastic; common roots; many fine pores; 10 percent subangular gravel and cobbles of The Anders series consists of gently sloping to basalt; mildly alkaline; abrupt smooth strongly sloping, well drained soils underlain by basalt at boundary. a depth of 20 to 40 inches. The soils formed in IIR-32 inches; basalt. glacial outwash that contained a mixture of loess and volcanic ash in the upper part. They are in the Depth to bedrock is 20 to 40 inches. The profile is channeled scablands in the southwestern part of Whitman neutral or mildly alkaline throughout. The control section, County. The elevation ranges from 1,000 to 1,800 feet. The between a depth of 10 inches and bedrock, is native vegetation is bluebunch wheatgrass and Idaho dominantly silt loam. It averages 16 to 18 percent clay, fescue. The annual precipitation is about 12 to 16 inches. and it is modified by as much as 50 percent basalt The frost-free season is about 135 to 150 days. gravel and cobbles in the subhorizon immediately above In a representative profile the surface layer is dark bedrock; however, the weighted average content of grayish brown and grayish brown silt loam about 11 coarse fragments in the control section is 3 to 25 inches thick. The subsoil, to a depth of 32 inches, is percent. dark brown and brown silt loam that is 10 percent The A horizon has value of 4 or 5 when dry and 2 or gravel and cobbles of basalt. Basalt is at a depth of 32 3 when moist. It is as much as 15 percent basalt inches. gravel. The B horizon has value of 4 or 5 when dry and 3 Anders soils have moderate permeability. The available or 4 when moist, and it has chroma of 3 or 4 when dry or water capacity is moderate to moderately high. Roots moist. It is silt loam or gravelly silt loam. In places the penetrate to bedrock. Anders soils are used mainly for IIR layer contains secondary lime in fractures of the range, wheat, barley, alfalfa, grass, and wildlife bedrock. habitat. 4-Anders silt loam, 3 to 15 percent slopes. This Representative profile of Anders silt loam, 3 to 15 gently sloping to strongly sloping soil is in areas of percent slopes, in an area of grassland, 1,800 feet east channeled scablands. It has the profile described as and 40 feet north of the southwest corner of sec. 2, T. representative of the series. 16 N., R. 39 E.: Included with this soil in mapping are small areas of A11-0 to 7 inches; dark grayish brown (10YR soils that are less than 10 inches deep to basalt, soils 4/2) silt loam, very dark brown (10YR that are more than 40 inches deep to basalt, and soils 2/2) moist; weak medium platy structure that are 20 to 40 inches deep over gravel. Also included parting to weak fine granular; slightly are wet basins and Rock outcrop. hard, very friable, slightly sticky and Runoff is slow or medium, and the hazard of erosion is slightly plastic ; many roots; 5 percent fine slight or moderate. gravel and cobbles of basalt; mildly alkaline; This soil is used mainly for range, wildlife habitat, abrupt smooth boundary. wheat, barley, alfalfa, and grass. Capability unit IIIe-6; A12-7 to 11 inches; grayish brown (10YR 5/2) silt Loamy range site (L-2). loam, very dark grayish brown (10YR 5-Anders-Kuhl complex, 3 to 15 percent slopes. 3/2) moist; weak thick platy structure These gently sloping to strongly sloping soils are in parting to weak medium subangular blocky; areas of channeled scablands. This complex consists of 40 slightly hard, friable, slightly sticky and percent Anders silt loam, 3 to 15 percent slopes, and 30 slightly plastic; many roots; common fine percent Kuhl cobbly silt loam that has slopes of 3 to 15 pores ; 5 percent fine gravel or cobbles of percent. The topography is characterized by numerous basalt; mildly alkaline; abrupt wavy mounds. The mounds range from 10 to 30 feet in diameter boundary. and are generally 1 to 4 feet high and 5 to 20 feet apart. B21-11 to 16 inches; dark brown (10YR 4/3) silt The Anders soil occupies the mounds, and the Kuhl soil loam, dark brown (10YR 3/3) moist; occupies the area between the mounds. The Anders soil has a profile similar to the one described as representative of the Anders series, but the surface layer is 2 to 3 inches thinner. The Kuhl soil in slightly hard, friable, slightly sticky and this complex has a profile similar to the one described as slightly plastic; many fine and very fine representative of the Kuhl series. roots; many fine and very fine pores; 3 Included with these soils in mapping are a few small percent basalt fragments; neutral ; clear areas of noncobbly soils, stony soils, soils that are more wavy boundary. than 40 inches deep over basalt, soils that are less B22-17 to 25 inches; brown (10YR 5/3) silt loam, than 10 inches deep over basalt, wet basins, and Rock dark brown (10YR 3/3) moist; weak outcrop. Included areas make up 30 percent of the medium prismatic structure; slightly hard, mapped acreage of this complex. friable, slightly sticky and slightly plastic; Runoff is slow or medium, and the hazard of erosion is many fine and very fine roots; many fine and slight or moderate. very fine pores; 3 percent basalt fragments; This complex is used mainly for range and wildlife mildly alkaline; gradual wavy boundary. habitat. Capability unit VIIs-1; Anders part in Loamy Cca-25 to 30 inches; light gray (10YR 7/2) range site (L-2), Kuhl part in Shallow range site (S-2). gravelly silt loam, light brownish gray (10YR 6/3) moist; massive; hard, firm, Asotin Series slightly sticky and slightly plastic; few very fine and fine roots; common very The Asotin series consists of strongly sloping to very fine and fine pores; 15 percent basalt steep, well drained soils underlain by basalt at a depth fragments; strongly effervescent; of 20 to 40 inches. The soils formed in a thin layer of moderately alkaline; clear wavy boundary. loess mixed with some volcanic ash and residuum IIR 30 inches; basalt, lime and few roots in weathered from the underlying basalt. They are on cracks. uplands in the southwestern part of the county. The steep soils border sides of drainageways. Elevation is Depth to bedrock is 20 to 40 inches. The control 1,200 to 2,500 feet. The native vegetation is mainly section, between a depth of 10 inches and bedrock, is 5 to bluebunch wheatgrass and Idaho fescue. The annual 35 percent coarse basalt fragments. It is less than 18 precipitation is 12 to 15 inches. The frost-free season is percent clay. 135 to 160 days. The A horizon has value of 4 or 5 when dry and 2 or 3 In a representative profile the surface layer is about 10 when moist, and it has chroma of 2 or 3 when moist or dry. inches thick. It is dark grayish brown and grayish It is neutral to mildly alkaline. The B2 horizon has value of brown silt loam that is 2 percent basalt gravel. The 5 or 6 when dry and 3 or 4 when moist, and it has chroma subsoil, to a depth of 25 inches, is brown silt loam that is 3 of 2 or 3 when moist or dry. It is neutral to moderately percent basalt gravel. The substratum, to a depth of 30 alkaline. The Cca horizon has value of 6 to 8 when dry inches, is light gray calcareous gravelly silt loam. Basalt is and 5 to 7 when moist, and it has chroma of 2 or 3 at a depth of 30 inches. when dry or moist. It is moderately alkaline to strongly Asotin soils have moderate permeability. The available alkaline. water capacity is moderate or moderately high. Roots 6-Asotin silt loam, 7 to 25 percent slopes. This strongly penetrate to bedrock. Asotin soils are used mainly for sloping to moderately steep soil is on uplands near south- wheat, barley, grass, alfalfa, range, and wildlife facing sides of drainageways. It has the profile described habitat. as representative of the series. Included with this soil in Representative profile of Asotin silt loam, 7 to 25 mapping are soils that range from less than 10 inches to percent slopes, in a cultivated field, 1,700 feet west more than 60 inches deep to bedrock and soils that have and 1,400 feet north of the southeast corner of sec. slopes of less than 7 percent. Also included are circular 23, T. 14 N., R. 39 E. areas called slick spots. Ap-0 to 7 inches; dark grayish brown (10YR Runoff is medium, and the hazard of erosion is moderate. 4/2) silt loam, very dark brown (10YR This soil is used mainly for wheat, barley, alfalfa, 2/2) moist; weak fine and medium granular grass, and range. Capability unit IVe-13; Loamy range structure; slightly hard, friable, slightly site (L-2). sticky and slightly plastic; many fine and 7-Asotin silt loam, 25 to 65 percent slopes. This very fine roots; many fine and very fine moderately steep to very steep soil is on sides of pores; 2 percent basalt fragments; neutral; drainageways. It has a profile similar to the one clear wavy boundary. described as representative of the series, but the surface A12-7 to 10 inches; grayish brown (10YR-5/2) silt layer is 3 to 4 inches thicker and there is a higher loam, very dark grayish brown (10YR 3/2) percentage of gravel in the surface layer and subsoil. moist; weak fine and medium granular Included with this soil in mapping are areas of soils that structure; slightly hard, friable, slightly are less than 10 inches deep to bedrock, areas of soils sticky and slightly plastic; many fine and that are more than 40 inches deep to bedrock, and areas of very fine roots; many fine and very fine Rock outcrop. pores; 3 percent basalt fragments; neutral; Runoff is rapid to very rapid, and the hazard of clear wavy boundary. erosion is high to very high. B21-10 to 17 inches; brown (10YR 5/3) silt loam, This soil is used mainly for range and for wildlife dark brown (10YR 3/3) moist; weak habitat. Capability unit VIe-1; North exposure range site medium prismatic structure; (N-1).

Athena Series and slightly plastic ; few fine roots; few fine pores and common very fine pores ; The Athena series consists of deep, gently sloping to slightly effervescent; strongly alkaline. very steep, well drained soils that formed in loess and some volcanic ash. The soils are on uplands in the Reaction ranges from slightly acid to neutral in the A central part of the county. Elevation is 1,600 to 2,500 horizon, neutral to mildly alkaline in the B2 horizon, and feet. The native vegetation is mainly Idaho fescue, mildly alkaline to strongly alkaline in the C horizon. The bluebunch wheatgrass, and hawthorn. The annual control section between 10 and 40 inches is 18 to 23 precipitation is 15 to 18 inches. The frost-free season is percent clay. 130 to 140 days. The A horizon has value of 4 or 5 when dry and 2 or In a representative profile the surface layer is dark 3 when moist. The B2 horizon has value of 3 or 4 when grayish brown and grayish brown silt loam about 20 moist and 5 or 6 when dry, and it has chroma of 3 or 4 inches thick. The subsoil, to a depth of 48 inches, is when moist or dry. The C horizon has value of 4 to 6 brown and pale brown silt loam. The substratum, to a when moist and 6 to 8 when dry, and it has chroma of 2 depth of 60 inches, is light gray calcareous silt loam. to 4 when moist and dry. It is calcareous in some Athena soils have moderate permeability. The available places. water capacity is high. Roots penetrate to a depth of 60 8-Athena silt loam, 3 to 7 percent slopes. This inches or more. Athena soils are used mainly for wheat, gently sloping soil is on uplands and foot slopes. It has barley, peas, alfalfa, grass, range, and wildlife habitat. a profile similar to the one described as representative Representative profile of Athena silt loam, 7 to 25 of the series, but the surface layer is about 3 to 4 percent slopes, 2,400 feet south and 25 feet west of the inches thicker. northeast corner of sec. 19, T. 17 N., R. 42 E.: Included with this soil in mapping are small areas Ap-0 to 8 inches; dark grayish brown (10YR of soils that are steeper than this Athena soil and soils 4/2) silt loam, very dark brown (10YR that have lime at a depth of 20 to 40 inches. Also in- 2/2) moist; weak fine granular structure; cluded are circular areas called slick spots. slightly hard, friable, slightly sticky and Runoff is slow, and the hazard of erosion is slight. slightly plastic; many fine roots; common This soil is used mainly for wheat, barley, and peas. fine pores; neutral; abrupt wavy Capability unit IIe-2. boundary. 9-Athena silt loam, 7 to 25 percent slopes. This A12-8 to 15 inches; dark grayish brown (10YR strongly sloping and moderately steep soil is on up- 4/2) silt loam, very dark brown (10YR lands. Most areas of this soil have slopes of 7 to 20 2/2) moist; weak medium subangular percent. This soil has the profile described as represen- blocky structure; slightly hard, friable, tative of the series. slightly sticky and slightly plastic; many Included with this soil in mapping are small areas very fine and fine roots ; many very fine of soils where slopes are more than 25 percent or less pores; neutral; clear wavy boundary. than 7 percent; areas of soils on severely eroded ridges A13-15 to 20 inches; grayish brown (10YR 5/2) and knobs, some of which are calcareous; and small silt loam, very dark grayish brown (10YR circular areas called slick spots. 3/2) moist; weak fine and medium Runoff is medium, and the hazard of erosion is subangular blocky structure; slightly hard, moderate. friable, slightly sticky and slightly plastic; This soil is used mainly for wheat, barley, and peas. common fine and very fine roots ; many fine Capability unit IIIe-3. and very fine pores; neutral; clear wavy 10-Athena silt loam, 7 to 25 percent slopes, boundary. eroded. This strongly sloping and moderately steep soil B21-20 to 30 inches; brown (10YR 5/3) silt loam, is on uplands. It has a profile similar to the one dark brown (10YR 3/3) moist; moderate described as representative of the series, but the medium prismatic structure parting to surface layer is about 10 inches thick. moderate fine subangular blocky; slightly Included with this soil in mapping are small areas of hard, friable, slightly sticky and slightly soils that have lime on the surface and concave areas plastic; common fine and very fine roots; of soils that have a surface layer more than 20 inches many fine and very fine pores; neutral; clear thick. wavy boundary. Runoff is medium, and the hazard of erosion is mod- B22-30 to 48 inches; pale brown (10YR 6/3) erate. silt loam, dark brown (10YR 4/3) moist; This soil is used mainly for wheat, barley, alfalfa, moderate medium prismatic structure and grass. Capability unit IVe-3. parting to medium prismatic; slightly 11-Athena silt loam, 25 to 40 percent slopes. This hard, friable, slightly sticky and slightly moderately steep and steep soil is on uplands. The areas plastic; few very fine and fine roots; few of this soil that are on north-facing side slopes are fine pores and common very fine pores; generally free from lime, but some areas of this soil on mildly alkaline; abrupt wavy boundary. south-, southwest-, and southeast-facing side slopes have Cca-48 to 60 inches ; light gray (10YR 7/2) silt lime at a depth of 43 to 60 inches. This soil has a loam, pale brown (10YR 6/3) moist; profile similar to the one described as representative massive; hard, friable, slightly sticky of the series, but the surface layer is about 2 to 3 inches thinner. Included with this soil in mapping are small areas of eroded soils that are on ridges and knobs and that

are calcareous in places, concave areas of soils that tic; many fine roots; many very fine have a surface layer as much as 28 inches thick, vol- pores; about 40 percent coarse frag- canic ash spots, and Athena soils that have slopes of ments; neutral; clear wavy boundary. more than 40 percent. A12-1 to 5 inches; grayish brown (10YR 5/2) Runoff is rapid, and the hazard of erosion is high. gravelly loam, very dark grayish brown This soil is used mainly for wheat, barley, alfalfa, and (10YR 3/2) moist; weak fine and grass. Capability unit IVe-3. medium subangular blocky structure ; 12-Athena silt loam, 25 to 40 percent slopes, slightly hard, very friable, slightly sticky eroded. This moderately steep and steep soil is on up- and slightly plastic; many fine roots; lands. It has a profile similar to the one described as many very fine pores; about 40 percent representative of the series, but the surface layer is coarse fragments; neutral; clear wavy about 10 inches thick. Many small areas of this soil are boundary. shown on the map by a spot symbol. B2-5 to 8 inches; brown (10YR 5/3) very Included with this soil in mapping are small areas gravelly loam, dark brown (10YR 3/3) of soils that have lime on the surface and concave moist; weak fine and medium subangular areas of soils that have a surface layer more than 20 blocky structure; slightly hard, very inches thick. friable, slightly sticky and slightly Runoff is rapid or very rapid, and the hazard of plastic; many fine roots; common very fine erosion is high or very high. pores; about 60 percent coarse frag This soil is used mainly for wheat, barley, alfalfa, ments; neutral; abrupt wavy boundary. and grass. Capability unit VIe-2. IIR-8 inches; fractured basalt; fines and few 13-Athena silt loam, 40 to 55 percent slopes. This roots in fractures. steep and very steep soil is on north-, northwest-, and northeast-facing side slopes. It has a profile similar to Depth to bedrock is 6 to 10 inches. Coarse fragments the one described as representative of the series, but make up 50 to 75 percent of the profile. The profile the surface layer is more than 30 inches thick. ranges from neutral to mildly alkaline throughout. In Included with this soil in mapping are small areas places, lime and silica coatings are on the undersides of of severely eroded soils on ridges and knobs, pumice the gravel, cobbles, and stones. pockets on north- and northeast-facing side slopes, and The A horizon has value of 4 or 5 when dry and 2 soils that are 20 to 40 inches deep to basalt. or 3 when moist, and it has chroma of 2 or 3. It is loam or Runoff is very rapid, and the hazard of erosion is silt loam and is gravelly, cobbly, very cobbly, or stony. very high. The B horizon has value of 4 or 5 when dry and 3 or 4 This soil is used mainly for range and for wildlife when moist. It is loam or clay loam and is very gravelly, habitat. Capability unit VIe-1; North exposure range cobbly, very cobbly, or stony. Clay films are on some site (N-2). basalt fragments or in fractures in the underlying bedrock. Bakeoven Series 14-Bakeoven-Tucannon complex, 0 to 30 percent slopes. These soils are on broad basalt plateaus in the The Bakeoven series consists of nearly level to mod- northeastern part of the county and on sides of erately steep, well drained, very cobbly soils underlain by drainageway s in the southern part. This complex basalt at a depth of 6 to 10 inches. The soils formed consists of 40 percent Bakeoven very cobbly loam that in loess, weathered basalt residuum, and colluvial has slopes of 0 to 30 percent; 30 percent Tucannon material. They are on side slopes of channeled silt loam, 7 to 25 percent slopes; and 20 percent Gwin scablands and sides of drainageways of the Snake and very cobbly silt loam that has slopes of 3 to 30 percent. Palouse Rivers. Elevation is 600 to 2,600 feet. The The Bakeoven soil has the profile described as representa- native vegetation is mainly Sandberg bluegrass and tive of the Bakeoven series. The Tucannon soil has a stiff sagebrush. The annual precipitation is 12 to 16 profile similar to the one described as representative of inches. The frost-free season is 130 to 155 days. the Tucannon series. In a representative profile the surface layer is gray- Included with these soils in mapping are steep soils ish brown very cobbly loam and gravelly loam about 5 on colluvial slopes, soils that are 20 to 40 inches deep to inches thick. The subsoil is brown very gravelly loam gravel and cobbles, and Rock outcrop. Included areas about 3 inches thick. Basalt is at a depth of 8 inches. make up 10 percent of the mapped acreage of this Bakeoven soils have moderately slow permeability. complex. The available water capacity is low. Roots penetrate Runoff is very slow to rapid, and the hazard of to bedrock. Bakeoven soils are used mainly for range erosion is slight to high. and for wildlife habitat. This complex is used mainly for range and for Representative profile of Bakeoven very cobbly wildlife habitat. Capability unit VIIs-1; Bakeoven part loam, in an area of Bakeoven-Tucannon complex, 0 to in Very Shallow range site and Tucannon part in 30 percent slopes, 800 feet east and 300 feet south of Loamy range site (L-3). the northwest corner of sec. 24, T. 13 N., R. 43 E.: A11-0 to 1 inch; grayish brown (10YR 5/2) Beckley Series very cobbly loam, very dark grayish brown (10YR 3/2) moist; weak fine The Beckley series consists of nearly level to steep, granular structure; slightly hard, very somewhat excessively drained soils underlain by coarse friable, slightly sticky and slightly plas- basaltic sand at a depth of 20 to 40 inches. The soils formed in loess over glacial outwash materials domi-

nantly of basaltic origin. They are on terraces and 3 when moist, and it has chroma of 2 or 3 when dry or terrace breaks of channeled scablands and along major moist. The B horizon has value of 4 or 5 when dry and 3 or drainageways in the western part of the county. Ele- 4 when moist, and it has chroma of 3 or 4 when dry vation is 700 to 2,000 feet. The native vegetation is or moist. Some pedons do not have a C horizon. The mainly bluebunch wheatgrass, Thurber needlegrass, and CI horizon, where present, has value of 5 or 6 when Sandberg bluegrass. The annual precipitation is 12 to dry and 3 or 4 when moist. The IIC2 horizon 15 inches. The frost-free season is 135 to 150 days. contains fine gravel with coatings of lime and fine In a representative profile the surface layer is grayish salts on the undersides. brown sandy loam about 14 inches thick. The subsoil, to 15-Becklev sandy loam, 0 to 20 percent slopes. This a depth of 18 inches, is brown coarse sandy loam. The nearly level to moderately steep soil is on terraces of substratum, to a depth of 23 inches, is pale brown channeled scablands and along major drainageways. It coarse sandy loam. Below this, to a depth of 60 inches, it has the profile described as representative of the series. is gray coarse basaltic sand. Included with this soil in mapping are small areas Beckley soils have moderately rapid permeability. The of soils underlain by gravel at a depth of 20 to 40 available water capacity is low or moderate. Roots inches. penetrate to a depth of 60 inches or more. Beckley soils Runoff is very slow to medium, and the erosion are used mainly for range and for wildlife habitat. Small hazard is slight or moderate. areas are used for wheat, barley, alfalfa, and grass. This soil is used mainly for wheat, alfalfa, grass, Representative profile of Beckley sandy loam, 0 to 20 range, and wildlife habitat. Capability unit IIIe-6; percent slopes, in an area of grassland, 2,600 feet east Sandy Loam range site. and 1,200 feet north of the southwest corner of sec. 17, 16-Beckley sandy loam, 20 to 40 percent slopes. This T. 15 N., R. 39 E.: moderately steep and steep soil is on terraces of A11-0 to 7 inches; grayish brown (10YR 5/2) channeled scablands and along major drainageways. It sandy loam, very dark grayish brown has a profile similar to the one described as represen- (10YR 3/2) moist; weak thin platy tative of the series, but the surface layer is 2 to 3 inches structure parting to weak fine and me- thinner. dium granular; soft, very friable, slightly Included with this soil in mapping are small areas sticky and slightly plastic; many roots; of soils that have a loam or sandy loam surface layer. many fine pores; 5 percent fine basalt Runoff is rapid, and the erosion hazard is high. gravel; mildly alkaline; clear wavy This soil is used mainly for wheat, barley, alfalfa, boundary. grass, range, and wildlife habitat. Capability unit IVe- A12-7 to 14 inches; grayish brown (10YR 5/2) 6; Sandy Loam range site. sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium Benge Series subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; The Benge series consists of nearly level to strongly common roots ; many fine and very fine sloping, well drained soils underlain by loose, very pores; 10 percent fine basalt gravel; gravelly and cobbly loamy sand at a depth of 20 to 40 mildly alkaline; clear wavy boundary. inches. The soils formed in glacial outwash materials that B2-14 to 18 inches; brown (10YR 5/3) coarse contained a mixture of loess in the upper part. They sandy loam, dark brown (10YR 3/3) moist; are on glacial outwash terraces of channeled scablands weak fine and medium subangular blocky in the western part of the county. Elevation is 1.200 to structure; soft, very friable, nonsticky and 1,800 feet. The native vegetation is mainly bluebunch nonplastic; common roots; many very fine wheatgrass and Idaho fescue. The annual precipitation and fine pores; 10 percent fine basalt is 12 to 15 inches. The frost-free season is 135 to 150 gravel; mildly alkaline; abrupt wavy days. boundary. In a representative profile the surface layer is dark C1-18 to 23 inches; pale brown (10YR 6/3) grayish brown and grayish brown silt loam about 16 coarse sandy loam, dark brown (10YR inches thick. The subsoil, to a depth of 24 inches, is 4/3) moist; single grained; loose, non- brown silt loam that is about 6 percent gravel. The sticky and nonplastic ; common roots ; 10 substratum, to a depth of 30 inches, is brown very percent fine gravel; mildly alkaline; clear gravelly silt loam. Below this, to a depth of 60 inches, wavy boundary. it is very gravelly and cobbly loamy sand. IIC2-23 to 60 inches; gray (10Y R 5/1) coarse Benge soils have moderate permeability at a depth of basaltic sand, very dark gray (10YR 3/1) 20 to 40 inches and very rapid permeability at a depth moist; single grained; loose; 5 percent of more than 40 inches. The available water capacity fine gravel ; moderately alkaline. is moderate to moderately high. Roots penetrate to a depth of 60 inches or more. Benge soils are used mainly Depth to coarse basaltic sand is 20 to 40 inches. The for wheat, alfalfa, grass, range, and wildlife habitat. control section, between depths of 10 and 40 inches, Representative profile of Benge silt loam, 3 to 8 percent is 3 to 20 percent coarse fragments. The profile is slopes, in an area of grassland, 1,100 feet west and neutral to moderately alkaline throughout. 600 feet south of the northeast corner of sec. 33, T. The A horizon has-value of 4 or 5 when dry and 2 or 16 N., R. 39 E.: A11-0 to 12 inches; dark grayish brown (10YR

4/2) silt loam, very dark brown (10YR range from 10 to 30 feet in diameter, and they are 2/2) moist; weak thick platy structure generally 10 to 30 feet apart. They are generally 1 to 4 parting to weak fine granular; slightly feet high. hard, friable, slightly sticky and slightly Included with this complex in mapping are soils that are plastic; many roots ; 1 percent very fine less than 20 inches or more than 40 inches deep to gravel ; mildly alkaline; clear smooth basalt, very stony soils, wet soils, and Rock outcrops. boundary. Included areas make up 20 percent of the mapped A12-12 to 16 inches; grayish brown (10YR 5/2) acreage of this complex. silt loam, very dark grayish brown Runoff is very slow to medium, and the erosion (10YR 3/2) moist; weak medium sub- hazard is slight or moderate. angular blocky structure; slightly hard, This complex is used for range and wildlife habitat. friable, slightly sticky and slightly plastic; Capability unit VIIs-1; Loamy range site (L-2). many roots; many fine pores; 2 percent very fine gravel ; mildly alkaline; clear Caldwell Series smooth boundary. B2-16 to 24 inches; brown (10YR 4/3) silt loam, The Caldwell series consists of nearly level, somewhat dark brown (10YR 3/3) moist; weak poorly drained soils that formed in alluvium from loess medium prismatic structure; slightly and some volcanic ash. The soils are on bottom lands hard, friable, slightly sticky and slightly in the eastern part of the county. Elevation is 1,700 to plastic; common roots; many fine pores; 6 2,600 feet. The native vegetation is mainly tufted percent gravel; mildly alkaline; abrupt hairgrass, sedges, and willow. The annual precipitation wavy boundary. is 18 to 23 inches. The frost-free season is 100 to 135 C1-24 to 30 inches; brown (10YR 5/3) very days. gravelly silt loam, brown (10YR 4/3) In a representative profile the surface layer is grayish moist; massive; soft, very friable, brown and dark gray silt loam about 17 inches thick. slightly sticky and slightly plastic; com- The subsoil, to a depth of 39 inches, is gray silty clay mon roots ; 90 percent gravel and cob- loam. The substratum, to a depth of 60 inches, is bles; moderately alkaline; abrupt wavy brownish gray silty clay loam. boundary. Caldwell soils have moderately slow permeability. The IIC2-30 to 60 inches; very gravelly and cobbly available water capacity is high. Roots penetrate to a loamy sand; coatings of lime on the un- depth of 60 inches or more. Caldwell soils are used mainly derside of some gravel and cobbles; mod- for wheat, barley, peas, lentils, clover, grass, range, and erately alkaline. wildlife habitat. Representative profile of Caldwell silt loam, in a Depth to very gravelly and cobbly loamy sand ranges cultivated area, 400 feet west and 200 feet north of the from 20 to 40 inches but is dominantly 20 to 36 inches. southeast corner of sec. 15, T. 15 N., R. 45 E. The control section, between depths of 10 and 40 Ap-0 to 9 inches; grayish brown (10YR 5/2) inches, averages less than 10 percent coarse fragments silt loam, very dark gray (10YR 3/1) and less than 50 percent fine or coarse sand in the moist; weak thick platy structure parting upper part. to weak fine granular; slightly hard, friable, The A horizon has value of 4 to 5 when dry and 2 or 3 slightly sticky and slightly plastic; many when moist. It is silt loam or loam and is gravelly in roots; common fine pores; neutral; abrupt places. The reaction is neutral to mildly alkaline. smooth boundary. 17-Benge silt loam, 3 to 8 percent slopes. This A12-9 to 17 inches; dark gray (10YR 4/1) silt gently sloping soil is on outwash terraces of channeled loam, black (10YR 2/1) moist; moderate scablands. It has the profile described as representative medium prismatic structure parting to of the series. moderate medium subangular blocky; Included with this soil in mapping are small areas hard, friable, sticky and slightly plastic; of Rock outcrop, stony soils, and soils underlain by common roots ; common fine pores; neutral; gravel at a depth of more than 40 inches. clear smooth boundary. Runoff is slow, and the erosion hazard is slight. A3-17 to 26 inches; dark gray (10YR 4/1) heavy This soil is used mainly for wheat, alfalfa, grass, silt loam, very dark gray (10YR 3/1) range, and wildlife habitat. Small areas are irrigated. moist; moderate medium prismatic structure Capability unit IIIe-6; Loamy range site (L-2). parting to moderate medium angular 18-Benge complex, 0 to 15 percent slopes. These blocky; hard, slightly firm, sticky and nearly level to strongly sloping soils are in mounded plastic; common roots; many fine pores; thin areas on glacial outwash terraces of the channeled patchy clay films; some organic staining on scablands. The complex consists of 55 percent Benge peds ; gray siliceous coating on vertical very cobbly silt loam in areas between mounds with peds; neutral; clear smooth boundary. slopes mostly between 0 and 15 percent and 25 percent B2-26 to 39 inches; gray (10YR 5/1) silty clay Benge silt loam, 3 to 8 percent slopes, in mounded loam, very dark gray (10YR 3/1) areas. Most of the slopes of more than 8 percent are moist; moderate medium prismatic structure along terrace breaks. These soils have a profile similar parting to moderate medium angular blocky; to the one described as representative of the series, but hard, firm, sticky, plastic; the Benge very cobbly silt loam that has 0 to 15 percent slopes has a very cobbly surface layer. The mounds

common roots ; common fine pores; thin the central part of the county. Elevation is 1,500 to patchy clay films; gray silt coatings on 2,600 feet. The native vegetation is mainly bluebunch peds; neutral; abrupt smooth boundary. wheatgrass and Idaho fescue. The annual precipitation is C1g-39 to 54 inches; light brownish gray (2.5Y 15 to 18 inches. The frost-free season is 120 to 140 6/2) silty clay loam, very dark grayish days. brown (2.5Y 3/2) moist; many fine dis- In a representative profile the surface layer is dark tinct yellowish brown (10YR 5/6) and grayish brown silt loam about 12 inches thick. The brown (7.5YR 4/4) mottles; massive; subsoil, to a depth of 32 inches, is brown silt loam. hard, firm, sticky and plastic; few roots; The substratum, to a depth of 60 inches, is pale brown few fine pores; few very thin clay films; and light gray calcareous silt loam. neutral; abrupt smooth boundary. Calouse soils have moderate permeability. The avail C2g-54 to 60 inches; light brownish gray (2.5Y able water capacity is high. Roots penetrate to a depth 6/2) light silty clay loam, dark grayish of 60 inches or more. Calouse soils are used mainly brown (2.5Y 4/2) moist; common fine for wheat, barley, peas, alfalfa, and grass. distinct mottles; massive; hard, firm, Representative profile of Calouse silt loam, 7 to 25 sticky and plastic; no roots ; few fine percent slopes, in an area of grassland, 1,700 feet tubular pores; neutral. north and 80 feet east of the southwest corner of sec. 2, T. 19 N., R. 41 E.: The control section, between depths of 10 and 40 A11-0 to 6 inches ; dark grayish brown (10YR 4/2) inches, is 25 to 30 percent clay. silt loam, very dark brown (10YR 2/2) The A horizon has value of 3 to 5 when dry and 2 or 3 moist; weak fine and medium subangular when moist, and it has chroma of 1 or 2. The B blocky structure; slightly hard, friable, horizon has value of 4 or 5 when dry and 3 or 4 when slightly sticky and slightly plastic; many moist, and it has chroma of 1 or 2. The C horizon has very fine and fine roots; few very fine and hue of 10YR or 2.5Y, value of 4 to 7 when dry and 2 to 4 fine pores; neutral; abrupt wavy boundary. when moist, and chroma of 1 or 2. Mottles range from A12-6 to 12 inches; dark grayish brown (10YR faint to distinct and have hue of 7.5YR to 10YR. The 4/2) silt loam, very dark brown (10YR gleyed horizon is silty clay loam or heavy silt loam. In 2/2) moist; weak fine and medium sub- places, small pockets of volcanic ash and basalt fragments angular blocky structure; slightly hard, are in the lower part of the profile. very friable, slightly sticky and slightly 19-Caldwell silt loam. This nearly level soil is on plastic; many very fine and fine roots; bottom lands. It has the profile described as representative many very fine and fine pores ; neutral ; of the series. clear wavy boundary. Included with this soil in mapping are small areas of B21-12 to 21 inches; brown (10YR 5/3) silt loam, poorly drained or moderately well drained soils and dark brown (10YR 3/3) moist; weak fine areas of soils where coarse sand or basalt are at a depth medium prismatic structure parting to of 20 to 40 inches. weak fine and medium subangular blocky; Runoff is very slow, and there is little or no hazard of slightly hard, friable, slightly sticky and erosion. This soil is subject to flooding during winter and slightly plastic ; many very fine and fine spring. A seasonally high water table is at a depth of 2 1/2 roots; many fine and very fine pores; neutral to 4 feet. ; clear wavy boundary. This soil is used mainly for wheat, barley, peas, B22-21 to 26 inches; brown (10YR 5/3) silt loam, lentils, clover, grass, range, and wildlife habitat. Capa- dark brown (10YR 3/3) moist; weak fine bility unit IIw-2 ; Wet Meadow range site. and medium prismatic structure parting to 20-Caldwell silt loam, drained. This nearly level soil is weak medium subangular blocky; slightly on bottom lands. It has a profile similar to the one hard, friable, slightly sticky and slightly described as representative of the series, but the dark plastic; many very fine and fine roots; many colored surface layer extends to a depth of 40 to 60 fine and very fine pores; few dark grayish inches. brown (10YR 4/2) organic coatings on Included with this soil in mapping are areas of peds and in root channels; neutral; clear somewhat poorly drained soils and small areas of well wavy boundary. drained soils. B3-26 to 32 inches; brown (10YR 5/3) silt loam, Runoff is very slow, and there is little or no hazard of dark brown (10YR 3/3) moist; weak erosion. This soil is subject to flooding during winter and medium prismatic structure parting to spring. A seasonally high water table is at a depth of 3 weak fine and medium subangular blocky; 1/2 to 5 feet. This soil has been artificially drained. slightly hard; friable, slightly sticky and This soil is used mainly for wheat, barley, oats, peas, slightly plastic; many fine and very fine lentils, clover, grass, and wildlife habitat. Capability roots; many fine and very fine pores; few unit IIw-2. fragments and coatings of lime in pores and root channels ; slightly effervescent, Calouse Series moderately alkaline; abrupt wavy boundary. The Calouse series consists of gently sloping to steep, C1ca-32 to 37 inches; light gray (10YR 7/2) well drained soils that formed in loess and some vol- canic ash underlain by calcareous loess. The soils are on ridgetops and south-facing side slopes and are in

silt loam, grayish brown (10YR 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; com- mon very fine and fine roots; many very fine and fine pores; lime throughout the matrix and concentrated in pores and root channels; violently effervescent; moderately alkaline; clear wavy boundary. C2ca-37 to 48 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; mas- sive; slightly hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine and fine pores; lime in root channels and pores; strongly effervescent; moderately alkaline; clear wavy boundary. C3ca-48 to 60 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; mas- sive; very hard, very firm, slightly sticky and slightly plastic; few roots; very fine and fine pores; lime in pores; strongly effervescent; moderately alkaline. The profile is neutral to moderately alkaline through out. The control section between depths of 10 and 40 inches is 18 to 23 percent clay. Depth to secondary lime is 20 to 40 inches. The A horizon has value of 4 or 5 when dry and 2 or 3 when moist, and it has chroma of 2 or 3 when dry or moist. The B2 and B3 horizons have value of 5 or 6 when dry or 3 or 4 when moist, and they have chroma of 3 or 4 when dry or moist. They are silt loam or light silty clay loam. The C horizon has value of 6 or 7 when dry and 4 or 5 when moist, and it has chroma of 2 or 3 when dry or moist. 21-Calouse silt loam, 3 to 7 percent slopes. This gently sloping soil is on south-facing side slopes on uplands. It has a profile similar to the one described as representative of the series, but the surface layer is 2 to 3 inches thicker (fig. 15). Included with this soil in mapping are soils that have lime at a depth of more than 40 inches. Runoff is slow, and the erosion hazard is slight. This soil is used mainly for wheat, barley, and peas. Capability unit IIe-2. 22-Calouse silt loam, 7 to 25 percent slopes. This strongly sloping to moderately steep soil is on south- facing side slopes on uplands. It has the profile de- scribed as representative of the series. Included with this soil in mapping are small areas of soils that have lime at a depth of more than 40 inches and areas of severely eroded soils, some of which are calcareous and are on narrow ridgetops and knobs. Runoff is medium, and the erosion hazard is moderate. This soil is used mainly for wheat, barley, and peas. Capability unit IIle-3. 23-Calouse silt loam, 5 to 25 percent slopes, eroded. This gently sloping to moderately steep soil is on Figure 15.-Profile of Calouse silt loam, 3 to 7 percent slopes. ridgetops, knobs, and south-facing side slopes on uplands. The lime accumulation is at a depth of about 3 feet. It has a profile similar to the one described as representative of the series, but the surface layer is 6 to 8 inches thick. of soils that have a surface layer 10 to 18 inches thick Included with this soil in mapping are concave areas and lime at a depth of more than 40 inches. Also in- cluded are areas, on the ridgetops and knobs, of soils that have lime at a depth of less than 20 inches. Runoff is medium, and the erosion hazard is mod- erate.

This soil is used mainly for wheat, barley, alfalfa, fine and fine roots; mildly alkaline ; and grass, Capability unit IVe-3. abrupt smooth boundary. 24-Calouse silt loam, 25 to 40 percent slopes. This A12-6 to 14 inches; grayish brown (10YR 5/2) silt moderately steep to steep soil is on south-facing side loam, very dark grayish brown (10YR 3/2) slopes on uplands. It has a profile similar to the one moist; weak fine and medium subangular described as representative of the series, but the surface blocky structure; soft, very friable, slightly layer is 7 to 9 inches thick. sticky and slightly plastic; many very Included with this soil in mapping are spots of fine and fine roots; many fine pores; severely eroded soils that are generally calcareous and mildly alkaline; clear wavy boundary. are on the narrow ridgetops and knobs. Also included are B2-14 to 22 inches; brown (10YR 5/3) silt loam, concave areas of soils that have a surface layer more dark brown (10YR 3/3) moist; weak fine than 18 inches thick and that have lime at a depth of and medium prismatic structure parting more than 40 inches. to fine and medium subangular blocky; Runoff is rapid, and the hazard of erosion is high. soft, friable, slightly sticky and slightly This soil is used mainly for wheat, barley, alfalfa, plastic; many very fine and fine roots; and grass. Capability unit IVe-3. many fine and fine pores ; moderately 25-Calouse silt loam, 25 to 40 percent slopes, alkaline; clear wavy boundary. eroded. This moderately steep and steep soil is on knobs IIC1-22 to 32 inches; brown (10YR 5/3) very and south-facing side slopes on uplands. It has a profile fine sandy loam, dark brown (10YR 3/3) similar to the one described as representative of the moist; massive; soft, very friable, slightly series, but the surface layer is 4 to 6 inches thick. sticky and slightly plastic; common roots ; Included with this soil in mapping are concave areas of many fine and very fine pores; 10 percent soils that have a surface layer 10 to 18 inches thick and coarse and very coarse basalt sand; that have lime at a depth of more than 40 inches. Also moderately alkaline; clear wavy boundary. included are areas of soils that have lime at a depth IIC2ca-32 to 40 inches; pale brown (10YR 6/3) of less than 20 inches on the ridgetops and knobs. fine sandy loam, dark brown (10YR 4/3) Runoff is rapid, and the erosion hazard is high. moist; massive; slightly hard, friable, This soil is used mainly for wheat, barley, alfalfa, nonsticky and nonplastic; few roots; many and grass. Capability unit VIe-2. fine pores; 15 percent coarse and very coarse basalt sand; strongly effervescent; Chard Series moderately alkaline; clear wavy boundary. IIC3ca-40 to 60 inches; light brownish gray The Chard series consists of gently sloping to mod- (10YR 6/2) fine sandy loam, dark grayish erately steep, well drained soils that formed in loess brown (10YR 4/2) moist; massive; and small amounts of volcanic ash and glacial outwash slightly hard, friable, nonsticky and non- material. The soils are on terraces that border chan- plastic; few very fine and fine roots ; 20 neled scablands and the Snake and Palouse Rivers and percent coarse and very coarse basalt their tributaries. Elevation is 600 to 1,700 feet. The sand; strongly effervescent; moderately native vegetation is mainly bluebunch wheatgrass and alkaline. Idaho fescue. The annual precipitation is 12 to 15 inches. The frost-free season is 135 to 150 days. The control section, between depths of 10 and 40 In a representative profile the surface layer is dark inches, is less than 5 percent coarse fragments. It is grayish brown and grayish brown silt loam about 14 silt loam in the upper part and loam, very fine sandy inches thick. The subsoil, to a depth of 22 inches, is loam, or fine sandy loam in the lower part. Depth to brown silt loam. The substratum, to a depth of 32 secondary carbonates is 28 to 40 inches. inches, is brown very fine sandy loam. Below this, to a Thickness of the A11 and A12 horizons ranges from depth of 60 inches, it is pale brown and light brownish 10 to 18 inches. The A1 horizon has value of 4 or 5 gray, calcareous fine sandy loam. Coarse sand and small when dry and 2 or 3 when moist. It is silt loam, loam, fragments of basalt are common throughout the profile. or very fine sandy loam and is neutral to mildly alka Chard soils have moderate or moderately rapid per- line. The B2 horizon has value of 4 or 5 when dry. It is meability. The available water capacity is high. Roots silt loam, loam, or very fine sandy loam and is neutral penetrate to a depth of 60 inches or more. Chard soils to mildly alkaline. The IIC1 and IIC2ca horizons have are used mainly for wheat, barley, range, and wildlife value of 5 or 6 when dry and 3 or 4 when moist, and habitat. Small areas are irrigated. they have chroma of 2 to 4 when dry or moist. They Representative profile of Chard silt loam, 7 to 15 are very fine sandy loam, fine sandy loam, or sandy percent slopes, in a cultivated field, 1,300 feet west and loam. Lenses of coarse sand and gravel are in the IIC1 1,000 feet north of the southeast corner of sec. 15, T. 15 and IIC2ca horizons. N., R. 39 E. 26-Chard silt loam, 3 to 7 percent slopes. This Ap-0 to 6 inches; dark grayish brown (10YR gently sloping soil is on terraces. It has a profile similar 4/2) silt loam, very dark brown (10YR to the one described as representative of the series, but 2/2) moist; weak fine and medium granular the surface layer is 2 to 4 inches thicker. structure; soft, very friable, slightly sticky Included with this soil in mapping are areas of soils and slightly plastic; many very that have a sandy loam surface layer, soils that have and slightly plastic; many roots; neutral; sand and gravel at a depth of 20 to 40 inches, and soils abrupt smooth boundary. that are silt loam to a depth of 60 inches. A12-7 to 16 inches; dark grayish brown (10YR Runoff is slow, and the erosion hazard is slight. 4/2) silt loam, very dark brown (10YR This soil is used mainly for wheat, barley, range, and 2/2) moist; weak fine and medium wildlife habitat. Capability unit IIe-1; Loamy range prismatic structure; slightly hard, site (L-2). friable, slightly sticky and slightly plastic; 27-Chard silt loam, 7 to 15 percent slopes. This many roots; many fine pores; 5 percent strongly sloping soil is on terraces. It has the profile gravel ; neutral; clear wavy boundary. described as representative of the series. B2-16 to 29 inches; brown (10YR 5/3) gravelly Included with this soil in mapping are areas of soils loam, dark brown (10YR 3/4) moist; that have a sandy loam surface layer, soils that have tweak fine and medium prismatic struc ture sand and gravel at a depth of 20 to 40 inches, and soils ; slightly hard, friable, slightly sticky and that are silt loam to a depth of 60 inches. slightly plastic; common roots; many fine Runoff is medium, and the erosion hazard is mod- pores; slightly effervescent on underside erate. of some pebbles; 15 percent gravel ; This soil is used for wheat, barley, range, and wild- mildly alkaline; clear wavy boundary. life habitat. Capability unit IIIe-2; Loamy range site C1-29 to 36 inches; brown (10YR 5/3) very (L-2). gravelly loam, dark brown (10YR 3/4) 28-Chard silt loam, 15 to 25 percent slopes. This moist; massive; slightly hard, friable, moderately steep soil is on terraces. It has a profile slightly sticky and slightly plastic; many similar to the one described as representative of the roots; many fine tubular pores; 40 percent series, but the surface layer is 3 to 5 inches thinner. gravel ; slightly effervescent on underside Included with this soil in mapping are areas of soils of some pebbles; mildly alkaline; clear that have a sandy loam surface layer, soils that have wavy boundary. sand and gravel at a depth of 20 to 40 inches, and soils IIC2-36 to 60 inches; sand, gravel, and cobbles, that are silt loam to a depth of 60 inches. dominantly basalt, few granite and Runoff is medium, and the erosion hazard is mod- quartzite ; some pebbles and cobbles have erate. lime coatings on underside. This soil is used mainly for wheat, barley, range, and wildlife habitat. Capability unit IIIe-2; Loamy Depth to sand, gravel, and cobbles ranges from 20 range site (L-2). to 40 inches. The A horizon is loam or silt loam and in places is Cheney Series very cobbly. Thickness of the A11 and A12 horizons ranges from 10 to 18 inches. The A horizon has value The Cheney series consists of nearly level to mod- of 4 or 5 when dry and 2 or 3 when moist. It is neutral erately steep, well drained soils underlain by sand, to mildly alkaline. The B2 horizon has value of 4 or 5 gravel, and cobbles at a depth of 20 to 40 inches. The when dry and 3 when moist, and it has chroma of 3 or soils formed in glacial outwash, loess, and volcanic 4 when dry or moist. It is silt loam or loam and in ash. They are on terraces in channeled scablands in the places is gravelly. The C1 horizon has value of 5 or 6 northwestern part of the county. Elevation is 1,700 to when dry and 3 when moist, and it has chroma of 3 or 2,200 feet. The native vegetation is mainly bluebunch 4 when dry or moist. It ranges from very gravelly wheatgrass and Idaho fescue. The annual precipitation sandy loam to very gravelly loam and is as much as 60 is 15 to 18 inches. The frost-free season is 130 to 140 percent coarse fragments. days. 29-Cheney silt loam, 0 to 7 percent slopes. This In a representative profile the surface layer is dark nearly level to gently sloping soil is on glacial outwash grayish brown silt loam about 16 inches thick. The terraces. It has the profile described as representative of subsoil, to a depth of 29 inches, is brown gravelly loam. the series. The substratum, to a depth of 36 inches, is brown very Included with this soil in mapping are soils with gravelly loam. Below this, to a depth of 60 inches, it gravel, cobbles, and sand at a depth of more than 40 is gravel, sand, and cobbles. inches; very stony soils; soils with basalt at a depth of Cheney soils have moderate permeability. The available 20 to 40 inches; and Rock outcrop. water capacity is moderate or moderately high. Roots Runoff is very slow or slow, and the erosion hazard is penetrate to a depth of 60 inches or more. Cheney soils slight. are used mainly for wheat, barley, range, and wildlife This soil is used mainly for wheat, barley, range, habitat. and wildlife habitat. Capability unit IIIe-7; Loamy Representative profile of Cheney silt loam, 0 to 7 range site (L-3). percent slopes, in an area of grassland, 2,200 feet west 30-Cheney very cobbly silt loam, 0 to 20 percent and 1,200 feet south of the northeast corner of sec. 17, slopes. This nearly level to moderately steep soil is on T. 20 N., R. 43 E.: glacial outwash terraces. It has a profile similar to the A11-0 to 7 inches; dark grayish brown (10YR one described as representative of the series, but the 4/2) silt loam, very dark brown (10YR surface layer is very cobbly and the subsoil has a 2/2) moist; weak fine granular structure; higher percentage of gravel and cobbles. slightly hard, friable, slightly sticky Included with this soil in mapping are areas of soils that are stony, soils with basalt at a depth of 10 to 40 IIC1-30 to 51 inches; white (10YR 8/1) silt inches, soils that do not have cobbles to a depth of 20 to loam, light brownish gray (10YR 6/2) 40 inches, and Rock outcrop. moist; massive; soft, very friable, Runoff is very slow to medium, and the erosion nonsticky and nonplastic ; very few fine hazard is slight or moderate. roots; common fine and medium pores; This soil is used mainly for range and for wildlife moderately alkaline; abrupt wavy habitat. Capability unit VIs-1 ; Loamy range site (L-3). boundary. IIIC2-51 to 60 inches; light brownish gray Covello Series (10YR 6/2) light silty clay loam, dark grayish brown (10YR 4/2) moist; The Covello series consists of nearly level, somewhat massive; hard, firm, sticky and plastic; poorly drained soils that formed in alluvium from very few fine roots; common. fine and loess and varying amounts of volcanic ash. The soils medium pores; moderately alkaline. are on bottom lands in the central part of the county. Elevation is 1,500 to 2,200 feet. The native vegetation is The control section, between depths of 10 and 40 mainly tufted hairgrass, sedges, and willows. The inches, is 12 to 18 percent clay. In places it has annual precipitation is 15 to 20 inches. The frost-free subhorizons of very fine sandy loam or light silty clay season is 130 to 145 days. loam. The profile is mildly to moderately alkaline In a representative profile the surface layer is dark throughout, and slight effervescence may occur in any grayish brown and grayish brown, calcareous silt loam horizon. about 30 inches thick. The underlying material, to a Thickness of the A horizon ranges from 24 to 40 depth of 51 inches, is white silt loam. Beneath this, to a inches. The A horizon has value of 4 or 5 when dry and 2 depth of 60 inches, is light brownish gray light silty or 3 when moist, and it has chroma of 1 or 2 when dry clay loam. or moist. The C horizon has value of 6 to 8 when dry Covello soils have moderate permeability. The available and 4 to 6 when moist. A few large, distinct mottles are water capacity is high. Roots penetrate to a depth of 60 in the C horizon. inches or more. Covello soils are used mainly for wheat, 31-Covello silt loam. This nearly level soil is on barley, legumes, grass, range, and wildlife habitat. bottom lands. It has the profile described as representative Representative profile of Covello silt loam, in an of the series. area of grass, 650 feet south and 400 feet east of the Included with this soil in mapping are areas of soils northwest corner of sec. 20, T. 16 N., R. 43 E.: that are strongly alkaline, soils that are moderately Ap-0 to 7 inches; dark grayish brown (10YR well drained, and soils that are not calcareous in the 4/2) silt loam, very dark brown (10YR surface layer or subsoil. 2/2) moist; weak fine granular structure; Runoff is very slow, and there is little or no hazard of slightly hard, friable, slightly sticky and erosion. This soil is subject to flooding during winter and slightly plastic; common fine and very fine spring. A seasonally high water table is within 2 to 4 roots; slightly effervescent; moderately feet of the surface. alkaline; abrupt smooth boundary. This soil is used mainly for wheat, barley, legumes, grass, A12-7 to 11 inches; dark grayish brown (10YR range, and wildlife habitat. Capability unit IIw-1; Wet 4/2) silt loam, very dark brown (10YR Meadow range site. 2/2) moist; weak coarse subangular 32-Covello silt loam, drained. This nearly level soil blocky structure or massive; slightly is on bottom lands. hard, friable, slightly sticky and slightly Included with this soil in mapping are areas of soils plastic; common fine roots; many fine and that are strongly alkaline. Soils that are somewhat medium pores; slightly effervescent; poorly drained, and soils that are not calcareous. moderately alkaline; abrupt wavy Runoff is very slow, and there is little or no hazard of boundary. erosion. This soil is subject to flooding during winter and A13-11 to 19 inches; dark grayish brown (10YR spring. A seasonally high water table is at a depth of 3 to 4/2) silt loam, very dark brown (10YR 5 feet. This soil has been drained. 2/2) moist; massive; slightly hard, fri- This soil is used mainly for wheat, barley, legumes, grass, able, slightly sticky and slightly plastic; and wildlife habitat. Capability unit IIw-1. common fine roots ; common fine and me- dium pores; slightly effervescent; mod- Emdent Series erately alkaline; clear wavy boundary. A14-19 to 30 inches; grayish brown (10YR 5/2) The Emdent series consists of nearly level, somewhat silt loam, very dark grayish brown (10YR poorly drained, saline-alkali soils that formed in alluvial 3/2) moist; massive; slightly hard, material from loess and volcanic ash. The soils are in friable, slightly sticky and slightly plastic; depressions, basins, and potholes in the southwestern part few fine roots; many fine and very fine of the county. Elevation is 900 to 1,900 feet. The native pores; slightly effervescent; moderately vegetation is mainly giant wildrye and saltgrass. The alkaline; abrupt wavy boundary. annual precipitation is 11 to 16 inches. The frost-free season is 135 to 145 days. In a representative profile the surface layer is grayish brown, strongly alkaline silt loam about 9 inches thick. The next layer, to a depth of 15 inches, is light gray, strongly alkaline silt loam. The underlying ma- terial, to a depth of 22 inches, is light gray, strongly moist and 1 when dry. The C4g horizon, where present, is alkaline silt loam. Next, to a depth of 46 inches, it is silt loam or silty clay loam. It has hue of 5Y, value of 5 light gray and white silt loam and loam. Below this, to or 6 when dry and 4 or 5 when moist, and chroma of 1 a depth of 60 inches, it is gray light silty clay loam. or 2 when dry or moist. Emdent soils have moderate permeability. The 33-Emdent silt loam. This nearly level soil is in available water capacity is high. Roots penetrate to a depressions, basins, and potholes. It has the profile depth of 60 inches or more. Emdent soils are used described as representative of the series. mainly for range and for wildlife habitat. Cultivated Included with this soil in mapping are a few areas of areas are used for wheat, barley, oats, legumes, and moderately well drained or well drained soils, areas of grass. soils that have bedrock at a depth of 20 to 40 inches, Representative profile of Emdent silt loam, in an and areas of Rock outcrop. area of grassland, 2,050 feet south and 300 feet west Runoff is ponded or very slow, and there is little or of the northeast corner of sec. 18, T. 14 N., R. 37 E.: no hazard of erosion. This soil is subject to ponding A1ca-0 to 9 inches; grayish brown (10YR 5/2) during winter and spring. A seasonally high water silt loam, very dark brown (10YR 2/2) table is at a depth of 2 to 4 feet. moist; weak very thin platy structure ; This soil is used mainly for range and for wildlife slightly hard, friable, slightly sticky and habitat. Capability unit VIw-1; Alkali range site. slightly plastic; many roots; violently 34-Emdent silt loam, drained. This nearly level soil is effervescent; strongly alkaline; abrupt in depressions and basins. It has a profile similar to the smooth boundary. one described as representative of the series, but the ACca-9 to 15 inches ; light gray (10YR 6/1) silt surface laver is 10 to 12 inches of recent alluvium. loam, gray (10YR 5/1) moist; weak fine Included with this soil in mapping are areas of granular structure; slightly hard, friable, somewhat poorly drained soils and areas of soils that slightly sticky and slightly plastic; many have bedrock at a depth of 20 to 40 inches. roots; many fine tubular pores; violently Runoff is ponded or very slow, and there is little or no effervescent ; strongly alkaline; clear wavy hazard of erosion. This soil is subject to ponding boundary. during winter and spring. A seasonally high water table Clca-15 to 22 inches; light gray (10YR 7/1) silt is at a depth of 3 to 5 feet. loam, grayish brown (10YR 5/2) moist; This soil is used mainly for legumes, grass, wheat, massive; slightly hard, friable, slightly barley, oats, range, and wildlife habitat. Capability unit sticky and slightly plastic; many roots; few IVw-2 ; Alkali range site. fine tubular pores; violently effervescent; strongly alkaline; clear wavy boundary. Endicott Series C2ca-22 to 29 inches; light gray (10YR 7/1) silt loam, light brownish gray (10YR 6/2) The Endicott series consists of gently sloping to moist; massive; soft, very friable, nonsticky strongly sloping, well drained soils that have a lime- and nonplastic; common roots; many silica cemented hardpan at a depth of 20 to 40 inches. interstitial pores; violently effervescent; The soils formed in loess and some volcanic ash. They moderately alkaline; clear wavy boundary. are on narrow ridgetops, southwest-facing side slopes, C3-29 to 46 inches; white (10YR 8/1) loam, light and terraces. Elevation is 1,700 to 2,200 feet. The native gray (10YR 7/2) and pale brown (10YR vegetation is mainly bluebunch wheatgrass and Idaho 6/3) moist; massive; soft, very friable, fescue. The annual precipitation is 12 to 15 inches. nonsticky and nonplastic ; few' roots; many The frost-free season is 135 to 155 days. interstitial pores; slightly effervescent; In a representative profile the surface layer is dark moderately alkaline; abrupt smooth grayish brown and grayish brown silt loam about 13 boundary. inches thick. The subsoil, to a depth of 29 inches, is C4g-46 to 60 inches; gray (5Y 6/1) silty clay brown silt loam. The substratum, to a depth of 39 loam, olive gray (5Y 4/2) moist; mod inches, is a white, indurated, lime-silica cemented hard- erate fine angular blocky structure; pan. Below this, to a depth of 60 inches, the substratum is hard, firm, sticky and plastic ; common pale brown silt loam. fine tubular pores; thin continuous clay Endicott soils have moderate permeability to a depth films on ped faces; strongly effervescent; of 20 to 40 inches and very slow permeability in the moderately alkaline. cemented area. The available water capacity is moderate or moderately high. Roots penetrate to the hardpan. The profile is moderately alkaline to strongly alkaline Endicott soils are used mainly for wheat, barley, range, throughout and is slightly effervescent to-violently and wildlife habitat. effervescent in all horizons. The control section, be- Representative profile of Endicott silt loam, 3 to 15 tween depths of 10 and 40 inches, is more than 60 percent slopes, in a cultivated field, 200 feet west and percent volcanic ash and 12 to 18 percent clay. 1,100 feet north of the southeast corner of sec. 24, T. The A1 horizon is 8 to 14 inches thick. It has value 17 N., R. 39 E.: of 4 or 5 when dry and 2 or 3 when moist, and it has Ap-0 to 7 inches ; dark grayish brown (10YR chroma of 1 or 2 when dry or moist. The C1ca, C2ca, 4/2) silt loam, very dark brown (10YR and C3 horizons have value of 6 to 8 when dry and 5 to 7 2/2) moist; weak fine and medium when moist, and they have chroma of 2 or 3 when granular structure; slightly hard, very friable, slightly sticky and slightly plastic;

many roots; many fine and very fine outwash from loess, volcanic ash, and basalt. The soils pores; neutral ; abrupt smooth boundary. are on terraces that border channeled scablands, are A12-7 to 13 inches; grayish brown (10YR 5/2) along the Snake River valley, and are in the south- silt loam, very dark grayish brown (10YR western part of the county. Elevation is 800 to 1,400 3/2) moist; weak coarse prismatic feet. The native vegetation is mainly bluebunch wheat- structure; slightly hard, very friable, grass and Sandberg bluegrass. The annual precipitation slightly sticky and slightly plastic; many is 11 to 12 inches. The frost-free season is 140 to 150 roots; many fine and very fine pores; days. neutral ; clear wavy boundary. In a representative profile the surface layer is grayish B21-13 to 23 inches; brown (10YR 5/3) silt loam, brown very fine sandy loam about 7 inches thick. The dark yellowish brown (10YR 3/4) moist; subsoil, to a depth of 20 inches, is brown very fine weak fine and medium prismatic structure; sandy loam. The substratum, to a depth of 53 inches, is slightly hard, friable, slightly sticky and light brownish gray, calcareous very fine sandy loam and slightly plastic; many roots; many fine fine sandy loam. Below this, to a depth of 60 inches is and very fine pores; mildly alkaline ; light grayish brown, coarse basaltic sand. gradual wavy boundary. Farrell soils have moderate permeability. The avail B22-23 to 29 inches; brown (10YR 5/3) silt able water capacity is high. Roots penetrate to a depth loam, dark yellowish brown (10YR 3/4) of 60 inches or more. Farrell soils are used mainly for moist; weak fine and medium prismatic wheat, alfalfa, grass, range, and wildlife habitat. structure; slightly hard, friable, slightly Representative profile of Farrell very fine sandy sticky and slightly plastic; many roots; loam, 7 to 25 percent slopes, in an area of grass, 3,040 many fine and very fine pores; mildly feet east and 2,960 feet south of the northwest corner alkaline; gradual wavy boundary. of sec. 34, T. 14 N., R. 34 E.: C1sim-29 to 39 inches; white (10YR 8/2) layers Ap-0 to 7 inches; grayish brown (10YR 5/2) of indurated lime-silica cemented hardpan very fine sandy loam, very dark grayish lenses that do not break down on acid brown (10YR 3/2) moist; weak fine sub- treatment alone; indurated layers angular blocky structure; soft, very friable, separated by light grayish brown (10YR nonsticky and nonplastic; common roots ; 6/2) silt loam; few roots extend into mildly alkaline; clear smooth boundary. cracks; strongly effervescent; moderately B2-7 to 20 inches; brown (10YR 5/3) very fine alkaline; clear wavy boundary. sandy loam, dark brown (10YR 3/3) moist; C2ca-39 to 60 inches; pale brown (10YR 6/3) weak fine and medium subangular blocky silt loam, dark brown (10YR 4/3) moist; structure; soft, very friable, nonsticky and massive; hard, friable, slightly sticky and nonplastic; common roots; moderately slightly plastic; violently effervescent; alkaline; abrupt smooth boundary. strongly alkaline. C1ca-20 to 39 inches; light brownish gray (10YR 6/2) very fine sandy loam, dark Depth to the lime-silica hardpan ranges from 20 to 40 grayish brown (10YR 4/2) moist; mas- inches. sive; soft, very friable, nonsticky and Thickness of the A horizon ranges from 7 to 18 nonplastic; common roots; common fine inches. The A horizon has value of 4 or 5 when dry pores; violently effervescent; strongly and 2 or 3 when moist. The B horizon has value of 5 or alkaline; clear wavy boundary. 6 when dry and 3 or 4 when moist. The C1sim C2ca-39 to 53 inches; light brownish gray (10YR horizon has value of 6 to 8 when dry and 4 to 6 when 6/2) fine sandy loam, dark grayish brown moist, and it has chroma of 1 to 4 when dry or moist. It (10YR 4/2) moist; massive; soft, very consists of indurated, lime-silica-cemented layers friable, nonsticky and nonplastic; common separated by lenses of friable, calcareous material. The roots; common fine pores; violently C2ca horizon has value of 6 to 8 when dry and 4 to 6 effervescent; strongly alkaline; clear wavy when moist. Fragments of lime-silica-cemented materials boundary. are common throughout the profile. IIIC3-53 to 60 inches; light grayish brown (10YR 35-Endicott silt loam, 3 to 15 percent slopes. This 6/2) coarse sand, dark grayish brown gently sloping to strongly sloping soil is on narrow (10YR 4/2) moist; single grained; loose; ridgetops, south-facing side slopes, and terraces. few roots; slightly effervescent; moderately Included with this soil in mapping are areas of soil that alkaline. do not have the indurated, lime-silica hardpan and soils that are underlain by basalt at a depth of 20 to 40 inches. Depth to secondary carbonates ranges from 20 to Runoff is slow or medium, and the erosion hazard is 40 inches. slight or moderate. Thickness of the A horizon ranges from 7 to 10 This soil is used mainly for wheat, barley, and range. inches. The A horizon has value of 4 or 5 when dry Capability unit IIIe-2 ; Loamy range site (L-2). and 2 or 3 when moist. It is very fine sandy loam or fine sandy loam. The B2 horizon has value of 4 or 5 Farrell Series when dry and 2 or 3 when moist. It is very fine sandy loam or loam and is mildly alkaline or moderately The Farrell series consists of nearly level to moder- ately steep, well drained soils that formed in glacial alkaline. The Cca horizon has value of 6 or 7 when dry structure parting to strong fine angular and 4 or 5 when moist. It is loam, very fine sandy blocky; very hard, very firm, sticky and loam, fine sandy loam, or coarse sandy loam. It is plastic; many very fine and fine roots; moderately alkaline or strongly alkaline and is slightly few very fine pores and many medium effervescent to violently effervescent. pores; continuous thin clay films on peds ; 36-Farrell very fine sandy loam, 0 to 7 percent slopes. very dark brown (10YR 2/2) moist stains This nearly level and gently sloping soil is on terraces. on peds; common fine concretions; neutral; It has a profile similar to the one described as clear wavy boundary. representative of the series, but the surface layer is 2 to B22t-27 to 48 inches ; light yellowish brown 3 inches thicker. (10YR 6/4) silty clay loam, dark brown Included with this soil in mapping are soils that are (10YR 4/3) moist; moderate coarse 20 to 40 inches deep to basaltic sand, silt loams more prismatic structure parting to strong fine than 60 inches deep, and soils that have basalt near angular blocky ; very hard, very firm, sticky the surface. and plastic; few very fine and fine roots; Runoff is very slow to slow, and the erosion hazard is common very fine pores and many medium slight. pores; continuous thin clay films on peds; This soil is used mainly for wheat, alfalfa, grass, very dark brown (10YR 2/2) moist stains range, and wildlife habitat. Capability unit IIIe-1; on peds ; common fine concretions; mildly Loamy range site (L-2). alkaline ; abrupt wavy boundary. 37-Farrell very fine sandy loam, 7 to 25 percent slopes. B3-48 to 60 inches; light yellowish brown (10YR This strongly sloping to moderately steep soil is on 6/4) silty clay loam, dark yellowish brown terraces. It has the profile described as representative of (10YR 4/4) moist; weak coarse prismatic the series. structure parting to strong fine angular Included with this soil in mapping are soils that are blocky; very hard, very firm, sticky and 20 to 40 inches deep to basaltic sand, silt loams more plastic; few fine roots ; few fine pores; than 60 inches deep, and soils that have basalt bedrock few very dark brown (10YR 2/2) moist at a depth of 10 inches or less. stains on peds; few fine concretions; Runoff is medium, and the erosion hazard is moderate. many thin clay films on peds; neutral. This soil is used mainly for wheat, alfalfa, grass, range, and wildlife habitat. Capability unit IIIe-1 ; The Ap horizon has value of 4 or 5 when dry and 3 or Loamy range site (L-2). 4 when moist, chroma of 2 or 3, and hue of 7.5YR to 10YR. It is slightly acid to neutral. The B2t horizon Garfield Series is 35 to 45 percent clay. It has value of 5 or 6 when dry and 3 or 4 when moist, chroma of 3 or 4, and hue of The Garfield series consists of gently sloping to mod- 7.5YR to 10YR. Few to common fine concretions are in erately steep, well drained, severely eroded soils that the B2t horizon. Few to common very dark brown formed in loess. The soils are on low-lying ridgetops (10YR 2/2) moist stains are on peds. In a few places and knobs in the eastern part of the county. Elevation calcium carbonate has accumulated in the lower part is 1,900 to 3,000 feet. The native vegetation is mainly of the B2 horizon. Reaction is neutral to moderately Idaho fescue and bluebunch wheatgrass. The annual alkaline. The B3 horizon has value of 5 or 6 dry and 4 precipitation is 18 to 23 inches. The frost-free season is or 5 moist, and it has chroma of 3 or 4. It is heavy silt 110 to 140 days. loam to silty clay loam and is neutral to moderately In a representative profile the surface layer is brown alkaline. silty clay loam about 6 inches thick. The subsoil ex- 38-Garfield silty clay loam, 3 to 25 percent slopes. tends to a depth of 60 inches. It is yellowish brown This gently sloping to moderately steep soil is on low silty clay loam to a depth of 27 inches and light lying ridgetops and knobs. yellowish brown silty clay loam below. Included with this soil in mapping are soils that have Garfield soils have slow permeability. The available lime on the surface, silt loams more than 60 inches water capacity is high. Roots penetrate to a depth of 60 deep, and soils that have a silt loam surface layer inches or more. Garfield soils are used mainly for underlain by a silty clay or silty clay loam subsoil. wheat, barley, peas, lentils, grass, and alfalfa. Runoff is slow to medium, and the erosion hazard Representative profile of Garfield silty clay loam, 3 to 25 is slight or moderate. percent slopes, in a cultivated field 1,900 feet west and This soil is used mainly for wheat, barley, peas, 1,900 feet south of the northeast corner of sec. 30, T. 15 lentils, grass, and alfalfa. Capability unit IVe-10. N., R. 45 E.: Ap-0 to 8 inches; brown (10YR 5/3) silty clay Gwin Series loam, dark brown (10YR 3/3) moist; moderate fine granular structure; hard, The Gwin series consists of gently sloping to very firm, sticky and plastic; common very fine steep, well drained, cobbly soils underlain by basalt at a and fine roots; many fine pores; slightly depth of 10 to 20 inches. The soils formed in colluvium from acid; abrupt smooth boundary. loess, volcanic ash, and residuum weathered from basalt. B21t-8 to 27 inches; yellowish brown (10YR 5/4) They are on south-facing valley walls and in channeled silty clay loam, dark brown (10YR 4/3) scablands in the eastern and northeastern parts of the moist; moderate medium prismatic county. Elevation is 1,600 to 3,000 feet.

The native vegetation is mainly bluebunch wheatgrass, gravelly loams that are less than 10 inches deep to Idaho fescue, and Sandberg bluegrass. The annual basalt, areas of stony and very stony soils, and areas of precipitation is 18 to 23 inches. The frost-free season is silt loams more than 60 inches deep. 115 to 145 days. Runoff is rapid or very rapid, and the erosion hazard is In a representative profile the surface layer is dark high or very high. grayish brown cobbly silt loam about 7 inches thick. These soils are used mainly for range and for wildlife The subsoil, to a depth of 13 inches, is brown very habitat. Capability unit VIIs-1; Gwin part in Shallow gravelly heavy silt loam. Below this, it is grayish brown range site (S-3), Linville part in North exposure range very gravelly heavy silt loam. Basalt is at a depth of 18 site (N-2). inches. 40-Gwin-Tucannon complex, 3 to 30 percent slopes. Gwin soils have moderately slow permeability. The These gently sloping to moderately steep soils are on available water capacity is low. Roots penetrate to south-facing side slopes in valleys. This complex consists bedrock. Gwin soils are used mainly for range and for of 60 percent Gwin cobbly silt loam that has slopes of wildlife habitat. They are mapped only in complex with 3 to 30 percent and 25 percent Tucannon silt loam, 7 to Tucannon and Linville soils. 25 percent slopes. The Gwin soil has the profile described Representative profile of Gwin cobbly silt loam, in an as representative of the Gwin series. area of Gwin-Tucannon complex, 3 to 30 percent Included with these soils in mapping are areas that slopes, 1,450 feet south of the east quarter-corner of are as much as 15 percent Rock outcrop, areas of very sec. 6, T. 15 N., R. 43 E.: gravelly loams less than 10 inches deep to bedrock, A1-0 to 7 inches; dark grayish brown (10YR areas of stony and very stony soils, and areas of silt 4/2) cobbly silt loam, very dark brown loams more than 60 inches deep. (10YR 2/2) moist; weak fine granular Runoff is slow to medium, and the erosion hazard is structure; slightly hard, friable, slightly slight or moderate. sticky and slightly plastic; many roots; 30 These soils are used mainly for range and for wild- percent coarse fragments ; neutral; clear life habitat. Capability unit VIIs-1; Gwin part in smooth boundary. Shallow range site (S-3), Tucannon part in Loamy range B21t-7 to 13 inches; brown (10YR 5/3) very site (L-3) gravelly heavy silt loam, dark brown (10YR 3/3) moist; weak medium pris- Hermiston Series matic structure parting to moderate fine subangular blocky; hard, friable, sticky The Hermiston series consists of nearly level, well and plastic; many roots; many fine pores; drained soils that formed in alluvium from loess and thin almost continuous clay films on volcanic ash. The soils are on bottom lands and low vertical ped faces; faint light gray terraces along the Snake River Valley and in drainage- (10YR 7/2) coatings on all ped faces ; 60 ways in the western part of the county. Elevation is percent angular basalt fragments; neutral; 900 to 2,000 feet. The native vegetation is mainly clear wavy boundary. bluebunch wheatgrass, Sandberg bluegrass, and giant B22t-13 to 18 inches; grayish brown (10YR 5/2) wildrye. The annual precipitation is 12 to 17 inches. very gravelly heavy silt loam, dark grayish The frost-free season is 130 to 155 days. brown (10YR 4/2) moist; weak fine In a representative profile the surface layer is dark blocky structure; hard, friable, sticky and grayish brown and grayish brown silt loam about 17 plastic; common roots; many fine tubular inches thick. The next layer, to a depth of 22 inches, is pores; thin continuous clay films ; 70 brown silt loam. The underlying material, to a depth of percent angular basalt fragments ; neutral; 60 inches, is light gray and very pale brown very fine abrupt irregular boundary. sandy loam and silt loam. R-18 inches; basalt, somewhat fractured. Hermiston soils have moderate permeability. The available water capacity is high. Roots penetrate to a Depth to bedrock ranges from 10 to 20 inches. depth of 60 inches or more. Hermiston soils are used The A horizon has value of 4 or 5 when dry and 2 or mainly for wheat, barley, and wildlife habitat. 3 when moist, and it has chroma of 1 or 2. It is 6 to 8 Representative profile of Hermiston silt loam, in a inches thick and is neutral to slightly acid. It is 3 to 30 cultivated area, 2,500 feet east and 2,700 feet south of percent angular basalt gravel, cobbles, and stones. The B the northwest corner of sec. 15, T. 15 N., R. 39 E.: horizon has value of 4 to 6 when dry and 3 or 4 when Ap-0 to -5 inches ; dark grayish brown (10YR moist, chroma of 2 or 3 when dry or moist, and hue of 4/2) silt loam, very dark brown (10YR 7.5YR and 10YR. It ranges from heavy silt loam to silty 2/2) moist; weak fine and medium granular clay loam. It is 50 to 80 percent angular basalt structure; slightly hard, friable, slightly fragments. In places, the bedrock has a very thin coating sticky and slightly plastic; many fine and of calcium carbonate. very fine roots; many fine and very fine 39-Gwin-Linville complex, 30 to 65 percent slopes. pores; neutral; clear wavy boundary. These steep to very steep soils are on south-facing A12-5 to 17 inches; grayish brown (10YR 5/2) valley walls. This complex consists of 60 percent Gwin silt loam, very dark grayish brown (10YR cobbly silt loam that has slopes 30 to 65 percent and 25 3/2) moist; weak fine and medium percent Linville silt loam, 30 to 65 percent slopes. subangular blocky structure; slightly Included with these soils in mapping are areas that are as much as 15 percent Rock outcrop, areas of very

hard, very friable, slightly sticky and is brown very gravelly sandy loam. Below a depth of slightly plastic; many very fine and fine 34 inches, it is water-worn loose sand, gravel, and roots ; many very fine and fine pores ; cobbles. mildly alkaline; clear wavy boundary. Hesseltine soils have moderate permeability to a AC-17 to 22 inches ; brown (10YR 5/3) silt loam, depth of 20 to 40 inches and very rapid permeability dark brown (10YR 3/3) moist; massive; at a depth of more than 40 inches. The available water slightly hard, very friable, slightly sticky capacity is moderate. Roots penetrate to a depth of 60 and slightly plastic; many very fine and fine inches or more. Hesseltine soils are used mainly for roots ; many very fine and fine pores; mildly woodland grazing and for wildlife habitat. alkaline; clear wavy boundary. Representative profile of Hesseltine cobbly silt loam, C1ca-22 to 30 inches; light gray (10YR 7/2) 0 to 30 percent slopes, in an area of woodland, 1,700 very fine sandy loam, brown (10YR 5/3) feet east and 1,900 feet north of the southwest corner moist; massive; soft, very friable, slightly of sec. 8, T. 20 N., R. 43 E.: sticky and slightly plastic; common very A1-0 to 4 inches ; brown (10YR 5/3) cobbly silt fine and fine roots; common very fine and loam, very dark grayish brown (10YR fine pores ; slightly effervescent ; 3/2) moist; weak fine granular structure; moderately alkaline; abrupt wavy slightly hard, friable, slightly sticky and boundary. slightly plastic; many roots; few fine C2ca-30 to 60 inches; very pale brown (10YR pores; 15 percent gravel and cobbles; 7/3) silt loam, brown (10YR 5/3) moist; neutral; abrupt smooth boundary. massive; slightly hard, very friable, A3-4 to 7 inches; brown (10YR 5/3) gravelly slightly sticky and slightly plastic; common loam, dark brown (10YR 3/3) moist; very fine and fine roots; common very weak fine and medium subangular blocky fine and fine pores; violently effervescent ; structure ; slightly hard, friable, slightly strongly alkaline. sticky and slightly plastic; common roots; few fine pores; 15 percent gravel and Depth to secondary lime ranges from 20 to 30 inches. cobbles ; distinct gray coatings on vertical The control section, between depths of 10 and 40 inches, ped faces; neutral; clear smooth boundary. is 12 to 18 percent clay. B1-7 to 15 inches; yellowish brown (10YR 5/4) Thickness of the A and AC horizons is more than 30 gravelly loam, dark yellowish brown inches in places. These horizons have value of 2 or 3 when (10YR 3/4) moist; weak fine and medium moist and 4 or 5 when dry, and they have chroma of subangular blocky structure; slightly hard, 2 or 3. They are neutral to moderately alkaline. The friable, slightly sticky and slightly plastic; Cca horizon has value of 4 or 5 when moist and 5 to 7 common roots ; few fine pores; 15 percent when dry, and it has chroma of 2 or 3. gravel and cobbles; thin patchy clay films 41-Hermiston silt loam. This nearly level soil is on on peds; distinct gray coatings on peds; bottom lands and low terraces. neutral; clear smooth boundary. Included with this soil in mapping are areas of soils that B2t-15 to 20 inches; yellowish brown (10YR 5/4) are not calcareous to a depth of 60 inches, areas of soils gravelly loam, dark yellowish brown (10YR that are silt loam to a depth of 60 inches, and small areas 3/4) moist; weak fine and medium of soils that are moderately alkaline to strongly alkaline subangular blocky structure; slightly hard, throughout. friable, slightly sticky and slightly plastic; Runoff is very slow, and there is little or no hazard of common roots; few fine pores; 35 percent erosion. Flooding sometimes occurs during unusual weather gravel and cobbles; thin continuous clay conditions. films on peds ; distinct gray coatings on peds; This soil is used mainly for wheat, barley, and wildlife neutral ; clear smooth boundary. habitat. Capability unit IIc-1. C1-20 to 27 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, dark brown Hesseltine Series (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; The Hesseltine series consists of nearly level to mod- common roots; few fine pores; 60 percent erately steep, well drained, cobbly soils underlain by gravel and cobbles; neutral; clear smooth water-worn loose sand, gravel, and cobbles at a depth of boundary. 20 to 40 inches. The soils formed in a thin mantel of C2-27 to 34 inches; yellowish brown (10YR 5/4) loess and volcanic ash underlain by glacial outwash. They very gravelly sandy loam, dark brown are on outwash terraces of channeled scablands in the (10YR 4/3) moist; massive; slightly hard, northwestern part of the county. Elevation is 1,600 to friable, slightly sticky and slightly plastic; 2,200 feet. The native vegetation is mainly bluebunch common roots; few fine pores; 70 percent wheatgrass, Idaho fescue, and ponderosa pine. The annual gravel and cobbles; neutral; abrupt wavy precipitation is 17 to 19 inches. The frost-free season is boundary. 120 to 140 days. IIC3-34 inches; loose sand, gravel, and cobbles In a representative profile the surface layer is brown cobbly silt loam and gravelly loam about 7 inches thick. The subsoil, to a depth of 20 inches, is yellowish brown gravelly loam. The substratum, to a depth of 34 inches, containing a small amount of fine material. A13-13 to 20 inches; dark gray (10YR 4/1) Depth to sand, gravel, and cobbles ranges from 20 to silty clay loam, black (10YR 2/1) moist; 40 inches. The profile is slightly acid to neutral strong fine subangular blocky structure; throughout. very hard, very firm, sticky and plastic; The A horizon has hue of 7.5YR or 10YR, value of 4 common roots; many fine pores; neutral ; or 5 when dry and 2 or 3 when moist, and chroma of 2 or clear wavy boundary. 3. The B2t horizon has hue of 10YR or 7.5YR, value B21tg-20 to 28 inches; dark gray (10YR 4/1) of 4 or 5 when dry and 3 or 4 when moist, and chroma silty clay loam, black (10YR 2/1) moist; of 3 or 4. Content of coarse fragments in the B2t few fine yellowish brown (10YR 5/6) horizon ranges from 35 to 50 percent. The C1 and C2 moist mottles ; strong subangular blocky horizons have value of 4 or 5 when dry and 3 or 4 when structure; very hard, very firm, sticky moist, and they have chroma of 3 or 4. They are 35 to 70 and plastic; few roots; many fine pores; percent gravel. few thin clay films on peds and in pores; 42-Hesseltine cobble silt loam. 0 to 30 percent neutral; gradual wavy boundary. ) B22tg-28 to 41 inches gray (10YR 5/1) silty slopes. This nearly level to moderately steep soil is on clay, very dark gray (10YR 3/1) moist; glacial outwash terraces. few fine yellowish brown (10YR 5/6) Included with this soil in mapping are areas of soils moist mottles; strong fine and medium that are less than 20 inches deep to basalt, stony areas, prismatic structure; very hard, very firm, small areas that are free of surface cobbles, and areas of sticky and plastic; few roots; many fine Rock outcrop. pores; few thin clay films on peds and in Runoff is slow to medium, and the erosion hazard is slight pores; neutral; gradual wavy boundary. to moderate. Cg-41 to 60 inches; gray (10YR 6/1) silt loam, This soil is used mainly for woodland grazing and dark gray (10YR 4/1) moist; massive; for wildlife habitat. Capability unit VIs-1. few fine dark brown (10YR 3/3) moist mottles ; hard, firm, sticky and plastic ; Konert Series few roots; few fine pores; few thin clay films in pores; neutral. The Konert series consists of nearly level, somewhat poorly drained soils that formed in alluvial material The A horizon has value of 3 or 4 when dry and 2 or from loess, weathered metasediment, and volcanic ash. The 3 when moist, and it has chroma of 1 or 2 when dry or soils are on bottom lands and alluvial fans adjacent to moist. It is silt loam or silty clay loam. The B horizon buttes in the eastern part of the county. Elevation is has value of 4 or 5 when dry and 2 or 3 when moist, and 2,000 to 2,800 feet. The native vegetation is mainly reed it has chroma of 1 or 2 when dry or moist. It is silty clay canarygrass, willows, and hawthorne. The annual loam, clay loam, or silty clay. The C horizon has value of 5 precipitation is 20 to 23 inches. The frost-free season is 90 or 6 when dry and 3 or 4 when moist. It is silt loam, silty to 110 days. clay loam, or clay loam. In a representative profile the surface layer is dark gray 43-Konert silty clay loam. This nearly level soil is on silty clay loam about 20 inches thick. The subsoil, to a bottom lands. It has the profile described as re- depth of 41 inches, is gray silty clay loam in the upper presentative of the series. part and gray silty clay in the lower part. The Included with this soil in mapping are areas of soils substratum, to a depth of 60 inches, is gray silt loam. that have a silt loam surface layer and soils that are silt Konert soils have slow permeability. The available water loam to a depth of 60 inches. capacity is high. Root penetration is limited by the water Runoff is very slow, and there is little or no hazard of table and by the silty clay in the lower part of the subsoil. erosion. This soil is subject to flooding during winter and Konert soils are used mainly for wheat, barley, legumes, spring. A seasonally high water table is at a depth of 1 grass. range, and wildlife habitat. 1/2 to 2 1/2 feet. Representative profile of Konert silty clay loam, in an This soil is used mainly for wheat, barley, legumes, area of grassland, 1,400 feet east and 1,000 feet north grass, range, and wildlife habitat. Capability unit IVw- of the southwest corner of sec. 20, T. 14 N., R. 46 E.: 1: Wet Meadow range site. A11-0 to 4 inches; dark gray (10YR 4/1) silty 44 Konert silt loam. This nearly level soil is on alluvial clay loam, black (10YR 2/1) moist; strong fans and bottom lands. It has a profile similar to the one very fine and fine granular structure; hard, described as representative of the series, but the upper firm, sticky and plastic; many roots ; many 12 to 24 inches is recently deposited silt loam very fine pores; neutral; abrupt smooth alluvium. boundary. Included with this soil in mapping are soils that have a A12-4 to 13 inches; dark gray (10YR 4/1) silty silty clay loam surface layer and soils that are silt loam clay loam, black (10YR 2/1) moist; strong to a depth of 60 inches. very fine and medium subangular blocky Runoff is very slow, and there is little or no hazard of structure; hard, firm, sticky and plastic; erosion. This soil is subject to flooding during winter and common roots ; many fine pores; neutral; spring. A seasonally high water table is at a depth of 2 to clear wavy boundary. 3 feet. This soil is used mainly for wheat, barley, legumes, grass, range, and wildlife habitat. Capability unit IIIw- 1; Wet Meadow range site.

Kuhl Series complex consists of 50 percent Kuhl cobbly silt loam The Kuhl series consists of gently sloping to very and 30 percent Alpowa cobbly silt loam. The Alpowa soil is steep, well drained, cobbly soils underlain by basalt at a on north-facing side slopes, and the Kuhl soil is on depth of 10 to 20 inches. The soils formed in loess and south-facing side slopes. The Kuhl soil has the profile some volcanic ash that contained alluvium and residuum described as representative for its series, and the weathered from basalt. They are on side slopes of the Alpowa has one similar to the one described as repre- Snake River and of drainageways and are in channeled sentative for its series. scablands in the southern and western parts of the county. Included with these soils in mapping are areas of Elevation is 800 to 2,600 feet. The native vegetation is soils that are less than 10 inches or more than 20 inches mainly bluebunch wheatgrass and Sandberg bluegrass. deep over basalt, stony or very stony soils, and Rock The annual precipitation is 12 to 15 inches. The frost- outcrop. Included areas make up about 20 percent of the free season is 140 to 150 days. mapped acreage. In a representative profile the surface layer is dark Runoff is rapid or very rapid, and the erosion hazard is grayish brown cobbly silt loam and grayish brown high or very high. gravelly silt loam about 10 inches thick. The subsoil, to These soils are used mainly for range and for wild- a depth of 16 inches, is yellowish brown gravelly silt life habitat. Capability unit VIIs-1; Kuhl part in Shal- loam underlain by basalt. low range site (S-2), Alpowa part in Loamy range site (L- Kuhl soils have moderate permeability. The available 2). water capacity is low. Roots penetrate to bedrock. Kuhl 46-Kuhl-Anders complex, 3 to 15 percent slopes. These soils are used mainly for range and for wildlife habitat. gently sloping to strongly sloping soils are in channeled They are mapped only in complex with Alpowa, scablands. This complex consists of 40 percent Kuhl Anders, and Asotin soils. cobbly silt loam that has slopes of 3 to 15 percent and Representative profile of Kuhl cobbly silt loam in an 30 percent Anders silt loam, 3 to 15 percent slopes. area of Kuhl-Alpowa complex, 30 to 65 percent slopes, The topography is mounded, and the mounds are 10 to in an area of grassland, 2,400 feet west and 1,900 feet 30 feet in diameter and are generally 10 to 30 feet apart. south of the northeast corner of sec. 11, T. 14 N., R. 40 The tops of the mounds are generally 1 to 4 feet higher E.: than the surrounding areas. The Anders soil is on the A11-0 to 6 inches; dark grayish brown (10YR mounds, and the Kuhl soil is between the mounds. 4/2) cobbly silt loam, very dark brown Included with these soils in mapping are areas of (10YR 2/2) moist; weak fine granular soils that are less than 10 inches deep, silt loams that structure ; slightly hard, friable, slightly are 20 to 40 inches deep to gravel and cobbles, soils sticky and slightly plastic; many roots; 15 that are 40 to more than 60 inches deep, stony or very percent angular basalt fragments; neutral; stony soils, silt loams, and Rock outcrop. Included areas abrupt wavy boundary. make up about 30 percent of the mapped acreage. A12-6 to 10 inches; grayish brown (10YR 5/2) Runoff is slow to medium, and the erosion hazard is gravelly silt loam, very dark grayish slight or moderate. These soils are used mainly for brown (10YR 3/2) moist; weak blocky range and for wildlife habitat. Capability unit VIIs-1; structure; slightly hard, friable, slightly Kuhl part in Shallow range site (S-2), Anders part in sticky and slightly plastic; common fine Loamy range site (L-2). and very fine roots; many fine tubular 47-Kuhl-Asotin complex, 7 to 30 percent slopes. These pores; 15 percent angular basalt frag- strongly sloping to moderately steep soils are on side ments ; neutral. slopes. This complex consists of 50 percent Kuhl cobbly B2-10 to 16 inches; yellowish brown (10YR 5/4) silt loam that has slopes of 7 to 30 percent and 25 gravelly silt loam, dark yellowish brown percent Asotin silt loam, 7 to 25 percent slopes. The tops (10YR 3/4) moist; moderate medium of mounds are 1 to 4 feet higher than the surrounding subangular blocky structure ; slightly hard, areas, and the mounds are 6 to more than 12 feet in friable, sticky and plastic; common fine and diameter and are generally 5 to 20 feet apart. The very fine roots; many very fine tubular stringers are about 1 to 4 feet high, are 6 to 25 feet pores; 25 percent angular basalt wide, and are more than 100 feet long. The Kuhl soil fragments; neutral. is in the areas between the mounds and stringers. The R-16 inches ; basalt. Asotin soil is free of cobbles and is on mounds and stringers. Basalt is at a depth of 10 to 20 inches. The control Included with these soils in mapping are areas of section, between a depth of 10 inches and bedrock, is 15 soils that are less than 10 inches deep to basalt; soils to 35 percent gravel, cobbles, or stones. The profile is that are 40 to 60 inches deep to basalt and that are neutral to mildly alkaline, and in places there are lime cobbly, stony, or very stony ; and Rock outcrop. In- accumulations on the basalt. cluded areas make up about 25 percent of the mapped The A horizon has value of 4 or 5 when dry and 2 or acreage. 3 moist. It is cobbly loam or cobbly silt loam. The B2 Runoff is medium to rapid, and the hazard of erosion horizon has value of 5 or 6 when dry and 3 or 4 when is moderate to high. moist, and it has chroma of 3 or 4 when dry or moist. It These soils are used mainly for range and wildlife is loam or silt loam and is gravelly. habitat. Capability unit VIIs-1; Kuhl part in Shallow 45-Kuhl-Alpowa complex, 30 to 65 percent slopes. These steep and very steep soils are on side slopes. This

C2sica-19 to 25 inches; pale brown (10YR 6/3) range site (S-2), Asotin part in Loamy range site (L-2). silt loam, brown (10YR 5/3) moist; mas- sive; slightly hard, friable, slightly sticky Lance Series and slightly plastic; many roots; many fine and very fine pores; common lime-silica The Lance series consists of gently sloping to steep, cemented nodules 1 inch in diameter; 2 well drained, severely eroded soils that formed in cal- percent lime-silica cemented fragments ; careous loess. The soils are on south-facing side slopes lime in pores and as coatings on peds; and ridgetops on uplands in the central part of the strongly effervescent; moderately alkaline; county. Elevation is 1,600 to 2,600 feet. The native clear wavy boundary. vegetation is mainly Idaho fescue and bluebunch C3sica-25 to 30 inches; very pale brown (10YR wheatgrass. The annual precipitation is 15 to 18 7/3) weakly lime-cemented brittle silt inches. The frost-free season is 130 to 140 days. loam, brown (10YR 5/3) moist; massive ; In a representative profile the surface laver is about 13 hard, firm, slightly sticky and slightly inches thick. The upper part is about 8 inches of light plastic; few roots; many fine and very fine brownish gray silt loam that is 10 percent white, lime- pores; 10 percent lime-silica cemented silica cemented fragments. The lower part is about 5 fragments ; lenses of lime-silica cemented inches of brown silt loam that is 2 percent white, lime-silica material 1/16 to 1/8 inch thick; lime coatings cemented fragments. The underlying material, to a depth on peds and in pores; strongly effervescent; of 25 inches, is brown and pale brown silt loam that is strongly alkaline; clear wavy boundary. 2 percent white, lime-silica cemented fragments. C4sica-30 to 42 inches ; very pale brown (10YR 7/3) Below this, to a depth of 60 inches, it is pale brown silt loam, brown (10YR 5/3) moist; and very pale brown silt loam that is 10 percent white, massive; hard, firm (brittle), slightly sticky lime-silica cemented fragments and has white, lime-silica and slightly plastic; few roots; many fine cemented lenses 1/16 to 1/8 inch thick. and very fine pores; 10 percent lime- Lance soils have moderately slow permeability. The silica cemented fragments; strongly available water capacity is moderately high. Root pene- effervescent; strongly alkaline; clear wavy tration is limited by the strongly cemented lenses, but a boundary. few roots penetrate to a depth of 60 inches or more. C5sica-42 to 52 inches; very pale brown (10YR Lance soils are used mainly for grass, alfalfa, and 7/3) silt loam, brown (10YR 5/3) moist; range. massive; hard, firm, slightly sticky and Representative profile of Lance silt loam, 5 to 25 slightly plastic; few roots; many fine and percent slopes, in a cultivated area, 3,600 feet north very fine pores; lenses of lime-silica and 500 feet west of the southeast corner of sec. 9, T. cemented material 1/16 to 1/8 inch thick; 10 19 N., R. 39 E.: percent lime-silica cemented fragments; Ap-0 to 8 inches; light brownish gray (10YR strongly effervescent; strongly alkaline ; 6/2) silt loam, dark grayish brown (10YR clear wavy boundary. 4/2) moist; weak fine and medium granular C6sica-52 to 60 inches; pale brown (10YR 6/3) silt structure; slightly hard, very friable, loam, brown (10YR 5/3) moist; massive; slightly sticky and slightly plastic; many slightly hard, friable, slightly sticky and roots; 10 percent lime-silica cemented slightly plastic; few roots; many fine and fragments ; strongly effervescent; strongly very fine pores; lime in pores and in root alkaline; abrupt smooth boundary. channels; strongly effervescent; strongly A3-8 to 13 inches; brown (10YR 5/3) silt loam, alkaline. dark brown (10YR 4/3) moist; weak coarse prismatic structure parting to weak The profile is generally calcareous in all parts but in fine and medium subangular blocky; places is noncalcareous in the upper 7 inches. Lime- slightly hard, friable, slightly sticky and silica cemented fragments or discontinuous layers occur slightly plastic; many roots ; many fine randomly throughout. The control section, between depths pores; 2 percent lime-silica cemented of 10 and 40 inches, is 20 to 27 percent clay. The A fragments ; slightly effervescent; horizon has value of 5 to 7 when dry and 3 or 4 when moderately alkaline; clear wavy boundary. moist, and it has chroma of 2 or 3 when dry or moist. The Clsica-13 to 19 inches; brown (10YR 5/3) silt C horizon has value of 5 to 7 when dry and 3 to 5 when loam, dark brown (10YR 4/3) moist; moist, and it has chroma of 2 or 3 when dry or moist. weak medium prismatic structure parting 48-Lance silt loam, 5 to 25 percent slopes. This to weak fine and medium subangular blocky; gently sloping to moderately steep, severely eroded slightly hard, friable, slightly sticky and soil is on uplands. It has the profile described as repre slightly plastic; many roots ; many fine sentative of the series. tubular pores; 2 percent lime-silica Included with this soil in mapping are small areas cemented fragments; slightly effervescent; of soils that have lime below a depth of 20 inches and moderately alkaline; clear wavy boundary. a silt loam that is 60 inches deep and does not contain lime. Runoff is medium, and the erosion hazard is moderate.

This soil is used mainly for wheat, grass, and alfalfa. slightly hard, friable, slightly sticky and Capability unit VIe-2. slightly plastic; many roots ; many fine 49-Lance silt loam, 25 to 40 percent slopes. This pores; many thin clay films; gray (10YR moderately steep and steep, severely eroded soil is on 7/2) coatings on peds; neutral; clear uplands. It has a profile similar to the one described as irregular boundary. representative of the series, but there are more lime- B21t-21 to 32 inches; yellowish brown (10YR silica cemented fragments in the surface layer. 5/4) silt loam, dark yellowish brown Included with this soil in mapping are areas of soils (10YR 3/4) moist; weak medium that contain lime below a depth of 20 inches and a prismatic structure parting to weak fine silt loam that is 60 inches deep and that does not angular blocky; hard, friable, sticky and contain lime. plastic; common roots; many fine pores; Runoff is rapid, and the hazard of erosion is high. This continuous thin clay films on vertical ped soil is used mainly for wheat, grass, alfalfa, faces; few faint gray (10YR 7/2) and range. Capability unit VIe-2; Loamy range site coatings on peds; mildly alkaline; clear (L-3). irregular boundary. B22t-32 to 42 inches; pale brown (10YR 6/3) Larkin Series silty clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic The Larkin series consists of gently sloping to very structure parting to angular blocky; hard, steep, well drained soils that formed in loess. The soils are firm, sticky and plastic; common roots ; along the drainageway of the Palouse River and buttes many fine pores; continuous thin clay films on uplands in the eastern part of the county. Elevation on peds ; few fine manganese concretions; is 1,800 to 3,000 feet. The native vegetation is mainly some organic staining; mildly alkaline; ponderosa pine, Douglas-fir, pinegrass, snowberry, and clear irregular boundary. rose. The annual precipitation is 22 to 23 inches. The B3t-42 to 60 inches ; pale brown (10YR 6/3) heavy frost-free season is 100 to 120 days. silt loam, dark brown (10YR 4/3) moist; In a representative profile the surface layer is grayish weak prismatic structure parting to brown and brown silt loam about 16 inches thick. The moderate medium subangular blocky; hard, subsoil extends to a depth of 60 inches. It is brown and friable, sticky and plastic; common roots ; yellowish brown silt loam to a depth of 32 inches. Below many fine pores; continuous thin clay films this, it is pale brown silty clay loam and heavy silt loam. on peds. Larkin soils have moderate or moderately slow per- meability. The available water capacity is high. Roots Depth to basalt bedrock ranges from 40 to more than penetrate to a depth of 60 inches or more. Larkin soils 60 inches. are used mainly for wheat, barley, peas, lentils, grass, The A horizon is 11 to 20 inches thick. It has value alfalfa, woodland, and wildlife habitat. of 4 or 5 when dry and 2 or 3 when moist. The B hori Representative profile of Larkin silt loam, 3 to 15 zon has value of 5 or 6 when dry and 3 or 4 when moist, percent slopes, in an area of woodland, 1,600 feet east and it has chroma of 3 or 4 when dry or moist. It is 24 and 1,620 feet south of the west quarter-corner of sec. to 30 percent clay. 21, T. 17 N., R. 45 E. 50-Larkin silt loam, 3 to 15 percent slopes. This A11-0 to 4 inches; grayish brown (10YR 5/2) silt gently sloping to strongly sloping soil is on uplands. It loam, very dark grayish brown (10YR has the profile described as representative of the series. 3/2) moist; weak fine granular structure; Included with this soil in mapping are areas of soils slightly hard, friable, slightly sticky and that have basalt bedrock below a depth of 40 inches slightly plastic; many roots; neutral; abrupt and soils that have a surface layer more than 20 inches smooth boundary. thick. A12-4 to 9 inches; grayish brown (10YR 5/2) silt Runoff is slow to medium, and the erosion hazard is loam, very dark grayish brown (10YR slight to moderate. 3/2) moist; weak thin platy structure; This soil is used mainly for wheat, barley, peas, slightly hard, friable, slightly sticky and lentils, grass, alfalfa, woodland, and wildlife habitat. slightly plastic; many roots; many fine Capability unit IIIe-8. pores; neutral; clear smooth boundary. 51-Larkin silt loam, 15 to 25 percent slopes. This A3-9 to 16 inches; brown (10YR 5/3) silt loam, moderately steep soil is on uplands. It has a profile dark brown (10YR 3/3) moist; weak similar to the one described as representative of the medium subangular blocky structure; series, but the surface layer is 2 to 3 inches thinner. slightly hard, friable, slightly sticky and Included with this soil in mapping are areas of soils slightly plastic; many roots; many fine that have a surface layer more than 20 inches thick pores; gray (10YR 7/2) coatings on ped and areas of soils with basalt bedrock at a depth of 40 faces; neutral; gradual wavy boundary. inches. B1t-16 to 21 inches; brown (10YR 5/3) silt loam, Runoff is medium, and the erosion hazard is mod- dark brown (10YR 3/3) moist; weak erate. medium prismatic structure parting to This soil is used mainly for wheat, barley, peas, weak very fine subangular blocky; lentils, grass, alfalfa, woodland, and wildlife habitat. Capability unit IVe-8. 52-Larkin silt loam, 25 to 40 percent slopes. This moderately steep and steep soil is on uplands. It has a profile similar to the one described as representative of the series, but the surface layer is 2 to 4 inches thinner. Included with this soil in mapping are areas of soils with basalt bedrock at a depth of 40 inches and soils that have a surface layer more than 20 inches thick. Runoff is rapid, and the erosion hazard is high. This soil is used mainly for alfalfa, grass, woodland, and wildlife habitat. Capability unit V Ie-3. 53-Larkin silt loam, 40 to 55 percent slopes. This steep and very steep soil is on uplands. It has a profile similar to the one described as representative of the series, but the surface layer is 2 to 4 inches thinner. Included with this soil in mapping are areas of soils with basalt bedrock at a depth of 40 inches, small areas of soils that have a surface layer more than 20 inches thick, and areas of Rock outcrop. Runoff is very rapid, and the erosion hazard is very high. This soil is used mainly for woodland and for wildlife habitat. Capability unit VIe-3.

Latah Series

The Latah series consists of nearly level, somewhat poorly drained soils that formed in alluvium from loess and volcanic ash. The soils are on bottom lands in the northeastern part of the county. Elevation is 1,800 to 2,800 feet. The native vegetation is mainly tufted hair- grass, sedges, and willows. The annual precipitation is 18 to 23 inches. The frost-free season is 110 to 135 days. In a representative profile the surface layer is dark grayish brown silt loam about 19 inches thick. The subsurface layer, to a depth of 30 inches, is light gray and light brownish gray silt loam. The subsoil, which extends to a depth of 60 inches, is brown silty clay loam (fig. 16). Latah soils have moderate permeability to a depth of 30 inches and very slow permeability at a depth of more than 30 inches. The available water capacity is high. Roots penetrate to a depth of 60 inches or more. Latah soils are used mainly for wheat, barley, oats, legumes, grass, range, and wildlife habitat. Representative profile of Latah silt loam, in an area of grassland, 2,600 feet south and 600 feet west of the northeast corner of sec. 7, T. 15 N., R. 46 E.: A11-0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate fine and medium granular structure ; slightly sticky and slightly plastic; many roots; many very fine pores; neutral ; abrupt smooth boundary. A12-6 to 10 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak coarse prismatic structure parting to moderate fine and medium subangular blocky; slightly Figure 16.-Profile of Latah silt loam. hard, very friable, slightly sticky and slightly plastic; many roots; many very fine pores; neutral; clear wavy friable, slightly sticky and slightly plastic; boundary. many roots; many very fine pores; A13-10 to 19 inches; dark grayish brown (10YR neutral ; clear wavy boundary. 4/2) silt loam, very dark brown (10YR A21-19 to 24 inches; light brownish gray (10YR 2/2) moist; moderate fine and medium 6/2) silt loam, dark grayish brown (10YR prismatic structure; slightly hard, very 4/ 2) moist; weak fine and medium prismatic structure; slightly hard, very

friable, slightly sticky and slightly plastic; The soils are in canyons along the drainageways of common roots; common very fine pores; the Snake and Palouse Rivers in the southeastern part neutral; clear irregular boundary. of the county. Elevation is 1,100 to 2.600 feet. The A22-24 to 30 inches; light gray (10YR 7/1) silt native vegetation is mainly Idaho fescue, bluebunch loam, gray (10YR 5/1) moist; massive; wheatgrass, hawthorne, rose, and snowberry. The an slightly hard, very friable, slightly sticky nual precipitation is 15 to 20 inches. The frost-free and slightly plastic; common roots; many season is 110 to 120 days. very fine pores; neutral; abrupt smooth In a representative profile the surface layer is about boundary. 21 inches thick. It is dark grayish brown and grayish B21t-30 to 36 inches; brown (10YR 5/3) silty brown silt loam with a few pebbles and cobbles through clay loam, dark brown (10YR 4/3) moist; out. The subsoil, to a depth of 60 inches, is brown and few fine and medium light brown (7.5YR yellowish brown cobbly silt loam. The content of peb 6/4) and light gray (2.5YR 7/2) mottles bles and cobbles increases with depth. on peds; strong fine and medium Linville soils have moderate permeability. The avail subangular blocky structure; hard, very able water capacity is high. Roots penetrate to a depth firm, sticky and plastic; some flattened of 40 to 60 inches or more. Linville soils are used mainly roots between peds and no roots in peds; for range and for wildlife habitat. common very fine pores; thick continuous Representative profile of Linville silt loam, 30 to 65 clay films on peds ; organic matter stainings percent slopes, in an area of grassland, 1,800 feet east along vertical planes; neutral; clear and 1,200 feet south of the northwest corner of sec. smooth boundary. 17, T. 13 N., R. 44 E.: B22t-36 to 60 inches; brown (10YR 5/3) silty All-0 to 4 inches ; dark grayish brown (10YR 4/2) clay loam, dark brown (10YR 4/3) moist; silt loam, very dark brown (10YR 2/2) common medium reddish yellow (7.5YR 6/6) moist; weak fine and medium granular and common medium and large light gray structure; slightly hard, friable, slightly (2.5YR 7/2) mottles on peds ; strong fine sticky and slightly plastic; many roots ; and medium subangular blocky structure; common very fine pores; few basalt pebbles hard, very firm, sticky and plastic; some and cobbles; neutral; clear wavy boundary. flattened roots between peds and no roots in A12-4 to 12 inches; dark grayish brown (10YR peds; many very fine pores; thin continuous 4/2) silt loam, very dark brown (10YR clay films on peds ; organic matter stainings 2/2) moist; weak fine and medium sub- along factures ; neutral. angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; The profile is neutral to mildly alkaline throughout. many roots; common very fine pores; few The thickness of the A1 horizon is 17 to 32 inches. basalt pebbles and cobbles; neutral; clear The A1 horizon has value of 4 or 5 when dry and 2 or wavy boundary. 3 when moist, and it has chroma of 1 or 2 when dry or A3-12 to 21 inches; grayish brown (10YR 5/2) silt moist. The A2 horizon has value of 5 to 7 when dry and loam, very dark grayish brown (10YR 4 or 5 when moist, and it has chroma of 1 or 2 when 3/2) moist; weak fine and medium dry or moist. The B horizon is silty clay loam, silty subangular blocky structure ; slightly hard, clay, or clay and is 35 to 60 percent clay. It has value of friable, slightly sticky and slightly plastic; 4 to 6 when dry and 3 to 5 when moist, and it has many roots; common very fine pores; 5 chroma of 2 or 3 when moist or dry. In places there are percent basalt pebbles and cobbles; neutral; mottles below the All horizon. The A2 and B horizons clear wavy boundary. have few very fine and fine manganese concretions in B21-21 to 29 inches; brown (10YR 5/3) cobbly places. silt loam, dark brown (10YR 3/3) moist; 54.--Latah silt loam. This nearly level soil is on bottom moderate fine and medium subangular lands. blocky structure; slightly hard, friable, Included with this soil in mapping are areas of soils that sticky and plastic; many roots; common are silt loam to a depth of 60 inches, poorly drained very fine pores; 25 percent basalt pebbles soils, and soils that are silty clay loam to a depth of 60 and cobbles; neutral; abrupt wavy inches. boundary. Runoff is very slow, and there is little or no hazard of B22-29 to 36 inches; yellowish brown (10YR 5/4) erosion. Low areas are subject to overflow. A sea- cobbly silt loam; dark yellowish brown sonally high water table is at a depth of 1/2 foot to 2 1/2 (10YR 3/4) moist; moderate fine and feet. medium subangular blocky structure; hard, This soil is used mainly for wheat, barley, oats, firm, sticky and plastic; common roots; legumes, grass, range, and wildlife habitat. Capability common very fine pores; few thin patchy unit IIIw-l ; Wet Meadow range site. clay films on peds ; 25 percent basalt pebbles and cobbles; neutral; clear wavy Linville Series boundary. B3-36 to 60 inches; yellowish brown (10YR 5/4) The Linville series consists of steep to very steep, cobbly silt loam, brown (10YR 4/3) well drained soils that formed in loess and small amounts of volcanic ash and residuum from basalt.

moist; weak fine and medium subangular substratum, to a depth of 28 inches, is brown sandy blocky structure; hard, firm, sticky and loam. Below this, to a depth of 60 inches, it is loose, plastic; few roots; few very fine pores; coarse and very coarse basalt sand. thin patchy clay films and lime coatings on Magallon soils have moderate and moderately rapid undersides of some gravel and cobbles; 35 permeability to a depth of 20 to 40 inches and rapid percent basalt pebbles and cobbles; permeability at a depth of more than 40 inches. The moderately alkaline. available water capacity is moderate to moderately high. Roots penetrate to a depth of 60 inches or more. Depth to bedrock is 40 to 60 inches or more. The Magallon soils are used mainly for wheat, range, and profile is neutral to moderately alkaline throughout. wildlife habitat. Thickness of the A horizon is 20 to 30 inches. The Representative profile of Magallon loam, 3 to 20 A horizon has value of 2 or 3 when moist and 4 or 5 percent slopes, in an area of grassland, 400 feet west when dry, and it has chroma of 1 or 2 when moist or and 2,400 feet north of the center of sec. 33, T. 13 N., dry. It is 5 to 35 percent angular gravel or cobbles. R. 37 E.: The B horizon has value of 3 or 4 when moist and 5 or 6 A1-0 to 6 inches; grayish brown (10YR 5/2) when dry. It is 15 to 35 percent angular basalt pebbles loam, very dark grayish brown (10YR and cobbles. 3/2) moist; weak thick platy structure 55-Linville silt loam, 30 to 65 percent slopes. This parting to weak fine granular; soft, very steep to very steep soil is on north-facing sides of friable, slightly sticky and slightly plastic; canyons. many roots; many fine pores; mildly Included with this soil in mapping are areas of soils alkaline; clear smooth boundary. that have basalt at a depth of less than 40 inches, B2-6 to 12 inches; brown (10YR 5/3) fine sandy cobbly and stony soils, and Rock outcrop. loam, dark brown (10YR 3/3) moist; Runoff is rapid to very rapid, and the erosion hazard is weak coarse subangular blocky structure; high to very high. soft, very friable, nonsticky and This soil is used mainly for range and for wildlife nonplastic ; common roots; many fine pores; habitat. Capability unit VIIe-1; North exposure range mildly alkaline; clear smooth boundary. site (N-2). C1-12 to 28 inches ; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; Lithic Xerorthents massive; soft, very friable, nonsticky and nonplastic; common roots; many fine Lithic Xerorthents are nearly level to moderately pores; moderately alkaline; abrupt smooth steep, shallow and very shallow, well drained soils boundary. underlain by basalt. They formed in material weathered IIC2-28 to 60 inches; coarse and very coarse from basalt and loess. The soils are on basalt basalt sand ; strongly alkaline. plateaus, on plateau breaks, and in channeled scablands. Elevation is 600 to 2,600 feet. The native vegetation is Depth to coarse and very coarse sand is 20 to 40 mainly bluebunch wheatgrass and Sandberg bluegrass. inches. The part of the control section above the sand The annual precipitation is 12 to 18 inches. The frost- averages less than 50 percent fine and coarse sand. free season is 100 to 150 days. The A horizon is 6 to 9 inches thick and is sandy In most places the soil is gravelly, very gravelly, or loam, loam, or silt loam. It has value of 4 or 5 when cobbly sandy loam, loam, or silt loam. Depth to basalt is 5 dry and 2 or 3 when moist. The B2 horizon has value to 12 inches. of 4 or 5 when dry and 2 or 3 when moist. The C hori Lithic Xerorthents have moderate permeability. The zon has value of 5 or 6 when dry and 3 or 4 when moist. available water capacity is low. Roots penetrate to 56-Magallon loam, 3 to 20 percent slopes. This bedrock. Lithic Xerorthents are used mainly for wildlife gently sloping to moderately steep soil is on terraces. habitat and for limited grazing early in spring. They It has the profile described as representative of the are mapped only in complex with Rock outcrop. series. Included with this soil in mapping are areas of soils Magallon Series with a coarse sandy loam surface layer and silt loam underlain by sand, gravel, and cobbles at a depth of 20 to The Magallon series consists of gently sloping to 40 inches. steep, somewhat excessively drained soils underlain by Runoff is slow to medium, and the erosion hazard is loose, coarse and very coarse basalt sand at a depth of slight or moderate. 20 to 40 inches. The soils formed in glacial outwash This soil is used mainly for wheat, range, and wildlife derived from reworked loess, basalt, and some volcanic habitat. Capability unit IVe-7; Loamy range site (L-2). ash. They are on terraces of channeled scablands and 57-Magallon sandy loam, 20 to 40 percent slopes. This along major drainageways in the southwestern part of strongly sloping to steep soil is on terraces. It has a the county. Elevation is 500 to 1,500 feet. The native profile similar to the one described as representative of vegetation is mainly bluebunch wheatgrass, Thurber the series, but the surface layer is sandy loam. needlegrass, and Sandberg wheatgrass. The annual Included with this soil in mapping are areas of soils with precipitation is 11 to 12 inches. The frost-free season a loam surface layer and silt loams underlain by loose is 145 to 155 days. sand, gravel, and cobbles at a depth of 20 to 40 inches. In a representative profile the surface layer is grayish brown loam about 6 inches thick. The subsoil, to a depth of 12 inches, is brown fine sandy loam. The

Runoff is rapid, and the erosion hazard is high. canic ash. The soils are on ridgetops and south-facing This soil is used mainly for range and for wildlife slopes on uplands in the northeastern part of the habitat. Capability unit VIe-1 ; Sandy Loam range site. county. Elevation is 2,000 to 3,000 feet. The native vegetation is mainly Idaho fescue, bluebunch wheatgrass, Mondovi Series and snowberry. The annual precipitation is 18 to 23 inches. The frost-free season is 110 to 130 days. The Mondovi series consists of nearly level, well In a representative profile the surface layer is dark drained soils that formed in alluvium from loess and grayish brown silt loam about 9 inches thick. The next some volcanic ash. The soils are on bottom lands and layer, to a depth of 18 inches, is dark brown silty clay alluvial fans in the central part of the county. Elevation loam. The subsoil extends to a depth of 60 inches. It is is 1,600 to 2,500 feet. The native vegetation is mainly yellowish brown silty clay loam to a depth of 47 inches. bluebunch wheatgrass, Idaho fescue, and giant wildrye. The Below this, it is light yellowish brown silt loam. annual precipitation is 15 to 18 inches. The frost-free Naff soils have moderately slow permeability. The season is 130 to 140 days. available water capacity is high. Roots penetrate to a In a representative profile the soil is dark grayish depth of 60 inches or more. Naff soils are used mainly brown silt loam to a depth of 60 inches. for wheat, barley, peas, lentils, grass, and alfalfa. Mondovi soils have moderate permeability. The Representative profile of Naff silt loam, 7 to 25 available water capacity is high. Roots penetrate to a percent slopes, in a cultivated area, in the NE1/4 of sec. depth of 60 inches or more. Mondovi soils are used 26, T. 16 N., R. 44 E., 300 feet northwest of County mainly for wheat, barley, and wildlife habitat. Road No. 500 Representative profile of Mondovi silt loam, in a Ap-0 to 9 inches; dark grayish brown (10YR cultivated area, 2,500 feet north and 2,400 feet west of the 4/2) silt loam, very dark brown (10YR southeast corner of sec. 5, T. 16 N., R. 42 E.: 2/2) moist; moderate fine granular Ap-0 to 10 inches; dark grayish brown (10YR structure; slightly hard, friable, slightly 4/2) silt loam, very dark brown (10YR sticky and slightly plastic; many fine and 2/2) moist; weak fine granular structure; very fine roots; slightly acid; abrupt slightly hard, friable, slightly sticky smooth boundary. and slightly plastic; many fine roots; AB-9 to 18 inches; dark brown (10YR 4/3) silty mildly alkaline; abrupt smooth boundary. clay loam, dark brown (10YR 3/3) crushed A11-10 to 33 inches; dark grayish brown (10YR ped faces, very dark brown (10YR 2/2) 4/2) silt loam, very dark brown (10YR moist; weak coarse prismatic structure; 2/2) moist; massive; slightly hard, hard, friable, slightly sticky and plastic; friable, slightly sticky and slightly plastic; many fine and very fine roots; common many fine and very fine roots; very few fine fine pores; neutral ; clear wavy boundary. tubular pores; mildly alkaline; abrupt B21t-18 to 33 inches; yellowish brown (10YR smooth boundary. 5/4) silty clay loam, dark brown (10YR A12-33 to 60 inches; dark grayish brown (10YR 4/3) moist; ped faces, dark brown (7.5YR 4/2) silt loam, very dark brown (10YR 3/3) moist; moderate medium prismatic 2/2) moist; massive; slightly hard, friable, structure parting to strong fine angular slightly sticky and slightly plastic; common blocky; very hard, very firm, sticky and fine and very fine roots; mildly alkaline. plastic; common fine and very fine roots; many micropores and common very fine The control section, between depths of 10 and 40 pores; thin continuous clay films on peds ; inches, is less than 18 percent clay. neutral ; gradual wavy boundary. The A horizon has value of 4 when dry and 2 when moist B22t-33 to 47 inches; yellowish brown (10YR and chroma of 1 or 2 when dry or moist. It is neutral to 5/4) silty clay loam, dark brown (10YR mildly alkaline. 4/3) moist; ped faces, dark brown (7.5YR 58-Mondovi silt loam. This nearly level soil is on 3/3) ; moderate fine angular blocky bottom lands and alluvial fans. structure; very hard, very firm, slightly Included with this soil in mapping are areas of soils sticky and plastic; few fine roots; many that have bedrock at a depth of 20 to 40 inches and micropores and many fine pores; continuous soils that are moderately alkaline to a depth of 60 thin clay films on peds; neutral; gradual inches. wavy boundary. Runoff is very slow, and there is little or no hazard of B3-47 to 60 inches; light yellowish brown (10YR erosion. In places this soil is subject to flooding during 6/4) silt loam, dark yellowish brown winter and spring. (10YR 4/3) moist; weak prismatic This soil is used mainly for wheat, barley, and wildlife structure parting to moderate fine angular habitat. Capability unit IIc-1. blocky; hard, firm, slightly sticky and slightly plastic; few fine roots; common fine Naff Series pores and many micro tubular pores; thin clay films on peds; few 2-millimeter iron- The Naff series consists of gently sloping to steep, manganese concretions ; neutral. well drained soils that formed in loess and some vol-

The A horizon is 9 to 18 inches thick. It has value of 4 In a representative profile the surface layer is gray or 5 when dry and 2 or 3 when moist, and it has ish brown silt loam and loam about 39 inches thick. chroma of 2. The AB horizon has value of 4 or 5 when dry The underlying material, to a depth of 52 inches, is and 2 or 3 when moist, and it has chroma of 2 or 3. It is light brownish gray fine sandy loam. Below this, to a heavy silt loam or silty clay loam. The B2t horizon has depth of 60 inches, it is light brownish gray very fine hue of 7.5YR or 10YR, value of 4 or 5 when dry and 3 sandy loam. or 4 when moist, and chroma of 3 or 4. It has continuous Narcisse soils have moderate permeability. The avail thin to thick clay films. The B3 horizon has value of 5 able water capacity is high. Roots penetrate to a depth or 6 when dry and 4 or 5 when moist, and it has chroma of 60 inches or more. Narcisse soils are used mainly of 3 or 4. It is silt loam or silty clay loam and is slightly for wheat, barley, oats, legumes, grass, woodland, and acid to mildly alkaline. wildlife habitat. 59-Naff silt loam, 7 to 25 percent slopes. This strongly Representative profile of Narcisse silt loam, in an sloping to moderately steep soil is on ridgetops and area of grassland, 2,800 feet east and 1,400 feet north south-facing side slopes. It has the profile described of the southwest corner of sec. 21, T. 17 N., R. 45 E.: as representative of the series. A11-0 to 5 inches; grayish brown (10YR 5/2) Included with this soil in mapping are areas of soils that silt loam, very dark brown (10YR 2/2) are silt loam to a depth of 60 inches, areas of soils that moist; weak fine granular structure; have a silty clay loam surface layer, and small areas slightly hard, friable, slightly sticky and of Naff soils that have slopes of less than 7 percent. slightly plastic; many fine roots; neutral; Runoff is medium, and the erosion hazard is abrupt smooth boundary. moderate. A12-5 to 19 inches; grayish brown (10YR 5/2) This soil is used mainly for wheat, barley, peas, loam, very dark brown (10YR 2/2) moist; lentils, grass, and alfalfa. Capability unit IIIe-5. weak medium subangular blocky structure; 60-Naff silt loam, 25 to 40 percent slopes. This slightly hard, friable, slightly sticky and moderately steep to steep soil is on south-facing side slightly plastic; many roots; common fine slopes. It has a profile similar to the one described as pores; neutral; clear wavy boundary. representative of the series, but the surface layer is 2 A13-19 to 39 inches; grayish brown (10YR 5/2) to 3 inches thinner. loam, very dark grayish brown (10YR Included with this soil in mapping are areas of soils 3/2) moist; massive; slightly hard, that are silt loam to a depth of 60 inches and small friable, slightly sticky and slightly plastic; areas of soils that have a silty clay loam surface layer. many roots; common fine and medium Runoff is rapid, and the erosion hazard is high. pores; u-inch sand lenses; neutral; clear This soil is used mainly for wheat, barley, peas, wavy boundary. lentils, grass, and alfalfa. Capability unit IVe-5. C1-39 to 52 inches; light brownish gray (10YR 61-Naff-Garfield complex, 3 to 25 percent slopes. 6/2) fine sandy loam, dark grayish brown These gently sloping to moderately steep soils are on (10YR 4/2) moist; few fine yellowish ridgetops and south-facing slopes. This complex consists brown (10YR 5/6) mottles; massive; soft, of 55 percent Naff silt loam, 7 to 25 percent slopes, and 35 very friable, nonsticky and nonplastic ; percent Garfield silty clay loam, 3 to 25 percent slopes. many roots ; common fine tubular pores; The Garfield soil is on ridgetops and knobs, and the Naff neutral; clear wavy boundary. soil is on south-facing slopes. C2-52 to 60 inches; light brownish gray (10YR Included with these soils in mapping are areas of 6/2) very fine sandy loam, grayish brown soils that are silt loam to a depth of 60 inches, small (10YR 4/2) moist; massive; soft, very areas of soils that have an abrupt silty clay loam or friable, nonsticky and nonplastic; common silty clay layer at a depth of 20 to 40 inches, and areas roots; many fine pores; neutral. of Naff and Garfield soils that have slopes of more than 25 percent. The control section, between depths of 10 and 40 Runoff is slow to medium, and the erosion hazard is inches, is loam, silt loam, fine sandy loam, sandy loam, or slight to moderate. very fine sandy loam. Reaction is neutral to slightly These soils are used mainly for wheat, barley, peas, acid. lentils, grass, and alfalfa. Capability unit IVe-10. Thickness of the A horizon is 20 to 40 inches or more. The A horizon has value of 4 or 5 when dry and 2 or 3 Narcisse Series when moist, and it has chroma of 1 or 2 when dry or moist. The C horizon has value of 6 or 7 when dry and 3 or 4 The Narcisse series consists of nearly level, when moist, and it has chroma of 2 to 4 when dry or moist. moderately well drained soils that formed in alluvium It is loam, silt loam, sandy loam, very fine sandy loam, from loess, volcanic ash, and weathered metasediment and or fine sandy loam. A few 1/8- to 1/4-inch lenses of sand basalt. The soils are on bottom lands along and gravel are in the C horizon. drainageways of the Palouse River in the central and 62-Narcisse silt loam. This nearly level soil is on eastern part of the county. Elevation is 1,400 to 2,500 bottom lands. feet. The native vegetation is mainly ponderosa pine, Included with this soil in mapping are areas of soils that hawthorne, giant wildrye, and other shrubs and grasses. are silt loam to a depth of 60 inches and soils that are 20 The annual precipitation is 16 to 23 inches. The frost- to 40 inches deep to basalt or gravel and cobbles. free season is 100 to 135 days. Runoff is very slow, and there is little or no hazard

are moderately alkaline to strongly alkaline in the sur- of erosion. This soil is subject to flooding during winter face layer, and soils that have lime in the subsoil. and spring. A seasonally high water table is at a depth Runoff is very slow, and there is little or no hazard of of 3 to 5 feet. erosion. Areas of this soil are subject to flooding This soil is used mainly for wheat, barley, oats, during winter and spring. legumes, grass, woodland, and wildlife habitat. Capability This soil is used mainly for wheat, barley, and wildlife unit IIIw-2. habitat. Capability unit IIc-1.

Onyx Series Palouse Series

The Onyx series consists of nearly level, well drained The Palouse series consists of gently sloping to very soils that formed in alluvium from loess and some steep, well drained soils that formed in loess that volcanic ash. The soils are on bottom lands along contained some volcanic ash in the upper part. These drainageways and alluvial fans in the southwestern soils are in the eastern part of the county. Elevation is part of the county. Elevation is 600 to 2,000 feet. The 2,000 to 3,000 feet. The native vegetation is mainly native vegetation is mainly bluebunch wheatgrass, Idaho fescue, bluebunch wheatgrass, ninebark, and Sandberg bluegrass, and giant wildrye. The annual snowberry. The annual precipitation is 18 to 23 inches. precipitation is 12 to 15 inches. The frost-free season The frost-free season is 110 to 130 days. is 140 to 150 days. In a representative profile the surface layer is dark In a representative profile the surface layer is dark grayish brown and grayish brown silt loam about 24 grayish brown and grayish brown silt loam about 36 inches thick. The subsoil is pale brown silt loam that inches thick. The next layer, which extends to a depth extends to a depth of 60 inches. of 60 inches, is brown silt loam. Palouse soils have moderate permeability. The avail Onyx soils have moderate permeability. The avail able water capacity is high. Roots penetrate to a depth able water capacity is high. Roots penetrate to a depth of 60 inches or more. Palouse soils are used mainly for of 60 inches or more. Onyx soils are used mainly for wheat, barley, peas, lentils, grass, alfalfa, range, and wheat, barley, and wildlife habitat. wildlife habitat. Representative profile of Onyx silt loam, in a cul- tivated area, 1,300 feet east and 100 feet north of the Representative profile of Palouse silt loam, 7 to 25 southwest corner of sec. 26, T. 15 N., R. 39 E. percent slopes, in a cultivated area, 280 feet north of a Ap-0 to 10 inches; dark grayish brown (10YR county road and 970 feet east of west boundary of sec. 4/2) silt loam, very dark brown (10YR 27, T. 14 N., R. 45 E. 2/2) moist; weak fine granular structure; Ap-0 to 7 inches; dark grayish brown (10YR slightly hard, friable, slightly sticky and 4/2) silt loam, very dark brown (10YR slightly plastic; many roots; neutral; clear 2/2) moist; moderate fine granular wavy boundary. structure; slightly hard, friable, slightly A12-10 to 21 inches ; grayish brown (10YR 5/2) sticky and slightly plastic; many fine silt loam, very dark grayish brown (10YR roots; neutral ; abrupt smooth boundary. 3/2) moist; massive; slightly hard, A12-7 to 14 inches; dark grayish brown (10YR friable, slightly sticky and slightly 4/2) silt loam, very dark brown (10YR plastic; many roots; many fine pores; 2/2) moist; weak medium granular neutral; abrupt smooth boundary. structure; slightly hard, friable, slightly A13-21 to 36 inches; grayish brown (10YR 5/2) sticky and slightly plastic; many fine silt loam, very dark grayish brown roots; many fine pores; neutral; clear wavy (10YR 3/2) moist; massive; slightly hard, boundary. friable, slightly sticky and slightly plastic; A13-14 to 24 inches ; grayish brown (10YR 5/2) silt many roots; many fine pores; neutral; clear loam, very dark grayish brown (10YR 3/2) smooth boundary. moist; weak fine subangular blocky AC-36 to 60 inches ; brown (10YR 5/3) silt loam, structure; slightly hard, friable, slightly dark brown (10YR 3/3) moist; massive; sticky and plastic; many fine roots; many slightly hard, friable, slightly sticky and very fine pores; 20 percent of coarse pores slightly plastic; common roots; many fine and channels partially filled with dark pores; neutral. colored material from the A1 horizon; neutral; gradual wavy boundary. The control section between depths of 10 and 40 B21-24 to 40 inches; pale brown (10YR 6/3) silt inches is dominantly silt loam, but in many places loam, brown (10YR 4/3) moist; weak there are lenses less than 1 inch thick of very fine medium prismatic structure parting to sandy loam, fine sandy loam, sandy loam, or medium sand. moderate medium and fine subangular It is also 12 to 18 percent clay. The profile is neutral blocky; hard, firm, sticky and plastic; many to mildly alkaline throughout. fine roots ; many very fine pores; few thin Thickness of the A horizon is 20 to 40 inches or clay films on peds ; 5 to 10 percent of area more. occupied by wormholes partially filled with 63-Onyx silt loam. This nearly level soil is on dark colored material from the A horizon; bottom lands. neutral ; gradual wavy boundary. Included with this soil in mapping are areas of soils that are more than 60 percent volcanic ash, soils that

as representative of the series, but the surface layer is B22-40 to 60 inches; pale brown (10YR 6/3) 2 to 4 inches thinner. silt loam, brown (10YR 4/3) moist; weak Included with this soil in mapping are spots of coarse prismatic structure parting to severely eroded soils that are calcareous; areas of soils moderate very fine subangular blocky; that have a thin surface layer, on ridges and knobs ; hard, firm, sticky and plastic; few fine concave areas and areas on north-facing side slopes of roots; few fine pores, many very fine pores, soils that have a surface layer 3 feet thick or more; and many micropores ; large wormholes areas of soils that have a surface layer or subsoil of about 5 inches apart; neutral. silty clay loam; areas of soils that have a subsoil of calcareous silt loam; and areas of soils that have slopes of The A horizon is 20 to 36 inches thick. It has value more than 40 percent. of 4 or 5 when dry and 2 or 3 when moist. It is medium Runoff is rapid, and the hazard of erosion is high. acid to neutral. The B horizon has value of 5 or 6 when This soil is used mainly for wheat, barley, peas, dry and 3 or 4 when moist, and it has chroma of 3 or 4 lentils, grass, and alfalfa. Capability unit IVe-4. when dry or moist. It is silt loam or light silty clay 68-Palouse silt loam, 25 to 40 percent slopes, loam and is slightly acid or neutral. eroded. This moderately steep and steep soil is on 64-Palouse silt loam, 3 to 7 percent slopes. This gently smooth, south-facing side slopes and on a few ridges sloping soil is on uplands. It has a profile similar to and knobs on uplands. It has a profile similar to the the one described as representative of the series, but one described as representative of the series, but the the surface layer is 2 to 4 inches thicker. surface layer is 6 to 7 inches thinner. Included with this soil in mapping are areas of soils Included with this soil in mapping are areas of soils, that have a silt loam surface layer and slopes of more on ridges and knobs, that have a calcareous surface than 7 percent; areas of silty clay loams on knobs and layer ; areas of soils that have a silty clay loam surface ridges; and eroded spots, some of which are calcareous. layer; concave areas of soils that have a surface layer 2 Runoff is slow, and the hazard of erosion is slight. feet thick or more; areas of soils that have a subsoil of This soil is used mainly for wheat, barley, peas, silty clay loam or silty clay; and areas of soils that lentils, grass, and alfalfa. Capability unit IIe-3. have slopes of more than 40 percent. 65-Palouse silt loam, 7 to 25 percent slopes. This Runoff is rapid, and the hazard of erosion is high. strongly sloping and moderately steep soil is on up- This soil is used mainly for wheat, barley, alfalfa, lands. The landscape is mainly smooth and rolling, and in and grass. Capability unit VIe-2. places it is hilly. There are numerous ridges that have 69-Palouse silt loam, 40 to 55 percent slopes. This rounded tops and short side slopes. This soil has the steep and very steep soil is on uplands. The landscape is profile described as representative of the series. smooth and hilly and has numerous ridges and Included with this soil in mapping are spots of rounded knobs. This soil has a profile similar to the severely eroded soils that are calcareous; areas of soils one described as representative of the series, but the that have a thin surface layer, on tops of ridges and surface layer is 2 to 4 inches thinner. knobs; areas on north-facing side slopes and concave Included with this soil in mapping are spots of areas of soils that have a surface layer more than 2 severely eroded soils that are calcareous; areas of soils that feet thick; areas of soils that have a subsoil of silty clay have a thin surface layer, on ridges and knobs ; and loam or calcareous silt loam; and areas less than 150 areas on north-facing side slopes and concave areas where feet wide where the soils are steep and very steep. the thickness of the surface layer is 3 feet or more. Runoff is medium, and the hazard of erosion is Also included are areas of soils that have a subsoil of moderate. silty clay loam or silty clay; narrow, very steep, This soil is used mainly for wheat, barley, peas, semicircular areas, or eyebrows, of soils that have lentils, grass, and alfalfa. Capability unit IIIe-4. slopes of more than 55 percent; and areas of soils that 66-Palouse silt loam, 7 to 25 percent slopes, eroded. have slopes of less than 40 percent. This strongly sloping and moderately steep soil is Runoff is very rapid, and the hazard of erosion is mostly on convex, south-facing side slopes on uplands. It very high. has a profile similar to the one described as This soil is used mainly for range and for wildlife representative of the series, but the surface layer is 6 to habitat. Capability unit VIe-1, North exposure range 8 inches thinner. site (N-3). Included with this soil in mapping are spots, on 70-Palouse-Thatuna silt loams, 3 to 7 percent slopes. ridgetops and knobs, of severely eroded soils that have a These gently sloping soils are on uplands. This complex calcareous surface layer; areas of soils that have a consists of 50 percent Palouse silt loam, 3 to 7 percent surface layer of silty clay loam; concave areas of soils slopes, and 45 percent Thatuna silt loam, 3 to 7 percent that have a surface layer more than 3 feet thick; slopes. The Palouse soil is in convex areas, and the areas of soils that have a subsoil of silty clay loam or Thatuna soil is in concave areas. The profiles of the silty clay; and areas of soils that have slopes of more Palouse and Thatuna soils are similar to the ones than 25 percent. described as representative of their respective series, Runoff is medium, and the hazard of erosion is but the surface layer of the Palouse soil is 2 to 4 inches moderate. thicker and the surface layer of the Thatuna soil is 2 to This soil is used mainly for wheat, barley, peas, 3 inches thicker. lentils, grass, and alfalfa. Capability unit IVe-10. Included with these soils in mapping are concave 67-Palouse silt loam, 25 to 40 percent slopes. This areas of soils that have a surface layer more than 40 moderately steep and steep soil is on uplands. The land- inches thick and convex areas of soils that have a scape is smooth and hilly and has numerous ridges and knobs. This soil has a profile similar to the one described subsoil of silty clay loam or silty clay. Included areas areas of soils that have a surface layer and subsoil of make up about 5 percent of the mapped acreage. silty clay loam; areas of soils that have a subsoil of Runoff is slow, and the hazard of erosion is slight. silty clay loam or silty clay; areas of soils that have This complex is used mainly for wheat, barley, peas, slopes of more than 55 percent; and areas of soils that lentils, grass, and alfalfa. Capability unit IIe-3. have slopes of less than 40 percent. 71-Palouse-Thatuna silt loams, 7 to 25 percent slopes. Runoff is very rapid, and the hazard of erosion is These strongly sloping and moderately steep soils are very high. on north- and east-facing side slopes and on some These soils are used mainly for range and for south-facing foot slopes. This complex is 50 percent wildlife habitat. Capability unit VIe-1; North exposure Palouse silt loam, 7 to 25 percent slopes, and 45 range site (N-3). percent Thatuna silt loam, 7 to 25 percent slopes. These soils are mapped as a complex because they are so Pedigo Series intermingled that it is not practical to show them separately on the map. The Palouse soil is in convex The Pedigo series consists of nearly level, somewhat areas, and the Thatuna soil is in concave areas. poorly drained soils that formed in alluvium from loess Included with these soils in mapping are convex and some volcanic ash. The soils are on wide bottom areas of soils that are calcareous; areas of soils that lands along drainage ways in the central part of the have a thin surface layer, on tops of ridges or knobs; county. Elevation is 1,000 to 2,200 feet. The native areas of soils that have a subsoil of silty clay loam or vegetation is mainly giant wildrye and salt grass. The calcareous silt loam; areas of soils that have a surface annual precipitation is 15 to 18 inches. The frost-free layer and subsoil of silty clay loam; and areas less than season is 130 to 155 days. 150 feet wide of steep and very steep soils. Included In a representative profile the surface layer is grayish areas make up about 5 percent of the mapped acreage. brown, strongly alkaline silt loam about 36 inches thick. Runoff is medium, and the hazard of erosion is moderate. The underlying material, to a depth of 51 inches, is gray, This soil is used mainly for wheat, barley, peas, strongly alkaline silt loam. Below this, to a depth of 60 lentils, alfalfa, and grass. Capability unit IIIe-4. inches, it is gray, moderately alkaline silt loam. 72-Palouse-Thatuna silt loams, 25 to 40 percent slopes. Pedigo soils have moderate permeability. The available These moderately steep and steep soils are on north- water capacity is high. Roots penetrate to a depth of 60 and east-facing side slopes. This complex consists of 50 inches or more. Pedigo soils are used mainly for wheat, percent Palouse silt loam, 25 to 40 percent slopes, and 45 barley, legumes, grass, range, and wildlife habitat. percent Thatuna silt loam, 25 to 40 percent slopes. Representative profile of Pedigo silt loam, in an area These soils are mapped as a complex because they are of grass, 800 feet south and 1,500 feet east of the so intermingled that it is not practical to show them northwest corner of sec. 35, T. 17 N., R. 41 E.: separately on the map. The Palouse soil is in convex Ap-0 to 7 inches; grayish brown (10YR 5/2) areas, and the Thatuna soil is in concave areas. The silt loam, very dark brown (10YR 2/2) profiles of the Palouse and Thatuna soils are similar to moist; weak fine and medium subangular the ones described as representative of their respective blocky structure; slightly hard, friable, series, but the surface layer of the Palouse soil is 2 to slightly sticky and slightly plastic; many 4 inches thinner and the surface layer of the Thatuna roots; many fine pores; slightly efferves- soil is 4 to 5 inches thicker. cent; strongly alkaline; abrupt smooth Included with these soils in mapping are areas of boundary. calcareous soils that have a thin surface layer, on A12-7 to 24 inches; grayish brown .(10YR 5/2) silt ridges and knobs; areas of soils that have a subsoil of loam, very dark brown (10YR 2/2) moist; silty clay loam; areas of soils that have a surface layer weak fine and medium platy structure ; and subsoil of silty clay loam; and semicircular areas, or slightly hard, friable, slightly sticky and eyebrows, less than 1.50 feet wide of soils that have slightly plastic; many roots; many fine slopes of more than 40 percent. Included areas make pores; strongly effervescent ; strongly up about 5 percent of the mapped acreage. alkaline; clear wavy boundary. Runoff is rapid, and the hazard of erosion is high. A13-24 to 36 inches; grayish brown (10YR 5/2) This soil is used mainly for wheat, barley, peas, silt loam, very dark grayish brown (10YR lentils, alfalfa, and grass. Capability unit IVe-4. 3/2) moist; weak coarse and medium 73-Palouse-Thatuna silt loams, 40 to 55 percent slopes. prismatic structure; slightly hard, friable, These steep to very steep soils are on north- and east- slightly sticky and slightly plastic; facing side slopes. This complex is 50 percent Palouse common roots ; few fine pores; strongly silt loam, 40 to 55 percent slopes, and 45 percent effervescent ; strongly alkaline ; clear wavy Thatuna silt loam, 40 to 55 percent slopes. These boundary. soils are mapped as a complex because they are so C1-36 to 51 inches; gray (10YR 5/1) silt loam, intermingled that it is not practical to show them dark gray (10YR 4/1) moist; weak coarse separately on the map. The Palouse soil is in convex prismatic structure ; slightly hard, friable, areas, and the Thatuna soil is in concave areas. The slightly sticky and slightly plastic; few Palouse soil has a profile similar to the one described as roots; slightly effervescent; strongly representative of the series, but the surface layer is 2 alkaline; clear wavy boundary. to 4 inches thinner. C2-51 to 60 inches; gray (10YR 6/1) silt loam, Included with these soils in mapping are convex

calcareous silt loam. The substratum, to a depth of dark grayish brown (10YR 4/2) moist; about 60 inches, is light yellowish brown, calcareous massive; slightly hard, friable, slightly silt loam. sticky and slightly plastic; few roots; Reardan soils have moderate permeability to a depth slightly effervescent ; moderately alkaline. of 15 inches and slow permeability at a depth of more The control section, between depths of 10 and 40 than 15 inches. The available water capacity is high. inches, is 10 to 18 percent clay. Reaction is strongly Roots penetrate to a depth of 60 inches or more. Rear alkaline in the A horizon and very strongly alkaline to dan soils are used mainly for wheat, barley, and peas. mildly alkaline in the C horizon. Salinity is slight. Representative profile of Reardan silt loam, 3 to 15 Thickness of the A horizon is 24 to 40 inches. The A percent slopes, in a cultivated area, 1,600 feet south horizon has value of 2 or 3 when moist and 4 or 5 when and 2,745 feet east of the northwest corner of sec. 11, dry, and it has chroma of 2 or 3 when dry or moist. The C horizon has hue of 10YR to 2.5Y, value of 3 or 4 when moist T. 19 N., R. 40 E.: and 5 or 6 when dry, and chroma of 1 to 3. In places, Ap-0 to 8 inches; dark grayish brown (10YR there is a cemented hardpan at a depth of 40 to 60 inches. 4/2) silt loam, very dark brown (10YR 74-Pedigo silt loam. This nearly level soil is on 2/2) moist; moderate fine and medium bottom lands along drainageways. It has the profile granular structure; slightly hard, friable, described as representative of the series. slightly sticky and slightly plastic; many Included with this soil in mapping are areas of roots; few fine pores ; neutral ; abrupt poorly drained soils, areas of soils that have a weakly smooth boundary. cemented layer at a depth of 40 inches, areas of soils A1-8 to 13 inches; grayish brown (10YR 5/2) silt that are moderately alkaline, and spots of saline-alkali loam, very dark grayish brown (10YR 3/2) soils. moist; moderate medium and coarse Runoff is very slow, and there is little or no hazard of subangular blocky structure; slightly hard, erosion. This soil is subject to flooding during winter and friable, slightly sticky and slightly spring. A seasonally high water table is at a depth of 2 plastic; many roots; many fine and 1/2 to 5 feet. medium pores; neutral; clear wavy This soil is used mainly for wheat, barley, legumes, boundary. grass, range, and wildlife habitat. Capability unit IIw-1; B&A-13 to 15 inches; light grayish brown (10YR Alkali range site. 6/2) silt loam, dark grayish brown (10YR 75-Pedigo silt loam, hardpan substratum. This nearly 4/2) moist; massive; slightly hard, friable, level soil is on bottom lands along drainageways. It has a slightly sticky and slightly plastic; many profile similar to the one described as representative roots; many fine and medium pores; of the series, but there is a cemented hardpan at a neutral ; abrupt wavy boundary. depth of 40 to 60 inches and the soil is very strongly B21t-15 to 19 inches; brown (10YR 5/3) silty alkaline. clay loam, dark brown (10YR 3/3) moist; Included with this soil in mapping are areas of strong fine and medium prismatic poorly drained soils, areas of soils that do not have a structure; very hard, very firm, sticky cemented hardpan, and areas of moderately alkaline and plastic; common roots; many very soils. fine and common fine roots; many fine and Runoff is very slow, and there is little or no hazard of medium pores; many thin clay films and erosion. This soil has very slow permeability. It is black (10YR 2/1) stains on prisms; subject to flooding during winter and spring. A seasonally moderately alkaline; clear wavy boundary. high water table is at a depth of 2 1/2 to 5 feet. B22t-19 to 23 inches; brown (10YR 5/3) silty This soil is used mainly for grass, range, and wildlife clay loam, dark brown (10YR 3/3) moist; habitat. Capability unit VIw-1; Alkali range site. moderate coarse prismatic structure parting to moderate subangular blocky; Reardan Series very hard, very firm, sticky and plastic; few roots; common fine and medium pores; The Reardan series consists of gently sloping to many thin clay films on peds and in pores; strongly sloping, well drained soils that formed in moderately alkaline; clear wavy boundary. layered loess and some volcanic ash. The soils are on B3ca-23 to 28 inches; pale brown (10YR 6/3) silt foot slopes and terraces in the northwestern part of the loam, dark brown (10YR 4/3) moist; strong county. Elevation is about 1,800 to 2,300 feet. The fine and medium prismatic structure native vegetation is mainly Idaho fescue and bluebunch parting to moderate fine and medium wheatgrass. The annual precipitation is 15 to 18 inches. subangular blocky; hard, firm, slightly The frost-free season is 100 to 130 days. sticky and slightly plastic; few roots; In a representative profile the surface layer is dark many fine and medium pores; slightly grayish brown and grayish brown silt loam about 13 effervescent ; moderately alkaline; clear inches thick. Beneath this is a 2-inch-thick layer of light wavy boundary. grayish brown silt loam. The upper part of the subsoil, to Cca-28 to 60 inches ; light yellowish brown (10YR a depth of 23 inches, is brown silty clay loam. The lower 6/4) silt loam, dark yellowish part, to a depth of 28 inches, is pale brown,

structure ; slightly hard, friable, slightly brown (10YR 4/4) moist; massive; slightly sticky and slightly plastic; many roots; 5 hard, friable, slightly sticky and slightly percent lime-silica cemented fragments; plastic; few roots; many fine and medium slightly effervescent; moderately alkaline; pores; most pores coated with lime; slightly abrupt smooth boundary. effervescent ; strongly alkaline. C1ca-8 to 19 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; Depth to bedrock is 40 to more than 60 inches; depth to massive; hard, firm, slightly sticky and lime is 20 to 35 inches. slightly plastic; many roots; few very fine Thickness of the A horizon is 10 to 18 inches. The A and fine pores; lime occurs in pores and in horizon has value of 4 or 5 when dry and 2 or 3 when root channels; 5 percent lime-silica moist, and it has chroma of 2 or 3. The B&A horizon cemented fragments; strongly is 2 to 4 inches thick. The B2t horizon has value of 5 effervescent; moderately alkaline; clear or 6 when dry and 3 or 4 when moist, and it has wavy boundary. chroma of 2 or 3. It is silty clay loam to silty clay. C2casi-19 to 32 inches ; very pale brown (10YR 6/3) Reaction is slightly alkaline to moderately alkaline. The silt loam, brown (10YR 5/3) moist; B3ca and Cca horizons have value of 5 or 6 when dry and 3 massive; very hard, very firm, slightly or 4 when moist. They are silt loam to silty clay loam. sticky and slightly plastic; few roots; few 76-Reardan silt loam, 3 to 15 percent slopes. This very fine and fine pores; lime occurs in pores gently sloping to strongly sloping soil is on foot slopes and in root channels ; 10 percent lime-silica and terraces. cemented fragments ; violently effervescent ; Included with this soil in mapping are areas of soils moderately alkaline; clear wavy boundary. that have a surface layer more than 20 inches thick; C3casi-32 to 43 inches; light gray (10YR 7/2) spots of severely eroded soils, some of which are cal- silt loam, grayish brown (10YR 5/2) careous; areas of soils that have a silty clay loam sur- moist; massive; very hard, very firm, face layer; areas of soils that are silt loam to a depth slightly sticky and slightly plastic; few of 60 inches; and areas of soils that are 20 to 40 inches roots ; few very fine and fine pores; 15 deep to basalt or to loose sand, gravel, and cobbles. percent lime-silica cemented fragments; Runoff is slow to medium, and the erosion hazard is lime occurs in pores and in root channels; slight to moderate. violently effervescent; strongly alkaline; This soil is used mainly for wheat, barley, and peas. clear wavy boundary. Capability unit IIIe-3. C4ca-43 to 60 inches; pale brown (10YR 6/3) silt loam, brown (10YR 5/3) moist; mas- Risbeck Series sive; very hard, firm, slightly sticky and slightly plastic; few roots; few very fine The Risbeck series consists of moderately steep and and fine pores; intermittent weakly to steep, well drained soils that formed in calcareous strongly lime-silica cemented lenses 1/16 to loess and some volcanic ash. The soils are on narrow 1 inch thick; 15 percent lime-silica ridgetops, knobs, and south-facing side slopes on un- cemented fragments ; slightly effervescent; dulating to hilly uplands in the western part of the moderately alkaline. county. Elevation is 1,200 to 2,200 feet. The native vegetation is mainly bluebunch wheatgrass and Idaho Lime-silica cemented fragments make up 5 to 35 fescue. The annual precipitation is 12 to 15 inches. percent of the profile. Lime-silica cemented lenses are The frost-free season is 130 to 155 days. in places, and thickness varies from 1/16 to 1 inch. In a representative profile the surface layer is pale Depth to secondary carbonates is 0 to 10 inches. brown calcareous silt loam about 8 inches thick. The The Ap horizon has value of 6 or 7 when dry and 3 underlying material, to a depth of 60 inches, is pale or 4 when moist, and it has chroma of 2 or 3 when dry brown, very pale brown, and light gray, calcareous silt or moist. The Cca or Ccasi horizons have value of 6 or loam. There are lime-silica cemented fragments 7 when dry and 3 to 5 when moist, and they have throughout the soil. Lime-silica cemented lenses, 1/16 chroma of 1 to 3. Reaction is moderately alkaline to to 1 inch thick, occurs in some places. strongly alkaline. Risbeck soils have moderate or moderately slow , 77-Risbeck silt loam, 15 to 40 percent slopes. This permeability. The available water capacity is high. Roots moderately steep and steep soil is on narrow ridgetops, penetrate to a depth of 60 inches or more. Risbeck knobs, and south-facing side slopes. It has the profile soils are used mainly for wheat, alfalfa, grass, and described as representative of the series. range. Included with this soil in mapping are areas of soils Representative profile of Risbeck silt loam, 15 to 40 that are not calcareous in the surface layer and concave percent slopes, in a cultivated area, 1,800 feet west areas of soils that are not calcareous in the surface and 2,400 feet north of the southeast corner of sec. 18, layer and subsoil. T. 15 N., R. 40 E. Runoff is medium to rapid, and the erosion hazard Ap-0 to 8 inches; pale brown (10YR 6/3) silt is moderate or high. loam, dark grayish brown (10YR 4/2) This soil is used mainly for wheat, alfalfa, grass, moist; weak fine and medium granular and range. Capability unit VIe-2 ; Loamy range site (L-2).

Ritzville Series value of 4 or 5 when dry and 3 or 4 when moist, and it has chroma of 3 or 4. Reaction is neutral or mildly The Ritzville series consists of gently sloping to very alkaline in the A and B horizons. The Cca horizon has steep, well drained soils that formed in loess and some value of 6 or 7 when dry and 4 or 5 when moist, and it has volcanic ash. The soils are on rolling to hilly uplands chroma of 2 or 3. It is moderately alkaline or strongly in the southwestern part of the county. Elevation is 1,000 alkaline. to 2,000 feet. The native vegetation is mainly bluebunch 78-Ritzville silt loam, 3 to 30 percent slopes. This wheatgrass and Idaho fescue. The annual precipitation is gently sloping to moderately steep soil is on uplands. It 11 to 12 inches. The frost-free season is 140 to 155 days. has the profile described as representative of the series. In a representative profile the surface layer is grayish Included with this soil in mapping are areas of soils brown silt loam about 11 inches thick. The subsoil, to a that have a lime-silica cemented hardpan or basalt depth of 38 inches, is brown silt loam. The substratum, bedrock at a depth of 20 to 40 inches ; areas of soils in to a depth of 60 inches, is pale brown and light gray which depth to lime is more than 43 inches; spots of calcareous silt loam. severely- eroded soils, some of which are calcareous ; Ritzville soils have moderate permeability. The available and areas of soils that have a thin surface layer, on water capacity is high. Roots penetrate to a depth of 60 narrow ridges and knobs. inches or more. Ritzville soils are used mainly for Runoff is slow to medium, and the erosion hazard is wheat, grass, alfalfa, range, and wildlife habitat. slight or moderate. Representative profile of Ritzville silt loam, 3 to 30 This soil is used mainly for wheat, grass, alfalfa, percent slopes, in a cultivated area, 700 feet west and 1,140 range, and wildlife habitat. Capability unit IIIe-1; feet south of the north quarter-corner of sec. 25, T. 13 N., Loamy range site (L-2). R. 37 E. 79-Ritzville silt loam, 30 to 40 percent slopes. This Ap1-0 to 6 inches; -ravish brown (10YR 5/2) steep soil is on uplands in the southwestern part of the silt loam, dark brown (10YR 3/2) moist; county. It has a profile similar to the one described as weak fine granular structure; soft, very representative of the series, but the surface layer is 2 friable, slightly sticky and slightly plastic; to 3 inches thinner. many roots; mildly alkaline; abrupt Included with this soil in mapping are areas of soils smooth boundary. that have a lime-silica cemented hardpan or bedrock at a Ap2-6 to 11 inches; grayish brown (10Y R 5/2) depth of 20 to 40 inches; areas of soils that have a silt loam, dark brown (10YR 3/2) moist; high content of volcanic ash; areas of severely eroded, massive; soft, very friable, slightly sticky calcareous soils; areas of soils with a thin surface and slightly plastic; many roots; few fine layer, on ridgetops and knobs; and areas of soils that tubular pores; mildly alkaline; abrupt have slopes of more than 40 percent. smooth boundary. Runoff is rapid, and the erosion hazard is high. B2-11 to 27 inches; brown (10YR 5/3) silt loam, This soil is used mainly for wheat, alfalfa, grass, dark brown (10YR 4/3) moist; weak wildlife habitat, and range. Capability unit IVe-1; coarse prismatic structure; slightly hard, Loamy range site (L-2). friable, slightly sticky and slightly plastic; 80-Ritzville silt loam, 40 to 65 percent slopes. This many roots; many fine tubular pores; mildly steep to very steep soil is on uplands in the alkaline; gradual wavy boundary. southwestern part of the county. It has a profile B3-27 to 38 inches; brown (10YR 5/3) silt loam, similar to the one described as representative of the dark brown (10YR 4/3) moist; weak series, but the surface layer is 2 to 4 inches thinner. coarse prismatic structure; slightly hard, Included with this soil in mapping are areas of soils friable, slightly sticky and slightly plastic; that have a lime-silica cemented hardpan at a depth common roots ; many fine pores; mildly of 20 to 40 inches; areas of soils that have a high alkaline; gradual wavy boundary. content of volcanic ash; areas of soils in which depth C1ca-38 to 43 inches; pale brown (10YR 6/3) to lime is more than 43 inches; spots of severely eroded silt loam, dark grayish brown (10YR 4/2) soils, some of which are calcareous; and areas on narrow moist; massive; slightly hard, friable, ridges and knobs of soils that have a thin surface slightly sticky and slightly plastic; common layer. roots ; many fine pores; slightly effervescent; Runoff is very rapid, and the erosion hazard is very moderately alkaline; abrupt wavy boundary. high. C2ca-43 to 60 inches; light gray (10YR 7/2) The soil is used mainly for range and for wildlife silt loam, grayish brown (10YR 5/2) habitat. Capability unit VIIe-1; North exposure range moist; massive; slightly hard, friable, site (N-1). slightly sticky and slightly plastic; few roots; strongly effervescent; strongly Riverwash alkaline. 81-Riverwash. These miscellaneous areas consist of Depth to secondary carbonates is 30 to 43 inches. deep, somewhat excessively drained and excessively Thickness of the A horizon is 8 to 14 inches. The A drained soils that formed in alluvium. They are along horizon has value of 4 or 5 when dry and 2 or 3 when streams, on islands, and on bars along the moist, and it has chroma of 2 or 3. The B horizon has drainageways of the Palouse and Snake Rivers. The native vegetation is sparse willow, shrubs, grass, and weeds. Roots penetrate to bedrock. Roloff soils are used mainly The mean annual precipitation is 11 to 18 inches. The for wheat, range, and wildlife habitat. frost-free season is 140 to 160 days. Representative profile of Roloff silt loam, 0 to 15 These soils are generally very cobbly coarse sand percent slopes, in an area of grassland, 700 feet east underlain by stratified cobbles, boulders, gravel, and and 600 feet north of the west quarter-corner of sec. sand to a depth of 60 inches or more, but it is variable. 17, T. 14 N., R. 37 E.: Slopes are 0 to 7 percent. Riverwash is subject to A11-0 to 6 inches; grayish brown (10YR 5/2) silt flooding during spring. loam, very dark grayish brown (10YR 3/2) These soils are used for wildlife habitat, for recrea- moist; weak thick platy structure parting tional areas, and for esthetic purposes. Capability unit to weak fine granular structure ; slightly VIII-w-1. hard, friable, slightly sticky and slightly plastic; many roots; neutral; abrupt Rock Outcrop smooth boundary. A12-6 to 11 inches; grayish brown (10YR 5/2) 82-Rock outcrop. These miscellaneous areas are silt loam, very dark grayish brown (10YR nearly level to very steep and are in the channeled 3/2) moist; weak medium prismatic scablands and along the drainageways of Rock Creek structure; slightly hard, friable, slightly and the Palouse and Snake Rivers. They consist mainly sticky and slightly plastic; many roots; of exposed basalt. They are essentially barren or at many very fine to medium tubular pores; most support a sparse stand of vegetation. neutral; clear smooth boundary. Areas more than 5 acres in size are delineated on the B21-11 to 19 inches; brown (10YR 5/3) silt loam, soil map, and smaller areas are shown by an dark brown (10YR 3/3) moist; weak escarpment symbol. medium prismatic structure ; slightly hard, Included with Rock outcrop in mapping in some friable, slightly sticky and slightly plastic; places are areas that have a very thin layer of soil many roots; common very fine to material over bedrock. medium tubular pores; mildly alkaline; This miscellaneous area is used for wildlife habitat, clear smooth boundary. recreational areas, and esthetic purposes. Capability B22-19 to 28 inches; pale brown (10YR 6/3) silt unit VIIIs-1. loam, dark yellowish brown (10YR 3/4) 83-Rock outcrop-Lithic Xerorthents complex, 0 to 30 moist; weak medium prismatic structure; percent slopes. These nearly level to moderately steep slightly hard, friable, slightly sticky and soils are in channeled scablands and along the slightly plastic; common roots; many drainageways of the Palouse and Snake Rivers and fine to medium tubular pores; 5 percent Rock Creek. Areas vary in size. This complex consists coarse fragments; mildly alkaline; clear of 65 percent Rock outcrop and as much as 30 percent smooth boundary. Lithic Xerorthents. IIR-28 inches; basalt, slightly fractured. Included with this complex in mapping are small areas of gravelly and stony soils that are more than 12 Depth to bedrock is 20 to 40 inches. inches deep. Included areas make up about 5 percent of Thickness of the A horizon is 10 to 16 inches. The the mapped acreage. A horizon has value of 4 or 5 when dry and 2 or 3 Runoff is slow to medium, and the erosion hazard is when moist, and it has chroma of 2 or 3 when moist slight or moderate. or dry. It is silt loam or cobbly silt loam. The B2 This complex is used mainly for wildlife habitat and for horizon has value of 5 or 6 when dry and 3 or 4 when grazing to a limited extent in spring. Capability unit moist. The lower part of the B horizon is 2 to 25 VIIIs-1. percent gravel-sized fragments. 84-Roloff silt loam, 0 to 15 percent slopes. This Roloff Series nearly level to strongly sloping soil is on outwash terraces. It has the profile described as representative The Roloff series consists of nearly level to strongly of the series. sloping, well drained soils underlain by basalt bedrock Included with this Soil in mapping are areas of at a depth of 20 to 40 inches. The soils formed in Rock outcrop, soils that are less than 20 inches or more glacial outwash derived from basalt, loess, and some than 40 inches deep to bedrock, and soils that have volcanic ash. They are on outwash terraces and uplands gravel and cobbles at a depth of 20 to 40 inches. that border steep canyons along drainageways in the Runoff is very slow to medium, and the hazard of western part of the county. Elevation is 800 to 1,700 erosion is slight or moderate. feet. The native vegetation is mainly bluebunch This soil is used mainly for wheat, range, and wild wheatgrass and Idaho fescue. The annual precipitation life habitat. Capability unit IVe-7; Loamy range site is 11 to 12 inches. The frost-free season is 135 to 155 (L-2). days. 85-Roloff cobbly silt loam, 0 to 15 percent slopes. In a representative profile the surface layer is grayish This nearly level to strongly sloping soil is on outwash brown silt loam about 11 inches thick. The subsoil, to a terraces. It has a profile similar to the one described as depth of 28 inches, is brown and pale brown silt loam representative of the series, but the surface layer is underlain by basalt bedrock. cobbly and the subsoil has more gravel and cobbles. Roloff soils have moderate permeability. The available Included with this soil in mapping are areas of soils water capacity is moderate or moderately high. that are not cobbly, soils that have gravel and cobbles at a depth of 20 to 40 inches, stony and very stony ture ; slightly hard, friable, slightly sticky soils, soils that are less than 20 inches deep to bedrock, and slightly plastic; many fine roots; and Rock outcrop. neutral; abrupt smooth boundary. Runoff is very slow to medium, and the erosion A12-6 to 12 inches; dark grayish brown (10YR hazard is slight or moderate. 4/2) silt loam, very dark brown (10YR This soil is used mainly for range and for wildlife 2/2) moist; moderate medium subangular habitat. Capability unit VIe-1; Loamy range site (L-2). blocky structure; slightly hard, friable, 86-Roloff-Starbuck complex, 0 to 30 percent slopes. slightly sticky and slightly plastic; many These nearly level to moderately steep soils are on roots; many fine pores; neutral_ ; gradual outwash terraces and upper edges of steep canyon sides wavy boundary. along drainageways. This complex consists of 40 A3-12 to 19 inches; grayish brown (10YR 5/2) silt percent Roloff silt loam that has slopes of 0 to 30 loam, very dark grayish brown (10YR 3/2) percent, on mounds and fingers, and 30 percent Star- moist; moderate coarse subangular blocky buck cobbly silt loam that has slopes of 0 to 30 percent. structure; slightly hard, friable, slightly The mounds range from 10 to 30 feet in diameter, are sticky and slightly plastic; common roots; generally 5 to 20 feet apart and are generally 1 to 4 many fine pores; 5 percent gravel; feet high. neutral; abrupt wavy boundary. Included with these soils in mapping are areas of B21t-19 to 31 inches; dark brown (7.5YR 4/4) soils that are deeper than 40 inches to bedrock, areas of silty clay loam, dark brown (7.5YR 3/4) soils that are less than 10 inches deep to bedrock, areas moist; strong fine and medium angular of Rock outcrop, soils in small basins, areas of soils blocky structure; very hard, very firm, that have gravel and cobbles at a depth of 20 to 40 sticky and plastic; few roots; few inches, areas of stony and very stony soils, and areas medium pores; thick continuous clay films of soils that have a cobbly surface layer. Included areas on peds ; 15 percent gravel ; neutral ; clear make up about 30 percent of the mapped acreage. wavy boundary. Runoff is very slow to medium, and the erosion B22t-31 to 37 inches; brown (7.5YR 5/4) silty hazard is slight or moderate. clay loam, dark brown (7.5YR 4/4) moist; These soils are used mainly for range and for wildlife strong fine and medium blocky structure; habitat. Capability unit VIe-1; Roloff part in Loamy very hard, very firm, sticky and plastic; range site (L-2), Starbuck part in Shallow range site (S- few fine roots; few medium pores; thick 2). continuous clay films on peds ; 10 percent gravel; neutral; clear wavy boundary. Schumacher Series B3-37 to 43 inches; brown (7.5YR 5/4) silty clay loam, dark brown (7.5YR 4/4) moist; The Schumacher series consists of gently sloping to moderate fine subangular blocky structure; steep, well drained soils underlain by metasedimentary very hard, very firm, sticky and plastic; rock at a depth of 40 to 60 inches. The soils formed in very few fine roots; many very fine pores; loess and some volcanic ash and weathered residuum thin continuous clay films on peds ; 12 from metasediment. They are on foot slopes of buttes in percent gravel; neutral. the eastern part of the county. Elevation is 2,200 to R-43 inches; metasedimentary rock. 3,600 feet. The native vegetation is mainly Idaho fescue, rough fescue, and bluebunch wheatgrass. The Depth to bedrock is 40 to 60 inches. annual precipitation is 18 to 23 inches. The frost-free The A horizon has value of 4 or 5 when dry and 2 season is 100 to 130 days. or 3 when moist, and it has chroma of 1 or 2 when In a representative profile the surface layer is dark dry or moist. This horizon is 0 to 5 percent gravel. grayish brown and grayish brown silt loam about 19 The B2t horizon has value of 4 to 6 when dry and 3 inches thick. The subsoil, to a depth of 43 inches, is or 4 when moist, chroma of 3 or 4 when dry or moist, brown and dark brown silty clay loam underlain by and hue of 7.5YR or 10YR. It is silty clay loam or heavy metasediments. There are pebbles throughout the profile; silt loam and is 2 to 15 percent gravel and has a few the amount increases with depth. manganese shot in some pedons. The B3 horizon has Schumacher soils have moderately slow permeability. value of 5 to 7 when dry and 3 to 5 when moist, and it The available water capacity is high. Roots penetrate to has chroma of 3 or 4. It is heavy silt loam or silty clay the metasediment. Schumacher soils are used mainly for loam and is 12 to 30 percent gravel. It has gray silt and wheat, barley, peas, lentils, alfalfa, grass, range, and sand particles in some places on peds. wildlife habitat. 87-Schumacher silt loam, 3 to 15 percent slopes. Representative profile of Schumacher silt loam, 3 to This gently sloping to strongly sloping soil is on foot 15 percent slopes, in a cultivated area, 1,500 feet south slopes of buttes. It has the profile described as and 1.800 feet east of the northwest corner of sec. 19, T. representative of the series. 19 N., R. 44 E. Included with this soil in mapping are areas of Rock Ap-0 to 6 inches; dark grayish brown (10YR outcrop, soils that are 20 to 40 inches deep to bedrock, 4/2) silt loam, very dark brown (10YR soils that are deeper than 60 inches to bedrock, and 2/2) moist; weak fine granular struc- soils in swales where the surface layer is thicker than 20 inches.

Runoff is slow to medium, and the hazard of erosion is sticky and slightly plastic; many fine slight to moderate. roots; common very fine and fine pores; This soil is used mainly for wheat, barley, peas, neutral ; abrupt smooth boundary. lentils, alfalfa, and grass. Capability unit IIIe-8. A11-4 to 22 inches; dark grayish brown (10YR 88-Schumacher silt loam, 15 to 25 percent slopes. This 4/2) silt loam, very dark brown (10YR moderately steep soil is on foot slopes of buttes. It has a 2/2) moist; weak fine and medium prismatic profile similar to the one described as representative structure; slightly hard, friable, slightly of the series, but the surface layer is 2 to 3 inches sticky and slightly plastic; many fine roots; thinner. common very fine and fine pores; neutral; Included with this soil in mapping are areas of Rock clear wavy boundary. outcrop, areas of soils that have a silty clay subsoil, A12-22 to 33 inches; dark grayish brown (10YR spots of severely eroded soils on ridges and knobs, 4/2) silt loam, very dark brown (10YR areas of soils that have bedrock at a depth of 20 to 40 2/2) moist; massive; slightly hard, inches, and areas on north-facing side slopes and in friable, slightly sticky and slightly plastic; swales of soils that have a surface layer more than 20 common fine roots; common very fine and inches deep and a subsoil of silt loam to a depth of 60 fine pores; neutral; clear wavy boundary. inches. AC-33 to 60 inches; grayish brown (10YR 5/2) Runoff is medium, and the erosion hazard is moderate. silt loam, very dark grayish brown (10YR This soil is used mainly for wheat, barley, peas, 3/2) moist; massive ; slightly hard, friable, lentils, alfalfa, grass, range, and wildlife habitat. slightly sticky and slightly plastic; few Capability unit IVe-8; Loamy range site (L-3). fine roots; common fine pores; mildly 89-Schumacher silt loam, 25 to 40 percent slopes. This alkaline. moderately steep to steep soil is on foot slopes of buttes. It has a profile similar to the one described as Thickness of the Ap and A1 horizons is 30 to 48 representative of the series, but the surface layer is 3 inches. The control section, between depths of 10 and to 5 inches thinner. 40 inches, is 18 to 22 percent clay. Included with this soil in mapping are small areas of The A horizon has value of 2 or 3 when moist and Rock outcrop; areas of soils that are 20 to 40 inches deep 4 or 5 when dry, and it has chroma of 1 or 2 when dry to bedrock, areas of silt loams that are 60 inches deep, or moist. It is neutral to mildly alkaline. The AC areas on north-facing slopes and in swales of soils horizon has value of 3 or 4 when moist and 5 or. 6 that have a surface layer more than 2 feet thick, and when dry, and it has chroma of 2 or 3 when dry or spots of severely eroded soils on ridges and knobs. moist. It is neutral to moderately alkaline. Runoff is rapid, and the erosion hazard is high. 90-Snow silt loam, 7 to 15 percent slopes. This This soil is used mainly for range and for wildlife strongly sloping soil is on foot slopes and terraces. habitat. Capability unit VIe-1; Loamy range site (L-3). Included with this soil in mapping are spots of severely eroded soils and areas of soils that have a Snow Series silty clay or silty clay loam subsoil. Runoff is medium, and the erosion hazard is moderate. The Snow series consists of strongly sloping, well This soil is used mainly for wheat, barley, peas, drained soils that formed in colluvium and alluvium lentils, grass, and alfalfa. Capability unit IIIe-4. from loess and some volcanic ash. The soils are on foot slopes and terraces in the eastern part of the Speigle Series county. Elevation is 1,800 to 2,300 feet. The native vegetation is mainly Idaho fescue, bluebunch The Speigle series consists of well drained, gently wheatgrass, and snowberry. The annual precipitation is sloping to very steep, very stony soils underlain by 18 to 23 inches. The frost-free season is 115 to 125 days. basalt at a depth of 40 to more than 60 inches. The In a representative profile the surface layer is dark soils formed in loess, volcanic ash, and weathered grayish brown silt loam about 33 inches thick. The basalt residuum. They are on canyon walls along next layer, to a depth of 60 inches, is grayish brown silt drainageways of the Palouse River and in the Rock loam. Lake area. Elevation is 1,600 to 3,000 feet. The native Snow soils have moderate permeability. The available vegetation is mainly ponderosa pine, pine grass, ninebark, water capacity is high. Roots penetrate to a depth of 60 and snowberry and some Douglas-fir. The annual inches or more. Snow soils are used mainly for wheat, precipitation is 16 to 23 inches. The frost-free season is barley, peas, lentils, grass, and alfalfa. 110 to 135 days. Representative profile of Snow silt loam, 7 to 15 In a representative profile the surface layer is dark percent slopes, in a cultivated area, 1,400 feet north grayish brown and grayish brown, very stony silt loam and 400 feet west of the southeast corner of sec. 20, T. and cobbly silt loam about 32 inches thick. The subsoil, to 16 N., R. 43 E. a depth of 44 inches, is brown cobbly silt loam. The Ap-0 to 4 inches; grayish brown (10YR 4/2) silt substratum, to a depth of 60 inches, is brown and very loam, very dark brown (10YR 2/2) moist; pale brown, very cobbly silt loam. weak fine and medium granular structure; Speigle soils have moderate permeability. The slightly hard, friable, slightly available water capacity is moderately high. Roots penetrate to a depth of 40 to more than 60 inches.

at a depth of 44 inches ; neutral; clear Speigle soils are used mainly for woodland, woodland wavy boundary. grazing, and wildlife habitat. C2-51 to 54 inches; very pale brown (10YR 7/4) Representative profile of Speigle very stony loam, in an very cobbly silt loam, yellowish brown area of Speigle-Rock outcrop complex, 30 to 65 percent (10YR 5/4) moist; massive; slightly hard, slopes, in an area of woodland, 2,400 feet west and 2,300 friable, slightly sticky and slightly plastic; feet north of the southeast corner of sec. 12, T. 17 N., R. few roots; many very fine and fine 44 E. pores; 60 percent angular basalt O1-2 to 1 1/2 inches; recent deposition of pine fragments larger than 2 millimeters; needles, twigs, and organic debris. fines on basalt gravel and cobbles ; O2-1 1/2 inches to 0; decomposed organic neutral; clear wavy boundary. matter. C3-54 to 60 inches ; brown (10YR 5/3) very cobbly A11-6 to 3 inches; dark grayish brown (10YR 4/2) silt loam, dark brown (10YR 3/3) moist; very stony silt loam, very dark brown massive; slightly hard, friable, slightly (10YR 2/2) moist; weak fine and medium sticky and slightly plastic; few roots; granular structure; slightly hard, friable, many very fine and fine pores; 60 percent slightly sticky and slightly plastic ; many angular basalt fragments larger than 2 roots ; many very fine and fine pores; 25 millimeters; fines on basalt gravel and percent angular basalt fragments larger cobbles; neutral. than 2 millimeters; neutral; abrupt smooth boundary. Depth to bedrock is 40 to 60 inches or more. A12-3 to 13 inches; dark grayish brown (10YR Thickness of the A horizon is 20 to 35 inches. The 4/2) cobbly silt loam, very dark grayish A horizon has value of 4 or 5 when dry and 2 or 3 when brown (10YR 3/2) moist; weak fine and moist, and it has chroma of 2 when dry or moist. The medium granular structure; slightly hard, B and C horizons have value of 5 to 7 when dry and 3 friable. slightly sticky and slightly plastic; to 5 when moist, and they have chroma of 3 or 4 when many roots ; many very fine and fine pores; dry or moist. The B and C horizons are 40 to 75 percent 35 percent angular basalt fragments gravel, cobbles, and stones. Reaction is neutral to mildly larger than 2 millimeters; neutral; clear alkaline. wavy boundary. The Speigle soils in this survey area have a thicker A13-13 to 20 inches; grayish brown (10YR 5/2) A horizon than that defined in the range for the series cobbly silt loam, very dark grayish brown and some areas are shallower, 40 to 60 inches to (10YR 3/2) moist; weak fine and medium basalt, but these differences do not alter their useful subangular blocky structure; slightly hard, ness or behavior. The dark color of the A horizon is friable, slightly sticky and slightly mostly a result of the dark colored basalt sand in the plastic; many roots; many very fine and soil. fine pores; 40 percent angular basalt 91-Speigle-Rock outcrop complex, 3 to 30 percent fragments larger than 2 millimeters ; slopes. These gently sloping to moderately steep soils are neutral; clear wavy boundary. on north- and south-facing side slopes. This complex A3-20 to 32 inches ; grayish brown (10YR 5/2) consists of 70 percent Speigle very stony silt loam and cobbly silt loam, very dark grayish brown 20 percent Rock outcrop. The Speigle soil has a profile (10YR 3/2) moist; weak fine and me- similar to the one described as representative of the dium subangular blocky structure; slightly Speigle series, but the surface layer is 2 to 3 inches hard, friable, slightly sticky and slightly thicker. Rock outcrop is essentially barren. plastic ; common roots; many very fine and Included with these soils in mapping are areas of fine pores; 40 percent angular basalt soils that are nonstony and 60 inches deep and soils fragments larger than 2 millimeters; that have lenses and pockets of volcanic ash in the neutral; clear wavy boundary. subsoil. Included areas make up about 10 percent of B2-32 to 44 inches; brown (10YR 5/3) cobbly the mapped acreage. silt loam, dark brown (10YR 3/3) moist; Runoff is slow to medium, and the erosion hazard is weak fine and medium subangular blocky slight to moderate. structure; slightly hard, friable, slightly These soils are used mainly for woodland, woodland sticky and slightly plastic; common roots; grazing, and wildlife habitat. Capability unit VIs-1. many very fine and fine pores; 40 percent 92-Speigle-Rock outcrop complex, 30 to 65 percent angular basalt fragments larger than 2 slopes. These steep to very steep soils are on north- millimeters ; ash layer 1 inch thick at a facing sides of canyons. This complex consists of 70 depth of 32 to 33 inches; neutral; clear percent Speigle very stony silt loam and 20 percent wavy boundary. Rock outcrop. The Speigle soil has the profile described as C1-44 to 51 inches; brown (10YR 5/3) very representative of the Speigle series. Rock outcrop is cobbly silt loam, dark brown (10YR 3/3) essentially barren. moist; massive; slightly hard, friable, Included with these soils in mapping are areas of slightly sticky and slightly plastic; common stony or cobbly soils that are less than 20 inches deep roots; many very fine and fine pores; 60 and areas of silt loams that are more than 60 inches percent angular basalt fragments larger deep. Included areas make up about 10 percent of the than 2 millimeters ; charcoal layer mapped acreage.

fine and fine pores; thin continuous clay Runoff is rapid to very rapid, and the erosion hazard is films on peds ; few very dark brown (10YR high or very high. 2/2) organic stains on peds ; strongly These soils are used mainly for woodland, woodland alkaline; clear wavy boundary. grazing, and wildlife habitat. Capability unit VIIs-1. B22t-14 to 16 inches; brown (10YR 6/3) silty clay loam, dark brown (10YR 3/3) moist; Spofford Series strong fine and medium prismatic structure parting to strong fine The Spofford series consists of nearly level to strongly subangular blocky; very hard, very firm, sloping, moderately well drained soils that formed in sticky and plastic; few roots; few very fine loess and some volcanic ash underlain by basalt at a and fine pores; thin continuous clay films on depth of 40 to 60 inches or more. The soils are on peds; many very dark brown (10YR 2/2) uplands that border canyon sides along drainageways in organic stains on peds; slightly the central part of the county. Elevation is 1,800 to effervescent ; strongly alkaline; clear wavy 2,600 feet. The native vegetation is mainly bluebunch boundary. wheatgrass and Idaho fescue. The annual precipitation is B3ca-16 to 23 inches; pale brown (10YR 6/3) silt 14 to 18 inches. The frost-free season is 130 to 145 days. loam, dark brown (10YR 4/3) moist; In a representative profile the surface layer is dark moderate fine and medium prismatic grayish brown and grayish brown silt loam about 8 structure; slightly hard, friable, slightly inches thick. The subsurface layer, to a depth of 12 sticky and slightly plastic; few roots; many inches, is light brownish gray silt loam. The upper part very fine and fine pores; lime in pores of the subsoil, to a depth of 16 inches, is brown, cal- and root channels; slightly effervescent; careous silty clay loam. The lower part, to a depth of 23 strongly alkaline; clear wavy boundary. inches, is pale brown, calcareous silt loam. The C1ca-23 to 28 inches; pale brown (10YR 6/3) substratum, to a depth of 60 inches, is pale brown and silt loam, dark brown (10YR 4/3) moist; light gray, calcareous silt loam. weak coarse prismatic structure; slightly Spofford soils have slow permeability. The available hard, friable, slightly sticky and slightly water capacity is moderate to moderately high. Roots plastic; few roots ; many very fine and fine penetrate to a depth of 60 inches, but there are only pores; lime in pores and root channels ; few below a depth of 12 inches. Spofford soils are used strongly effervescent; strongly alkaline; mainly for wheat, barley, alfalfa, grass, range, and clear wavy boundary. wildlife habitat. C2ca-28 to 60 inches; light gray (10YR 7/2) Representative profile of Spofford silt loam, 0 to 15 silt loam, grayish brown (10YR 5/2) percent slopes, in grass, 900 feet north and 20 feet moist; massive; slightly hard, friable, west of the southeast corner of sec. 5, T. 17 N., R. 41 slightly sticky and slightly plastic; few E.: roots ; many fine and very fine pores; lime A11-0 to 2 inches; dark grayish brown (10YR in pores and root channels ; violently 4/2) silt loam, very dark brown (10YR effervescent ; strongly alkaline. 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and Bedrock is at a depth of 40 to 60 inches or more. slightly plastic; many roots; neutral; The A1 horizon has value of 4 or 5 when dry and 2 abrupt smooth boundary. or 3 when moist, and it has chroma of 1 or 2 when dry A12-2 to 8 inches; grayish brown (10YR 5/2) or moist. The A2 horizon is 2 to 6 inches thick. It has a silt loam, very dark grayish brown (10YR value of 5 or 6 when dry and 3 or 4 when moist, and it 3/2) moist; moderately thin and medium has chroma of 2 or 3 when dry or moist. The B2t platy structure; slightly hard, friable, horizon is heavy silt loam to silty clay loam. It has value slightly sticky and slightly plastic; many of 5 or 6 when dry and 3 or 4 when moist, and it has roots; many very fine and fine pores; chroma of 2 or 3 when dry or moist. It is moderately mildly alkaline; clear wavy boundary. alkaline to strongly alkaline. The B3ca horizon has A2-8- to 12 inches; light brownish gray (10YR value of 5 or 6 when dry and 4 or 5 when moist, and it 6/2) silt loam, dark grayish brown (10YR has chroma of 3 or 4 when dry or moist. It is moder 4/2) moist; moderately thin and medium ately alkaline to strongly alkaline. The Cca horizon has platy structure; slightly hard, friable, value of 6 or 7 when dry and 4 or 5 when moist, and it slightly sticky and slightly plastic; many has chroma of 2 or 3 when dry or moist. It is moderately roots ; common very fine and fine pores; alkaline or strongly alkaline. moderately alkaline; abrupt wavy 93-Spofford silt loam, 0 to 15 percent slopes. This boundary. nearly level to strongly sloping soil is on uplands that B21t-12 to 14 inches; brown (10YR 5/3) silty border canyon sides along drainageways. clay loam, dark brown (10YR 3/3) moist; Included with this soil in mapping are areas of soils strong coarse and medium columnar that are 20 to 40 inches deep to basalt bedrock and silt structure parting to strong fine and loams that are 60 inches deep. medium prismatic; very hard, very firm, Runoff is very slow to medium, and the erosion sticky and plastic; few roots; few very hazard is slight or moderate. This soil is used mainly for wheat, barley, alfalfa, grass, range, and wildlife habitat. Capability unit IVe- C1ca-40 to 54 inches; brown (10YR 5/3) silt 11; Loamy range site (L-3). loam, dark brown (10YR 3/3) moist; massive; hard, friable, slightly sticky and Staley Series slightly plastic; few roots; lime in pores and root channels; slightly effervescent; The Staley series consists of strongly sloping to moderately alkaline; clear wavy boundary. moderately steep, well drained soils that formed in C2ca-54 to 60 inches; brown (10YR 5/3) silt loess and volcanic ash. The soils are on ridgetops, loam, dark brown (10YR 3/3) moist; knobs, and south-facing side slopes on uplands in the massive; hard, friable, slightly sticky northeastern part of the county. Elevation is 2,000 to and slightly plastic; few roots; lime in 3,000 feet. The native vegetation is mainly Idaho fescue pores and root channels; slightly effervescent and bluebunch wheatgrass. The annual precipitation is 18 ; strongly alkaline. to 23 inches. The frost-free season is 110 to 130 days. In a representative profile the surface layer is The control section, between depths of 10 and 40 grayish brown silt loam about 18 inches thick. The inches, is 18 to 23 percent clay. Depth to secondary subsoil and substratum, to a depth of 60 inches, are carbonates is 15 to 24 inches. brown calcareous silt loam. The A horizon has value of 4 or 5 when dry and 2 or 3 Staley soils have moderate permeability. The available when moist, and it has chroma of 2 or 3 when dry or water capacity is high. Roots penetrate to a depth of 60 moist. The B horizon is moderately alkaline or strongly inches or more. Staley soils are used mainly for wheat, alkaline. barley, peas, lentils, grass, and alfalfa. 94-Staley silt loam, 7 to 25 percent slopes. This Representative profile of Staley silt loam, 7 to 25 strongly sloping to moderately sloping soil is on ridgetops, percent slopes, in a cultivated area, 1,140 feet south knobs, and south-facing side slopes on uplands. and 360 feet west of the northeast corner of sec. 27, T. Included with this soil in mapping are spots of 18 N., R. 43 E. severely eroded, calcareous soils, areas of soils in which the Ap-0 to 7 inches; grayish brown (10YR 5/2) silt depth to lime is more than 40 inches, areas on top of loam, very dark grayish brown (10YR 3/2) ridges and knobs of soils that have a thin surface layer, moist; weak fine and medium granular areas in swales of soils that have a surface layer 2 feet structure; slightly hard, friable; slightly or more thick, and areas of soils that have a silty clay sticky and slightly plastic; many roots; loam subsoil. neutral; abrupt smooth boundary. Runoff is medium, and the erosion hazard is moderate. A3-7 to 18 inches; grayish brown (10YR 5/2) silt This soil is used mainly for wheat, barley, peas, loam, very dark grayish brown (10YR 3/2) lentils, grass, and alfalfa. Capability unit IVe-10. moist; weak fine and medium subangular blocky structure; slightly hard, friable, Starbuck Series slightly sticky and slightly plastic; many roots; mildly alkaline; clear wavy The Starbuck series consists of well drained, cobbly boundary. soils underlain by basalt at a depth of 10 to 20 inches. B21ca-18 to 21 inches; brown (10YR 5/3) silt The soils formed in loess and some volcanic ash and loam, dark brown (10YR 3/3) moist; weathered residuum from basalt. They are steep and weak fine and medium prismatic very steep in canyons along major drainageways and are structure parting to weak fine and nearly level to moderately steep in channeled scablands in medium subangular blocky; hard, friable, the southwestern part of the county. Elevation is 600 to slightly sticky and slightly plastic; 3,000 feet. The native vegetation is mainly bluebunch common roots; common fine pores; lime in wheatgrass and Sandberg wheatgrass. The annual pores and root channels and on peds ; precipitation is 11 to 12 inches. The frost-free season is slightly effervescent; moderately alkaline; 150 to 160 days. clear wavy boundary. In a representative profile the surface layer is about 9 B22ca-21 to 29 inches; brown (10YR 5/3) silt inches thick. It is grayish brown cobbly silt loam in the loam, dark brown (10YR 3/3) moist; upper 3 inches and brown gravelly silt loam in the lower 6 moderate medium prismatic structure; inches. The subsoil is pale brown gravelly loam which hard, friable, slightly sticky and slightly extends to bedrock at a depth of 15 inches. plastic; common roots; common fine Starbuck soils have moderate permeability. The pores ; lime in pores and root channels available water capacity is low. Roots penetrate to and on peds; slightly effervescent; bedrock, and some extend into fractures. Starbuck soils moderately alkaline; clear wavy boundary. are used mainly for range and for wildlife habitat. B3ca-29 to 40 inches; brown (10YR 5/2) silt loam, Representative profile of Starbuck cobbly silt loam, in an dark brown (10YR 3/3) moist; weak fine and area of Starbuck-Alpowa complex, 30 to 65 percent medium prismatic structure; hard, friable, slopes, in an area of grassland. 1,900 feet east and 1,300 slightly sticky and slightly plastic; feet south of the northwest corner of sec. 22, T. 13 N., R. common roots ; lime in pores and root 39 E. channels and on peds; slightly A11-0 to 3 inches; grayish brown (10YR 5/2) effervescent; moderately alkaline; clear cobbly silt loam, very dark grayish brown wavy boundary. (10YR 3/2) moist; weak fine granular

structure ; slightly hard, friable, slightly loess and volcanic ash. They are on outwash terraces of sticky and slightly plastic; many fine channeled scablands in the southwestern part of the roots; many fine and very fine tubular county. Elevation is 600 to 1,700 feet. The native pores; 25 percent angular basalt vegetation is mainly bluebunch wheatgrass and Sandberg fragments larger than 2 millimeters; wheatgrass. The annual precipitation is 11 to 12 inches. mildly alkaline ; clear wavy boundary. The frost-free season is 140 to 160 days. A12-3 to 9 inches; brown (10YR 5/3) gravelly In a representative profile the surface layer is grayish silt loam, dark brown (10YR 3/3) moist; brown loam about 8 inches thick. The subsoil, to a depth weak fine and medium subangular blocky of 16 inches, is brown loam. The substratum, to a depth structure; slightly hard, friable; slightly of 24 inches, is pale brown gravelly loam. Below this, sticky and slightly plastic; many fine to a depth of 60 inches, it is loose very gravelly coarse roots; many very fine tubular pores; 35 sand. The undersides of pebbles are coated with lime percent angular basalt fragments larger and silica. There is basaltic gravel throughout the than 2 millimeters; mildly alkaline; profile, and the amount increases with depth. abrupt irregular boundary. Stratford soils have moderate permeability. The B2-9 to 15 inches; pale brown (10YR 6/3) available water capacity is moderate or moderately gravelly loam, dark brown (10YR 4/3) high. Root penetration is somewhat limited by the moist; weak medium subangular blocky very gravelly coarse sand at a depth of 20 to 40 inches. structure; slightly hard, friable, slightly Stratford soils are used mainly for wheat, range, and sticky and slightly plastic; many fine roots; wildlife habitat. many fine tubular pores; 30 percent Representative profile of Stratford loam, 0 to 15 per angular basalt fragments larger than 2 cent slopes, in an area of grassland, 900 feet West and millimeters; neutral; abrupt wavy 340 feet south of the east quarter-corner of sec. 36, T. boundary. 13 N., R. 37 E.: R-15 inches; basalt. A1-0 to 8 inches; grayish brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) Basalt is at depth of 10 to 20 inches. The control moist; weak thin platy structure; soft, section, between a depth of 10 inches and bedrock, is 5 very friable, slightly sticky and slightly to 35 percent gravel, cobbles, and stones. plastic; many fine roots; mildly alkaline; The A horizon has value of 5 or 6 when dry and 3 clear smooth boundary. or 4 when moist, and it has chroma of 2 or 3 when dry B2-8 to 16 inches; brown (10YR 5/3) loam, dark or moist. It is loam or silt loam and is cobbly and brown (10YR 3/3) moist; massive; slightly gravelly. The B horizon has value of 5 or 6 when dry hard, friable, slightly sticky and slightly and 3 or 4 when moist, and it has chroma of 3 or 4 plastic; many fine roots ; common fine when dry or moist. It is gravelly loam or gravelly silt pores; 10 percent fine gravel; mildly loam. alkaline; clear wavy boundary. 95-Starbuck-Alpowa complex, 30 to 65 percent slopes. C1-16 to 24 inches; pale brown (10YR 6/3) These steep and very steep soils are in canyons. This gravelly loam, dark brown (10YR 4/3) complex consists of 50 percent Starbuck cobbly silt moist; massive; slightly hard, friable, loam and 25 percent Alpowa cobbly silt loam. The nonsticky and nonplastic; many fine roots; Starbuck soil has the profile described as representative of 50 percent gravel ; mildly alkaline; abrupt the Starbuck series. The Alpowa soil has a profile smooth boundary. similar to the one described as representative of the IIC2ca-24 to 60 inches; very gravelly coarse sand; Alpowa series, but it is more than 60 inches deep to pebbles have common lime-silica coatings on basalt. underside; slightly effervescent ; moderately Included with these soils in mapping are areas of alkaline. soils that have a very fine sandy loam surface layer, soils that are less than 10 inches deep to bedrock, Depth to the very gravelly coarse sand is 20 to 40 Rock outcrop, soils that have a sandy loam surface inches. layer and are 20 to 40 inches deep to loose coarse sand, Thickness of the A horizon is 6 to 12 inches. The A and soils that have bedrock at a depth of 20 to 40 horizon has value of 4 or 5 when dry and 2 or 3 when inches. Included areas make up about 25 percent of moist, and it has chroma of 2 or 3. It is loam or very the mapped acreage. cobbly loam. The B horizon has value of 5 or 6 when dry and Runoff is rapid to very rapid, and the erosion hazard is 3 or 4 when moist, and it has chroma of 3 or 4. It is high or very high. gravelly loam or gravelly silt loam. The C1 horizon has These soils are used mainly for range and for wildlife value of 5 or 6 when dry and 3 or 4 when moist, and it habitat. Capability unit VIIe-1; Starbuck part in has chroma of 3 or 4. It is gravelly loam or gravelly Shallow range site (S-2), Alpowa part in North silt loam. In places it is calcareous in the lower part. exposure range site (N-1). The IIC2ca horizon is mildly alkaline or moderately alkaline. Stratford Series 96-Stratford loam, 0 to 15 percent slopes. This nearly level to strongly sloping soil is on outwash The Stratford series consists of nearly level to terraces. It has the profile described as representative of strongly sloping, well drained soils underlain by very the series. gravelly coarse sand at a depth of 20 to 40 inches. The Included with this soil in mapping are areas of Rock soils formed in gravelly alluvium derived partly from

outcrop, soils that have basalt bedrock or basaltic sand at a depth of 20 to 40 inches, soils that have a sandy loam surface layer, and soils that have basalt at a depth of more than 40 inches. Runoff is very slow to medium, and the erosion hazard is slight or moderate. This soil is used mainly for wheat, range, and wildlife habitat. Capability unit IVe-7 ; Loamy range site (L-2). 97-Stratford very cobbly loam, 0 to 15 percent slopes. This nearly level to strongly sloping soil is on outwash plains and terraces. It has a profile similar to the one described as representative of the series, but the surface layer is 2 to 3 inches thinner and it is very cobbly. Included with this soil in mapping are areas of Rock outcrop, escarpments where slopes are more than 15 percent, soils that have basalt or basaltic sand at a depth of less than 10 inches, soils that have basalt bedrock at a depth of 20 to 40 inches, stony and very stony soils, and soils that are free of cobbles. Runoff is very slow to medium, and the erosion hazard is slight to moderate. This soil is used mainly for range and for wildlife habitat. Capability unit VIIs- 1; Loamy range site (L-2).

Tekoa Series

The Tekoa series consists of gently sloping to very steep, well drained soils underlain by unconsolidated metasediment at a depth of 20 to 40 inches. The soils formed in loess, volcanic ash, and weathered metasedi- ments. They are on buttes in the eastern part of the county. Elevation is 2,000 to 4,000 feet. The native vegetation is mainly bluebunch wheatgrass, Idaho fescue, rough fescue, and scattered ponderosa pine. The annual precipitation is 20 to 23 inches. The frost-free season is 100 to 130 days. In a representative profile the surface layer is dark grayish brown and grayish brown gravelly silt loam about 7 inches thick. The subsoil, to a depth of 20 inches, is brown and pale brown gravelly loam. The substratum, to a depth of 40 inches, is yellow very gravelly loam. Below this, it is unconsolidated metased- iment (fig. 17). Tekoa soils have moderate permeability. The available water capacity is moderate or moderately high. Roots penetrate to the metasediment. Tekoa soils are used mainly for wheat, barley, peas, lentils, grass, range, Figure 17.-Profile of Tekoa gravelly silt loam, 25 to 55 percent woodland, and wildlife habitat. slopes, overlying unconsolidated metasediments. Representative profile of Tekoa gravelly silt loam, 25 to 55 percent slopes, in an area of grassland, 1,700 feet west and 200 feet south of the northwest corner of sec. 2, brown (10YR 3/2) moist; weak fine and T. 20 N., R. 45 E.: medium subangular blocky structure; A11-0 to 3 inches; dark grayish brown (10YR slightly hard, friable, slightly sticky and 4/2) gravelly silt loam, very dark brown slightly plastic; many roots ; many very (10YR 2/2) moist; weak thin and fine and fine pores; 35 percent gravel; medium platy structure parting to slightly acid; clear wavy boundary. moderate fine and medium granular; B1-7 to 14 inches; brown (10YR 5/3) gravelly slightly hard, friable, slightly sticky and loam, dark brown (10YR 4/3) moist; slightly plastic; many roots ; many very fine moderate fine and medium subangular and fine pores; 35 percent gravel ; neutral ; blocky structure ; slightly hard, friable, clear wavy boundary. slightly sticky and slightly plastic; many A12-3 to 7 inches; grayish brown (10YR 5/2) roots; many very fine and fine pores; 35 gravelly silt loam, very dark grayish percent gravel ; neutral; clear wavy boundary. B2t-14 to 20 inches ; pale brown (10YR 6/3)

gravelly heavy loam, dark brown (10YR Runoff is rapid, and the erosion hazard is high. 4/3) moist; moderate fine and medium Available water capacity is moderate. prismatic structure; slightly hard, This soil is used mainly for range and for wildlife friable, sticky and plastic; common habitat. Capability unit VIe-1; Loamy range site (L-3) roots; many fine and medium pores; many 100-Tekoa gravelly silt loam, 25 to 55 percent thin clay films on peds and in pores; 35 slopes. This moderately steep to very steep soil is on percent gravel ; neutral; clear wavy buttes. It has the profile described as representative of boundary. the series C1-20 to 38 inches; yellow (10YR 7/6) very Included with this soil in mapping are areas of gravelly loam, yellowish brown (10YR 5/6) Rock outcrop, soils that are less than 20 inches deep to moist; massive; slightly hard, friable, bedrock, Tekoa soils that have slopes of less than 25 slightly sticky and slightly plastic; few percent, soils that have a silt loam surface layer and a roots; 60 percent gravel; neutral; clear silty clay loam subsoil, stony or cobbly soils, and spots wavy boundary. of severely eroded soils. Cr-38 inches; unconsolidated metasediments. Runoff is rapid to very rapid, and the erosion hazard is high to very high. Available water capacity is moderate. Depth to the unconsolidated metasediments is 20 to This soil is used mainly for range and for wildlife 40 inches. The control section, between a depth of 10 habitat. Capability unit VIe-1 ; Loamy range site (L-3). inches and weathered metasediment, is 35 to 60 percent 101-Tekoa gravelly silt loam, deep, 25 to 55 percent coarse fragments. The profile has hue of 10YR or 7.5YR slopes. This moderately steep to very steep soil is on throughout. north- and east-facing sides of buttes. It has a profile Thickness of the A horizon is 6 to 9 inches. The A similar to the one described as representative of the horizon has value of 4 or 5 when dry and 2 or 3 when series, but the surface layer is 1 to 7 inches thicker and moist, and it has chroma of 2 or 3. Reaction is neutral the depth to unconsolidated metasediments is 40 to 60 or slightly acid. The B horizon has value of 5 or 6 inches. when dry and 3 or 4 when moist, and it has chroma Included with this soil in mapping are areas of of 3 or 4. It is silt loam or loam and is 35 to 60 percent Rock outcrop, soils that are less than 40 inches deep coarse fragments. Reaction is neutral or slightly acid. to unconsolidated metasediments, silt loams that are The C horizon has value of 5 to 7 when dry and 3 to 5 60 inches deep, and stony or cobbly soils. when moist, and it has chroma of 3 to 6. It is loam Runoff is rapid to very rapid, and the erosion hazard is or silt loam and has 35 to 70 percent coarse fragments. high or very high. The available water capacity is Reaction is neutral or slightly acid. moderately high. In Tekoa gravelly silt loam, deep, 25 to 55 percent This soil is used mainly for woodland, woodland slopes, the A horizon is thicker and depth to grazing, and wildlife habitat. Capability unit VIe-3. unconsolidated metasediment is greater than is defined 102-Tekoa stony silt loam, 25 to 40 percent slopes. in the range for the series. These differences do not This moderately steep to steep soil is on buttes. It has a significantly affect use and management. profile similar to the one described as representative of 98-Tekoa silt loam, 3 to 25 percent slopes. This the series, but the surface layer is 2 to 3 inches gently sloping to moderately steep soil is on foot slopes thicker and the surface is stony. of buttes. It has a profile similar to the one described Included with this soil in mapping are areas of Rock as representative of the series, but the surface layer is 3 outcrop, soils with no stones, cobbly soils; soils that to 4 inches thicker and has less gravel. have slopes less than 25 percent or more than 40 Included with this soil in mapping are areas of soils percent, and soils that have a silt loam surface layer that have slopes of more than 25 percent, Rock and silty clay loam or silty clay subsoil to a depth of outcrop, soils that are less than 20 inches deep to 60 inches. weathered metasediments, soils that are stony or cobbly, Runoff is rapid, and the erosion hazard is high. silt loams that are 40 to more than 60 inches deep to Available water capacity is moderate. bedrock, and soils that have a silt loam surface layer This soil is used mainly for range and for wildlife and a silty clay subsoil. habitat. Capability unit VIe-1; Loamy range site (L-3). Runoff is slow to medium, and the erosion hazard is slight to moderate. The available water capacity is Thatuna Series moderate. This soil is used mainly for wheat, barley, peas, The Thatuna series consists of gently sloping to lentils, grass, range, and wildlife habitat. Capability very steep, moderately well drained soils that formed in unit IVe-8; Loamy range site (L-3). loess and volcanic ash. These soils are on north- and 99-Tekoa silt loam, 25 to 40 percent slopes. This east-facing side slopes and south-facing foot slopes in the moderately steep to steep soil is on buttes. It has a northeastern part of the county. Elevation is 2,000 to profile similar to the one described as representative of 3,000 feet. The native vegetation is mainly Idaho the series, but the surface layer is 2 to 3 inches fescue, bluebunch wheatgrass, ninebark, and snowberry. thicker and has less gravel. The annual precipitation is 18 to 23 inches. The frost- Included with this soil in mapping are areas of Rock free season is 110 to 130 days. outcrop, soils that are less than 20 inches deep to bedrock, soils that are more than 40 inches deep to bedrock, stony or cobbly soils, and soils that have a silt loam surface layer and a silty clay loam subsoil.

fine and very fine pores; continuous thin In a representative profile the surface layer is dark clay films on peds and in pores; A2 grayish brown silt loam about 16 inches thick. The tongues of light brownish gray (10YR subsoil extends to a depth of 60 inches. It is brown 6/2) silt loam; common fine iron- silt loam to a depth of 33 inches and light brownish manganese concretions; slightly acid; clear gray silt loam to a depth of 39 inches. Below this, it is irregular boundary. pale brown and light yellowish brown silty clay loam. B'21t-45 to 50 inches; pale brown (10YR 6/3) Thatuna soils have moderate permeability above a silty clay loam, dark brown (10YR 4/3) depth of 39 inches and moderately slow permeability moist; moderate fine and medium below a depth of 39 inches. The available water subangular blocky structure; very hard, capacity is high. Roots penetrate to a depth of 60 very firm, sticky and plastic; few fine inches or more. Thatuna soils are used mainly for roots; many fine and very fine pores; wheat, barley, peas, lentils, grass, alfalfa, range, and continuous thin clay films on peds and in wildlife habitat. pores; few light brownish gray (10YR Representative profile of Thatuna silt loam, 7 to 25 6/2) coatings on peds; common fine iron- percent slopes, in an area of grassland, 200 feet west manganese concretions ; slightly acid; clear and 2,640 feet south of the northeast corner of sec. 11, irregular boundary. T. 19 N., R. 45 E.: B'22t-50 to 60 inches; light yellowish brown A11-0 to 8 inches; dark grayish brown (10YR (10YR 6/4) silty clay loam, dark yellowish 4/2) silt loam, very dark brown (10YR brown (10YR 4/4) moist; moderate fine 2/2) moist; moderate fine and medium and medium subangular blocky structure granular structure; slightly hard, very ; very hard, very firm, sticky and friable, slightly sticky and slightly plastic; plastic; few fine roots; many very fine many fine and very fine roots; many fine and fine pores ; continuous thin clay films and very fine pores; neutral; abrupt on peds and in pores; few light brownish smooth boundary. gray (10YR 6/2) coatings on peds; few A12-8 to 16 inches; dark grayish brown (10YR fine iron-manganese concretions; neutral; 4/2) silt loam, very dark brown (10YR clear wavy boundary. 2/2) moist; weak fine and medium prismatic structure; slightly hard, very The Al horizon has value of 4 or 5 when dry and 2 friable, slightly sticky and slightly plastic; or 3 when moist, and it has chroma of 1 to 3 when dry many fine and very fine roots; many fine and or moist. The A'2 and B'2t horizons contain few to very fine pores; neutral; clear wavy common iron-manganese concretions that are 1 to 3 boundary. millimeters in diameter. The B2 horizon has value of B21-16 to 21 inches; brown (10YR 5/3) silt loam, 4 or 5 when dry and 3 or 4 when moist. The B'&A' dark brown (10YR 3/3) moist; weak fine horizon, where present, and B'2t horizon have value and medium prismatic structure; hard, of 5 or 6 when dry and 3 or 4 when moist, and they firm, sticky and plastic; many fine and very have chroma of 3 or 4. The B2t horizon is heavy silt fine roots; many fine and very fine pores; loam or silty clay loam. The B2t horizon has thin, 5 to 10 percent wormholes partially patchy to thin, continuous clay films on peds and in filled with dark material from the A pores. Iron-manganese or organic staining occurs on horizon; neutral; clear wavy boundary. peds and varies from few to common. Reaction is B22-21 to 33 inches; brown (10YR 5/3) silt slightly acid to neutral throughout the profile. loam, dark brown (10YR 3/3) moist; 103-Thatuna silt loam, 3 to 7 percent slopes. This medium moderate prismatic structure gently sloping soil is on north- and east-facing foot parting to fine and medium subangular slopes. It has a profile similar to the one described as blocky; hard, firm, sticky and plastic; many representative of the series, but the surface layer is fine and very fine roots; many fine and very 2 to 3 inches thicker. fine pores; 5 to 10 percent wormholes Included with this soil in mapping are areas of soils partially filled with dark material from the that are silt loam to a depth of 60 inches, areas of soils A horizon; neutral ; gradual irregular that have slopes of more than 7 percent or less and 3 boundary. percent, and areas of soils that have a silt loam surface A'2-33 to 39 inches; light brownish gray (10YR layer and a silty clay subsoil. 6/3) silt loam, dark grayish brown (10YR Runoff is slow, and the erosion hazard is slight. This 4/2) moist; massive; slightly hard, very soil is saturated with water for short periods at a friable, slightly sticky and slightly plastic; depth of 18 to 40 inches. few fine roots; many very fine and fine This soil is used mainly for wheat, barley, peas, pores; common fine iron-manganese lentils, grass, and alfalfa. Capability unit IIe-3. concretions; slightly acid; clear irregular 104-Thatuna silt loam, 7 to 25 percent slopes. This boundary. strongly sloping to moderately steep soil is on north B'&A'-39 to 45 inches; pale brown (10YR 6/3) and east-facing side slopes and south-facing foot silty clay loam, dark brown (10YR 4/3) slopes. It has the profile described as representative of moist; moderate fine and medium prismatic the series. structure; very hard, very firm, sticky and Included with this soil in mapping are areas of soils plastic; few fine roots; many that are silt loam to a depth of 60 inches; spots of severely eroded soils, some of which are calcareous;

areas of soils that have a silt loam or silty clay loam 108-Thatuna-Tilma silt loams, 25 to 40 percent slopes. surface layer; areas of soils with a silty clay subsoil; These moderately steep to steep soils are on north- and areas of soils that have slopes of more than 25 and east-facing side slopes. This complex consists of 65 percent. percent Thatuna silt loam, 25 to 40 percent slopes, in Runoff is medium, and the erosion hazard is concave areas and 25 percent Tilma silt loam, 25 to 40 moderate. This soil is saturated with water for short percent slopes, in convex areas. The profiles of periods at a depth of 29 to 40 inches. Thatuna and Tilma soils are similar to the ones This soil is used mainly for wheat, barley, peas, described as representative of their respective series, lentils, grass, and alfalfa. Capability unit IIIe-4. but the surface layer of the Thatuna soil is 4 to 5 105-Thatuna silt loam, 25 to 40 percent slopes. This inches thicker and the surface layer of the Tilma soil is moderately steep to steep soil is on north- and east- 3 to 5 inches thinner. facing side slopes. It has a profile similar to the one Included with these soils in mapping are small areas described as representative of the series, but the surface of soils that are silt loam to a depth of 60 inches; areas layer is 4 to 5 inches thicker. of severely eroded soils, some of which are calcareous Included with this soil in mapping are areas of soils and some of which have a silty clay loam surface that are silt loam to a depth of 60 inches; areas of soils layer; areas of soils that have slopes of more than 40 that have a thin silt loam surface layer and a silty clay percent; and areas of soils that have a thin silt loam subsoil ; spots of severely eroded soils, some of which are surface layer and a silty clay loam subsoil. Included calcareous; areas of soils that have a thin surface laver areas make up about 10 percent of the mapped acreage. of silt loam or silty clay loam; and areas of soils that Runoff is rapid, and the hazard of erosion is high. have slopes of more than 40 percent. These soils are saturated with water for short periods Runoff is rapid, and the erosion hazard is high. This soil at a depth of 18 to 40 inches. is saturated with water for short periods at a depth of These soils are used mainly for wheat, barley, peas, 29 to 40 inches. lentils, grass, and alfalfa. Capability unit IVe-5. This soil is used mainly for alfalfa, grass, wheat, 109-Thatuna-Naff silt loams, 7 to 25 percent slopes. barley, peas, and lentils. Capability unit IVe-4. These strongly sloping to moderately steep soils are 106-Thatuna silt loam, 40 to 55 percent slopes. This on foot slopes and north-facing side slopes. This steep to very steep soil is on north- and east-facing complex consists of 70 percent Thatuna silt loam, 7 to side slopes. 25 percent slopes, in concave areas and 25 percent Included with this soil in mapping are areas of soils Naff silt loam, 7 to 25 percent slopes, in convex areas that have a thin silt loam surface layer and a silty that are generally on knobs and narrow ridges. clay loam subsoil; soils that have a silty clay subsoil; Included with these soils in mapping are areas of severely eroded soils, some of which are calcareous and soils that are silt loam to a depth of 60 inches; spots of some of which have a silty clay loam surface layer; severely eroded soils, some of which are calcareous; areas soils that are silt loam to a depth of 60 inches; soils in of soils that have a silty clay subsoil; and areas of narrow, steep or very steep, semicircular areas, or soils that have slopes of more than 25 percent. An eyebrows; and soils that have slopes of less than 40 eroded spot symbol is used on some knobs and ridges. percent. Included areas make up about 5 percent of the mapped Runoff is very rapid, and the erosion hazard is very acreage. high. This soil is saturated with water for short periods Runoff is medium, and the hazard of erosion is moderate. at a depth of 29 to 40 inches. The Thatuna soil is saturated with water for short This soil is used mainly for range and for wildlife periods at a depth of 29 to 40 inches. habitat. Capability unit VIe-1; North exposure range These soils are used mainly for wheat, barley, peas, site (N-3). lentils, grass, and alfalfa. Capability unit IIIe-5. 107-Thatuna-Tilma silt loams, 7 to 25 percent slopes. These strongly sloping to moderately steep soils are on Tilma Series north- and east-facing side slopes and south-facing foot slopes. This complex consists of 65 percent Thatuna silt The Tilma series consists of gently sloping to steep, loam, 7 to 25 percent slopes, in concave areas and 25 moderately well drained soils that formed in loess and percent Tilma silt loam, 7 to 25 percent slopes, in convex some volcanic ash underlain by finer textured older loess. areas. These soils are on uplands in the northeastern part of Included with these soils in mapping are areas of the county. Elevation is 1,800 to 3,000 feet. The native soils that are silt loam to a depth of 60 inches small vegetation is Idaho fescue, bluebunch wheatgrass, and areas on knobs and ridgetops of severely eroded soils, some snowberry. The annual precipitation is 18 to 23 inches. of which are calcareous and some of which have a silty clay The frost-free season is 110 to 130 days. loam surface layer; areas of soils that have a thin silt In a representative profile the surface layer is dark loam surface layer and a silty clay loam subsoil; and grayish brown and grayish brown silt loam about 14 areas of soils that have slopes of more than 25 percent. inches thick. The subsoil extends to a depth of 60 Included areas make up about 10 percent of the mapped inches. It is grayish brown silt loam to a depth of acreage. 18 inches and light brownish gray silt loam to a Runoff is medium, and the hazard of erosion is moderate. depth of 21 inches; below this it is pale brown and These soils are saturated with water for short periods very pale brown silty clay and silty clay loam (fig. 18). at a depth of 18 to 40 inches. These soils are used Tilma soils have moderate permeability above a mainly for wheat, barley, peas, lentils, grass. and alfalfa. depth of 18 to 30 inches and slow permeability below a Capability unit IIIe-5. depth of 18 to 30 inches. The available water capacity

sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; slightly acid; abrupt smooth boundary. A1-8 to 14 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; neutral ; clear wavy boundary. B2-14 to 18 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to moderate subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; neutral ; clear wavy boundary. A'2-18 to 21 inches ; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few roots; many very fine and fine pores; few fine iron-manganese concretions; neutral; abrupt smooth boundary. B'21t-21 to 35 inches; pale brown (10YR 6/3) silty clay, brown (10YR 4/3) moist; ped faces dark brown (7.5YR 3/3) moist; fades when exposed to air; strong medium and coarse subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few fine roots; many fine and very fine tubular pores; continuous moderately thick clay films on peds and in pores; many fine to very fine iron-manganese concretions; neutral; clear wavy boundary. B'22t-35 to 40 inches; pale brown (10YR 6/3) silty clay, brown (10YR 4/3) moist; ped faces dark brown (7.5YR 3/3) moist; fades when exposed to air; strong medium and coarse subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; many very fine and fine pores; continuous moderately thick clay films on peds and in pores; common fine and very fine iron- manganese concretions; common gray coatings on peds ; neutral; clear wavy boundary. Figure 18.-Profile of Tilma silt loam, 7 to 25 percent slopes. B'3-40 to 60 inches; very pale brown (10YR 7/3) An abrupt, smooth boundary is at a depth of about 3 feet. silty clay loam, brown (10YR 5/3) moist; strong medium and coarse subangular is moderately high or high. Root penetration is blocky structure; very hard, very firm, somewhat limited by the silty clay layer in the lower sticky and plastic ; many very fine and fine part of the subsoil, but some roots extend to a depth of pores; continuous thin clay films on peds 60 inches or more. Tilma soils are used mainly for wheat, and in pores; few fine and very fine iron- barley, peas, lentils, grass, and alfalfa. manganese concretions; many gray coatings Representative profile of Tilma silt loam, 7 to 25 on peds; mildly alkaline. percent slopes, in a cultivated area, 1,000 feet north and 400 feet west of the southeast corner of sec. 25, T. Thickness of the Ap and A1 horizons is 10 to 20 15 N., R. 45 E.: inches. They have value of 4 or 5 when dry and 2 or 3 Ap-0 to 8 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate medium granular structure ; slightly hard, friable, slightly when moist, and they have chroma of 1 or 2 when dry or underlying basalt. They are on uplands that border moist. The B2 horizon has value of 4 or 5 when dry and 2 steep side slopes along drainageways in channeled or 3 when moist, and it has chroma of 2 or 3. The A'2 scablands in the northwestern part of the county. Ele horizon has value of 5 or 6 when dry and 3 or 4 when vation is 1,800 to 3,000 feet. The native vegetation is moist, and it has chroma of 2. It has few fine or mainly bluebunch wheatgrass and Idaho fescue. The common fine iron-manganese concretions. Depth to the B'2t annual precipitation is 16 to 23 inches. The frost-free horizon is 18 to 30 inches. The B'2t horizon is 35 to 45 season is 110 to 130 days. percent clay. It has value of 5 or 6 when dry and 3 or 4 In a representative profile the surface layer is dark when moist, chroma of 3 or 4, and hue of 7.5YR or grayish brown and grayish brown silt loam about 13 10YR. It contains few to many fine and very fine iron- inches thick. The upper part of the subsoil, to a depth manganese concretions. Clay films range from thin patchy of 26 inches, is brown and pale brown silt loam. The to moderately thick and continuous. In some pedons the lower part, to a depth of 30 inches, is pale brown B'2t horizon has few to many gray coatings on peds. The gravelly silt loam. It is underlain by basalt bedrock. B'3 horizon has value of 6 or 7 when dry and 4 or 5 There are basalt fragments larger than 2 millimeters when moist, and it has chroma of 3 or 4. throughout the soil; the amount increases with depth. 110-Tilma silt loam, 3 to 7 percent slopes. This gently Tucannon soils have moderate permeability. The sloping soil is on uplands. It has a profile similar to the one available water capacity is moderate and moderately described as representative of the series, but the surface high. Roots penetrate to bedrock. Tucannon soils are layer is 2 to 3 inches thicker. used mainly for wheat, barley, peas, lentils, grass, Included with this soil in mapping are areas of soils that alfalfa, range, and wildlife habitat. are silty clay loam at a depth of 40 inches, soils that Representative profile of Tucannon silt loam, 7 to are silt loam to a depth of 60 inches, somewhat poorly 25 percent slopes, in a cultivated area, 170 feet west drained soils, and severely eroded soils. and 250 feet north of the southeast corner of sec. 29, Runoff is slow, and the erosion hazard is slight. This T. 17 N., R. 44 E.: soil is saturated with water for short periods above the Ap-0 to 8 inches; dark grayish brown (10YR slowly permeable subsoil. 4/2) silt loam, very dark brown (10YR This soil is used mainly for wheat, barley, peas, 2/2) moist; moderate fine and medium lentils, grass, and alfalfa. Capability unit IIIe-5. granular structure; slightly hard, friable, 111-Tilma silt loam, 7 to 25 percent slopes. This slightly sticky and slightly plastic; many strongly sloping to moderately steep soil is on uplands. It fine roots; common fine pores; slightly has the profile described as representative of the series. acid; abrupt smooth boundary. Included with this soil in mapping are areas of soils that A3-8 to 13 inches; grayish brown (10YR 5/2) have a silty clay loam subsoil below a depth of 40 silt loam, very dark grayish brown (10YR inches, soils that are silt loam to a depth of 60 inches, 3/2) moist; weak fine and medium and somewhat poorly drained soils. prismatic structure parting to weak fine Runoff is medium, and the hazard of erosion is moderate. and medium subangular blocky; slightly This soil is saturated with water for short periods above hard, friable, slightly sticky and slightly the silty clay layer in the lower part of the subsoil. plastic; common fine and very fine roots; This soil is used for wheat, barley, lentils, peas, common very fine pores; neutral; clear grass, and alfalfa. Capability unit IIIe-5. wavy boundary. 112-Tilma silt loam, 25 to 40 percent slopes. This B21-13 to 22 inches; brown (10YR 5/3) silt moderately steep and steep soil is on uplands. It has a loam, dark brown (10YR 3/3) moist; profile similar to the one described as representative of moderate fine and medium prismatic the series, but the surface layer is 3 to 5 inches structure parting to moderate fine and thinner. medium blocky; hard, friable, slightly Included with this soil in mapping are areas of soils sticky and plastic; common fine roots ; that are silty clay loam below a depth of 40 inches,. common very fine pores; few thin clay silt loams that are 60 inches deep, soils that have a films on some ped surfaces; neutral; silty clay loam surface layer and subsoil, and severely clear wavy boundary. eroded soils. B22-22 to 26 inches; pale brown (10YR 6/3) Runoff is rapid, and the erosion hazard is high. This soil silt loam, dark brown (10YR 4/3) moist; is saturated with water for short periods above the weak fine and medium prismatic structure silty clay layer in the lower part of the subsoil. parting to moderate fine and medium This soil is used mainly for wheat, barley, peas, subangular blocky; hard, friable, slightly lentils, grass, and alfalfa. Capability unit IVe-5. sticky and plastic; common fine roots; many fine pores; few thin patchy clay films on Tucannon Series ped faces and in pores; neutral; clear wavy boundary. The Tucannon series consists of nearly level to B3-26 to 30 inches; pale brown (10YR 6/3) moderately steep, well drained soils underlain by basalt gravelly silt loam, brown (10YR 4/3) bedrock at a depth of 20 to 40 inches. These soils moist; massive; slightly hard, friable, formed in loess and some volcanic ash and weathered slightly sticky and slightly plastic; few fine roots; common fine and medium pores; 20 percent gravel and cobbles;

neutral; clear wavy boundary. of 60 inches or more. Uhlig soils are used mainly for IIR-30 inches ; basalt. wheat, barley, and peas. Representative profile of Uhlig silt loam, 7 to 15 Basalt is at a depth of 20 to 40 inches. The control percent slopes, in a cultivated area, 95 feet west and section, between a depth of 10 inches and bedrock, is 18 2,500 feet south of the northeast corner of sec. 3, T. 19 to 25 percent clay. It is 5 to 25 percent coarse basalt N., R. 40 E.: fragments in places. The profile is slightly acid to Ap-0 to 8 inches; dark grayish brown (10YR neutral throughout. 4/2) silt loam, very dark brown (10YR Thickness of the A horizon is 12 to 18 inches. The A 2/2) moist; weak fine and medium granular horizon has value of 4 or 5 when dry and 2 or 3 structure; slightly hard, friable, slightly when moist. The B horizon has value of 5 or 6 when sticky and slightly plastic; many roots; many dry and 3 or 4 when moist, and it has chroma of 2 or 3. very fine and fine pores; slightly acid; abrupt 113-Tucannon silt loam, 7 to 25 percent slopes. smooth boundary. This strongly sloping to moderately steep soil is on A1-8 to 15 inches; dark grayish brown (10YR uplands that border steep side slopes of major 4/2) silt loam, very dark brown (10YR drainageways. It has the profile described as 2/2) moist; weak fine prismatic structure; representative of the series. slightly hard, friable, slightly sticky and Included with this soil in mapping are areas of soils slightly plastic; many roots ; many very that have bedrock at a depth of less than 20 inches, fine and fine pores; neutral ; clear wavy soils that are more than 60 inches deep, and Rock boundary. outcrop. A12-15 to 21 inches; dark grayish brown (10YR Runoff is medium, and the hazard of erosion is 4/2) silt loam, very dark brown (10YR 2/2) moderate. moist; weak fine and medium prismatic This soil is used mainly for wheat, barley, peas, structure; slightly hard, friable, slightly lentils, grass, alfalfa, range, and wildlife habitat. sticky and slightly plastic; many roots; Capability unit IVe-12 ; Loamy range site (L-3). common fine and medium pores; neutral ; 114-Tucannon-Bakeoven complex, 0 to 30 percent clear wavy boundary. slopes. These nearly level to moderately steep soils are on B1-21 to 30 inches; brown (10YR 5/3) silt loam, side slopes along drainageways. This complex consists dark brown (10YR 3/3) moist; weak of 40 percent Tucannon silt loam, 7 to 25 percent slopes, medium prismatic structure; slightly hard, and 30 percent Bakeoven very cobbly loam that has slopes friable, slightly sticky and slightly plastic; of 0 to 30 percent. many roots; common fine and medium Included with these soils in mapping are areas of pores; mildly alkaline; clear wavy soils that have bedrock at a depth of less than 20 boundary. inches ; deep, very stony soils on colluvial slopes; Rock B2-30 to 41 inches ; brown (10YR 5/3) loam, dark outcrop ; soils that are 20 to 40 inches deep to gravel brown (10YR 3/3) moist; weak medium and cobbles; and somewhat poorly drained soils in de- prismatic structure; soft, slightly hard, pressions. Included areas make up about 30 percent of friable, slightly sticky and slightly plastic; the mapped acreage. common roots; common very fine and fine Runoff is very slow to medium, and the erosion hazard is pores; mildly alkaline ; clear wavy boundary. slight or moderate. C1-41 to 55 inches; brown (10YR 5/3) loam, This soil is used mainly for range and for wildlife dark brown (10YR 4/3) moist; massive; habitat. Capability unit VIs-1; Tucannon part in Loamy slightly sticky and slightly plastic; com- range site (L-3), Bakeoven part in Very Shallow range mon roots; very fine and fine pores; 1to site. 11/2-inch lenses of sand and gravel; mildly alkaline; clear wavy boundary. Uhlig Series C2-55 to 60 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 4/3) moist; The Uhlig series consists of strongly sloping, well massive; soft, very friable, slightly sticky drained soils that formed in glacial outwash mixed in the and slightly plastic; few roots; very fine upper part with loess and some volcanic ash. The soils and fine pores; mildly alkaline. are on terraces in the northwestern part of the county. Elevation is 1,800 to 2,300 feet. The native vegetation The control section, between depths of 10 and 40 is mainly bluebunch wheatgrass, Idaho fescue, and inches, averages less than 18 percent clay. snowberry. The annual precipitation is 17 to 19 inches. Thickness of the A horizon is 20 to 30 inches. The A The frost-free season is 130 to 140 days. horizon has value of 2 or 3 when moist and 4 or 5 when In a representative profile the surface layer is dark dry, and it has chroma of 1 or 2 when moist or dry. grayish brown silt loam about 21 inches thick. The The B horizon has value of 3 or 4 when moist and 5 upper part of the subsoil, to a depth of 30 inches, is or 6 when dry, and it has chroma of 3 or 4 when brown silt loam. The lower part, to a depth of 41 moist or dry. The C horizon has value of 3 or 4 when inches, is brown loam. The substratum, to a depth of 60 moist and 5 or 6 when dry, and it has chroma of 3 inches, is brown loam and fine sandy loam. A few when moist or dry. gravel- and cobble-size fragments are in places on the 115 -Uhlig silt loam, 7 to 15 percent slopes. This surface and throughout the profile. strongly sloping soil is on terraces. Uhlig soils have moderate permeability. The available water capacity is high. Roots penetrate to a depth

Included with this soil in mapping are areas of soils tubular pores; mildly alkaline; clear that are silt loam to a depth of 60 inches and areas of wavy boundary. soils that are 20 to 40 inches deep to gravel, cobbles, C-41 to 60 inches; pale brown (10YR 6/3) silt or basalt. loam, dark brown (10YR 4/3) moist ; Runoff is medium, and the erosion hazard is mod- massive; slightly hard, friable, slightly erate. sticky and slightly plastic; common This soil is used mainly for wheat, barley, and peas. roots; mildly alkaline. Capability unit IIIe-3. Depth to secondary carbonates is 43 to more than 60 Walla Walla Series inches. The control section, between depths of 10 and 40 inches, is less than 18 percent clay. The Walla Walla series consists of gently sloping to Thickness of the A horizon is 10 to 16 inches. The A very steep, well drained soils that formed in loess and horizon has value of 4 or 5 when dry and 2 or 3 some volcanic ash. The soils are on uplands in the when moist. The B horizon has value of 5 or 6 when southwestern part of the county. Elevation is 1,200 to dry and 3 or 4 when moist. The C horizon has value of 5 2,200 feet. The native vegetation is mainly bluebunch or 6 when dry and 3 or 4 when moist. The soil is wheatgrass and Idaho fescue. The annual precipitation is neutral in the A horizon, neutral to mildly alkaline in the B 12 to 15 inches. The frost-free season is 130 to 155 horizon, and mildly alkaline to strongly alkaline in the C days. horizon. In a representative profile the surface layer is dark 116-Walla Walla silt loam, 3 to 7 percent slopes. This grayish brown and grayish brown silt loam about 16 gently sloping soil is on uplands. It has a profile similar to inches thick. The subsoil, to a depth of 41 inches, is the one described as representative of the series, but the brown and pale brown silt loam. The substratum, to a surface layer is 2 to 3 inches thicker. depth of 60 inches, is pale brown silt loam. Included with this soil in mapping are areas of soils that Walla Walla soils have moderate permeability. The have slopes of more than 7 percent and soils that have available water capacity is high. Roots penetrate to a a lime-silica hardpan at a depth of 20 to 40 inches. depth of 60 inches or more. Walla Walla soils are used Also included are circular areas called slick spots. mainly for wheat, barley, alfalfa, grass, range, and Runoff is slow, and the erosion hazard is slight. wildlife habitat. This soil is used mainly for wheat, barley, range, and Representative profile of Walla Walla silt loam, 7 to 25 wildlife habitat. Capability unit IIe-1; Loamy range percent slopes, in an area of grassland, 700 feet west site (L-2). of the southeast corner of sec. 33, T. 15 N., R. 40 E.: 117-Walla Walla silt loam, 7 to 25 percent slopes. This A11-0 to 5 inches; dark grayish brown (10YR strongly sloping to moderately steep soil is on uplands. 4/2) silt loam, very dark brown (10YR It has the profile described as representative of the series. 2/2) moist; weak fine granular structure; Included with this soil in mapping are areas of soils that slightly hard, very friable, slightly sticky have slopes of more than 25 percent; spots, ridges, and and slightly plastic; many roots; neutral; knobs of severely eroded soils; areas of soils that have abrupt smooth boundary slopes of less than 7 percent; and areas of soils that A12-5 to 16 inches; grayish brown (10YR 5/2) have a lime-silica hardpan at a depth of 20 to 40 silt loam, very dark grayish brown (10YR inches. Also included are circular areas called slick 3/2) moist; weak medium subangular spots. blocky structure; slightly hard, friable, Runoff is medium, and the erosion hazard is slightly sticky and slightly plastic ; many moderate. roots; few fine tubular pores; neutral; clear This soil is used mainly for wheat, barley, range, wavy boundary. and wildlife habitat. Capability unit IIIe-2; Loamy range B1-16 to 23 inches; brown (10YR 5/3) silt loam, site (L-2). dark brown (10YR 4/3) moist; weak 118-Walla Walla silt loam, 15 to 30 percent slopes, medium prismatic structure; slightly hard, eroded. This moderately steep soil is on uplands. It has a friable, slightly sticky and slightly plastic; profile similar to the one described as representative of the common roots; few fine tubular pores ; series, but 8 to 10 inches of the original surface layer has mildly alkaline; clear wavy boundary. been removed by erosion. B2-23 to 31 inches; brown (10YR 5/3) silt loam, Included with this soil in mapping are concave areas of dark brown (10YR 4/3) moist; weak soils that have a surface layer 10 to more than 18 medium prismatic structure; slightly hard, inches thick, areas on ridgetops and knobs of soils that friable, slightly sticky and slightly plastic; have a calcareous surface layer, and areas of soils that common roots; few fine tubular pores; have a lime-silica hardpan at a depth of 20 to 40 inches. neutral; clear wavy boundary. Also included are circular areas called slick spots. B3-31 to 41 inches; pale brown (10YR 6/3) silt Runoff is medium to rapid, and the erosion hazard is loam, brown (10YR 4/3) moist; weak moderate or high. medium and coarse prismatic structure ; This soil is used mainly for wheat, alfalfa, and grass. slightly hard, friable, slightly sticky and Capability unit IVe-2. slightly plastic; common roots; few fine 119-Walla Walla silt loam, 25 to 40 percent slopes. This moderately steep soil is on uplands. It has a pro- file similar to the one described as representative of Ap-0 to 6 inches; grayish brown (10YR 5/2) silt the series, but the surface layer is 2 to 3 inches thinner. loam, very dark brown (10YR 3/2) moist; Included with this soil in mapping are areas of weak fine granular structure; soft, very volcanic ash; spots of severely eroded soils, some of friable, nonsticky and nonplastic; many which are calcareous; areas on ridgetops and knobs of fine tubular pores ; many very fine roots; soils that have a thin surface layer; and areas of soils neutral; abrupt smooth boundary. that have slopes of more than 40 percent. A1-6 to 14 inches; grayish brown (10YR 5/2) silt Runoff is rapid, and the erosion hazard is high. loam, very dark grayish brown (10YR 3/2) This soil is used mainly for wheat, alfalfa, grass, moist; weak fine and medium subangular range, and wildlife habitat. Capability unit IVe-2; blocky structure; soft, very friable, Loamy range site (L-2). nonsticky and nonplastic ; few very fine 120-Walla Walla silt loam, 30 to 40 percent slopes, roots; many fine tubular pores; neutral ; eroded. This steep soil is on uplands. It has a profile gradual wavy boundary. similar to the one described as representative of the C1-14 to 27 inches; brown (10YR 5/3) very fine series, but 8 to 10 inches of the original surface layer sandy loam, dark brown (10YR 4/3) has been removed by erosion. moist; massive; soft, very friable, Included with this soil in mapping are concave areas nonsticky and nonplastic; few very fine of soils that have a surface layer 10 to more than 18 roots; many fine tubular pores; neutral ; inches thick, soils that have a calcareous surface layer, gradual wavy boundary. soils that have slopes of more than 40 percent, and C2-27 to 40 inches; pale brown (10YR 6/3) fine soils that have slopes of less than 30 percent. sandy loam, dark brown (10YR 4/3) Runoff is rapid, and the erosion hazard is high. moist; massive; soft, very friable, This soil is used mainly for wheat, barley, alfalfa, nonsticky and nonplastic ; common fine and grass. Capability unit VIe-2. tubular pores; few very fine roots; mildly 121-Walla Walla silt loam, 40 to 55 percent slopes. alkaline; clear smooth boundary. This steep to very steep soil is generally on north- C3ca-40 to 60 inches; very pale brown (10YR facing side slopes on uplands. It has a profile similar to 7/3) silt loam, brown (10YR 5/3) moist ; the one described as representative of the series, but the massive; slightly hard, friable, slightly surface layer is 3 to 4 inches thinner. sticky and slightly plastic; few very fine Included with this soil in mapping are spots of roots; common fine tubular pores; strongly severely eroded soils, some of which are calcareous; effervescent; moderately alkaline. areas on ridges and knobs of soils that have a thin surface layer; and spots of volcanic ash. Thickness of the A horizon is 10 to 20 inches. The Runoff is very rapid, and the erosion hazard is very A horizon has value of 4 or 5 when dry and 2 or 3 high. when moist, and it has chroma of 2 or 3. The C horizon This soil is used mainly for range and for wildlife has value of 5 to 7 when dry and 4 or 5 when moist. It habitat. Capability unit VIe-1; North exposure range is silt loam, very fine sandy loam, or fine sandy loam. site (N-1). It is neutral to mildly alkaline to a depth of 40 inches and is moderately alkaline at a depth of more than 40 Walvan Series inches. 122-Walvan silt loam, 7 to 25 percent slopes. This The Walvan series consists of strongly sloping to strongly sloping to moderately steep soil is on uplands. moderately steep, well drained soils that formed in Included with this soil in mapping are areas of soils that loess and volcanic ash. The soils are on east- and north- are silt loam to a depth of 60 inches, soils that have facing side slopes of uplands in the southwestern part slopes of more than 25 percent, and soils that have slopes of of the county. less than 7 percent. Elevation is 1,200 to 2,200 feet. The native vegetation Runoff is medium. The erosion hazard is moderate, and is mainly bluebunch wheatgrass and Idaho fescue. The the soil blowing hazard is high. annual precipitation is 12 to 15 inches. The frost-free This soil is used mainly for wheat, alfalfa, grass, season is 130 to 150 days. range, and wildlife habitat. Capability unit IVe-9 ; In a representative profile the surface layer is gray- Loamy range site (L-2). ish brown silt loam about 14 inches thick. The under- lying material is brown very fine sandy loam to a Xerofluvents depth of 27 inches, pale brown fine sandy loam to a depth of 40 inches, and very pale brown silt loam to a 123-Xerofluvents, 0 to 15 percent slopes. Xerofluvents depth of 60 inches. are deep, somewhat excessively drained and excessively Walvan soils have moderate permeability. The available drained, nearly level to strongly sloping soils that formed water capacity is high. Roots penetrate to a depth of 60 in cobbly alluvium. These soils are on bottom lands, inches or more. Walvan soils are used mainly for wheat, terraces, and alluvial fans along the Snake and Palouse alfalfa, grass, range, and wildlife habitat. Rivers. They are stratified very cobbly sand, very Representative profile of Walvan silt loam, 7 to 25 gravelly coarse sand, or very stony coarse sand to a percent slopes, in a cultivated area, 2,200 feet west and depth of 60 inches. These soils are subject to flooding 1,500 feet north of the southeast corner of sec. 26, T. in winter and in spring. Vegetation 14 N., R. 37 E.:

and helps to reduce evaporation loss. If a stubble mulch- is sparse willows, shrubs, and grasses. Mean annual fallow system is properly managed, crop residue is precipitation is 11 to 18 inches. Mean annual air mixed in the tillage layer, and at least 2,000 pounds of temperature is about 50° F, and the frost-free season the residue is on the surface at seeding time. is 150 to 160 days. Tillage operations should be kept to the minimum These soils have value for wildlife habitat, for necessary to control weeds and prepare a suitable seedbed. recreational areas, and for esthetic purposes. Capability Also important is the careful operation of tillage unit VIIIw-1. implements and tilling only when the soil is not too wet or too dry. Commercial fertilizers are used commonly and Use and Management of the Soils should be applied according to soil tests, field trials, and crop needs. Fertilizers help to produce a good This section contains information about the use and protective cover and make possible the full use of all management of the soils in the survey area for crops available moisture. and pasture, range, woodland, windbreaks, wildlife Field diversions and terraces are helpful in habitat, and engineering. It explains the system of controlling erosion and increasing water intake rates in capability classification used by the Soil Conservation some areas. They are designed either to intercept Service and gives estimated yields of the principal crops. surface runoff and hold the water in place until it infiltrates or carry it off the slope at a slow rate to a Crops and pasture place where it can be disposed of safely. Level terraces are suitable on deep silt loams that have less than 6 Agriculturally, the survey area is divided into two percent slopes. Gradient terraces or diversions are used major areas: the eastern and the western. Each area on soils that have 6 to 15 percent slopes. All such has conservation problems peculiar to it, and a different diversions must have protected outlets, and emergency kind of farming must be developed for each. outlets are advisable for level terraces. Drop structures The eastern area is one of large farms and deep soils and debris basins or sediment traps should be used in that are used for dryland crops. Controlling erosion is the conjunction with most terraces and diversion systems. major conservation concern, especially on most cultivated Careful design and construction are necessary. soils. Controlling weeds and maintaining fertility and Grassed waterways are needed in field draws to prevent organic matter are also concerns. gullying caused by runoff. They also can serve as outlets Rain and melting snow often cause excessive runoff and for gradient terraces and diversions. severe erosion, particularly when the surface layer is Cross-slope farming is an effective method of reducing frozen. On the steepest soils, surface soil is moved down runoff and controlling erosion. On long slopes, planting slope with each tillage operation. crops in transverse strips prevents the exposure of the Most of the soils in the area are high in content of entire slope to runoff at any one time. Stripcropping, organic matter and have good tilth. However, eroded cover vegetation, and crops planted in alternate bands soils have less organic matter in the surface laver, reduce soil loss on long slopes. absorb water more slowly, store less moisture, and are Where the slope and topography do not permit cropping more susceptible to erosion. Crop residue, fertilizer, and in multiple strips, half of the slope can be planted to green manure crops are needed to maintain organic- protective cover vegetation and half to a crop. This matter content, fertility, and good tilth on these soils. method is called "divided-slope farming." For best results, The cropping systems generally used in the area are strips should be as nearly on the contour as practical. (1) wheatpeas or lentils, (2) annual grains, and (3) The western area consists of large farms, deep soils, and grass for seed. Combinations and variations of these channeled scablands. These soils are used mainly for grain systems are also practiced, including rotation with farming and livestock operations. Precipitation in much grasses and legumes and in some cases summer fallow. of this area is slightly less than is needed to make Returning all crop residue to the soil helps to annual cropping consistently practical. The most maintain the organic-matter content at a desirable practical cropping system is one in which winter grains level. Tillage equipment has been improved in recent years alternate with stubble mulch-fallow. This system to make residue easier to use. Also, shorter strawed necessitates special attention to control erosion. varieties of grain have been developed, and commercial Conservation benefits can be obtained by adding a fertilizers are now available that make it possible to rotation of alfalfa and grass to the system. use large amounts of residue and still maintain Runoff interception and water disposal are suitable for economic yields. some of the cropland, where slopes are less than 20 Where annual cropping of grain is practical, the percent. Grassed waterways are needed as outlets for residue should be mixed throughout the tillage layer of diversion terraces or gradient terraces and for the the soil. Plowing under residue in a layer or leaving too control of gully erosion in field draws. Many of the slopes much residue on the surface impedes water intake, root are suitable for contour farming or field stripcropping. penetration, and plant growth. Peas and lentil vines are Strips of grain fallow should alternate with strips of best utilized when left on the surface. alfalfa and grass. At least 2,000 pounds of residue Where summer fallow is used, crop residue should be left should be left on the surface at seeding time. Minimum on the surface, where it provides maximum protection tillage during the fallow season helps to control against erosion, increases water intake rate, pulverization of the soil. Application of fertilizer in accordance with soil tests, field trials, and crop

letter e shows that the main limitation is risk of erosion needs makes possible the efficient use of available soil unless close-growing plant cover is maintained; w shows moisture and produces a good protective cover. During that water in or on the soil interferes with plant growth seasons when there is favorable moisture and soils hold or cultivation (in some soils the wetness can be partly a good supply of it, annual cropping is preferable to corrected by artificial drainage) ; s shows that the soil is alternate cropping and fallow. limited mainly because it is shallow, droughty, or stony; and c, used in only some parts of the United Capability grouping States, shows that the chief limitation is climate that is Capability grouping shows, in a general way, the too cold or too dry. suitability of soils for most kinds of field crops. The In class I there are no subclasses, because the soils of groups are made according to the limitations of the this class have few limitations. Class V can contain, at soils when used for field crops, the risk of damage when the most, only the subclasses indicated by w, s, and c, they are used, and the way they respond to treatment. because the soils in class V are subject to little or no The grouping does not take into account major and erosion, though they have other limitations that generally expensive landforming that would change restrict their use largely to pasture, range, woodland, slope, depth, or other characteristics of the soils; does wildlife habitat, or recreation. not take into consideration possible but unlikely major CAPABILITY UNITS are soil groups within the reclamation projects; and does not apply to horticultural subclass. The soils in one capability unit are enough alike crops or other crops that require special management. to be suited to the same crops and pasture plants, to Those familiar with the capability classification can require similar management, and to have similar infer from it much about the behavior of soils when productivity and other responses to management. Thus, used for other purposes, but this classification is not a the capability unit is a convenient grouping for making substitute for interpretations designed to show many statements about management of soils. suitability and limitations of groups of soils for range, Capability units are generally designated by adding an for forest trees, or for engineering. Arabic numeral to the subclass symbol, for example, In the capability system, all kinds of soil are grouped IIe-3 or IIIe-6. Thus, in one symbol, the Roman at three levels: the capability class, subclass, and unit. numeral designates the capability class, or degree of These are explained in the following paragraphs. limitation ; the small letter indicates the subclass, or CAPABILITY CLASSES, the broadest groups, are kind of limitation, as defined in the foregoing designated by Roman numerals I through VIII. The paragraph; and the Arabic numeral specifically identifies numerals indicate progressively greater limitations and the capability unit within each subclass. narrower choices for practical use, defined as follows In the following pages the capability units in Whitman Class I soils have few limitations that restrict their County are described and suggestions for the use and use. management of the soils are given. Class II soils have moderate limitations that reduce The capability unit to which each soil has been the choice of plants or that require moderate assigned is given, with the range site, in the mapping unit conservation practices. description in the section "Descriptions of the Soils." Class III soils have severe limitations that reduce CAPABILITY UNIT IIe-1 the choice of plants, require special conservation This unit consists of well drained Chard and Walla practices, or both. Walla soils. These soils are more than 60 inches deep. Class IV soils have very severe limitations that Slopes range from 3 to 7 percent. Permeability is reduce the choice of plants, require very careful moderate to moderately rapid, and the available water management, or both. capacity is high. Surface runoff is slow, and the erosion Class V soils are not likely to erode but have other hazard is slight. The annual precipitation ranges from 12 limitations, impractical to remove, that limit their to 15 inches. The frost-free season is 130 to 155 days. use largely to pasture, range, woodland, or Wheat, barley, alfalfa, and grass are the principal wildlife habitat. crops. These soils are generally farmed in a wheat- Class VI soils have severe limitations that make fallow rotation, or 2 years of wheat followed by 1 year them generally unsuited to cultivation and limit of fallow. In some years the moisture supply is too low their use largely to pasture or range, woodland, for annual cropping. or wildlife habitat. These soils can be farmed without excessive erosion if Class VII soils have very severe limitations that waterways are shaped, packed, and seeded to grass; make them unsuited to cultivation and that restrict crop residue is mixed into the tillage layer ; maximum their use largely to pasture or range, woodland, residue of straw is left on the surface at seeding time; or wildlife habitat. tillage is across the slopes; and fall grain is seeded Class VIII soils and landforms have limitations early enough to provide winter cover. If no winter cover that preclude their use for commercial plants and crop is grown and no stubble is left standing, the restrict their use to recreation, wildlife habitat, surface is kept rough and cloddy. Terraces, diversions, and water supply, or esthetic purposes. stripcropping are needed to help control erosion on long CAPABILITY SUBCLASSES are soil groups within slopes that have no grass and legume cover. Chiseling in one class; they are designated by adding a small fall to a depth of more than 10 inches is needed in letter, e, w, s, or c, to the class numeral, for example, places to break up the tillage pan. If steeper soils are IIe. The upslope from these soils, diversions are necessary in places to intercept runoff.

up the tillage pan. If steeper soils are upslope from Grasses and legumes in the rotation help to control these soils, diversions are necessary in places to erosion and to maintain or improve tilth. intercept runoff. Grain and grass respond to nitrogen fertilizers, and Grasses and legumes in the rotation help to maintain or legumes respond to sulfur and phosphorus fertilizers. improve tilth and to control erosion. CAPABILITY UNIT IIe-2 Grain and grasses respond to nitrogen fertilizers, and This unit consists of well drained Athena and Calouse legumes respond to sulfur and phosphorus fertilizers. soils. These soils are more than 60 inches deep. Slopes CAPABILITY UNIT IIw-1 range from 3 to 7 percent. Permeability is moderate, and This unit consists of somewhat poorly drained Covello the available water capacity is high. Surface runoff is and Pedigo soils. These soils are more than 60 inches deep. slow, and the erosion hazard is slight. The annual Slopes range from 0 to 3 percent. Permeability is precipitation ranges from 15 to 18 inches. The frost-free moderate, and the available water capacity is high. season is 120 to 140 days. Surface runoff is very slow, and there is little or no Wheat, barley, peas, alfalfa, and grass are the erosion hazard. Wetness restricts root penetration and principal crops. These soils can be cropped annually delays spring tillage. The annual precipitation ranges with intermittent fallow in the rotation. Crop rotations from 15 to 20 inches. The frost-free season is 130 to generally used are wheat-fallow, wheat-barley-fallow, 155 days. annual grain, or wheat-peas-wheat-fallow. Wheat, barley, and grass and clover for hay and These soils can be farmed without excessive erosion if pasture are the principal crops. These soils can be waterways are shaped, packed, and seeded to grass; cropped annually. They are commonly farmed in grain- crop residue is mixed in the tillage layer; maximum fallow, annual grain, or legume-grass rotations. residue of straw is left on the surface at seeding time; Good management for these soils includes shaping and tillage is across the slope; and fall grain is seeded early packing waterways and seeding them to grass, mixing enough to provide winter cover. If no winter cover crop is crop residue into the tillage layer, and leaving maximum grown and no stubble is left standing, the surface is kept residue of straw on the surface at seeding time. If steeper rough and cloddy. If steeper soils are upslope from these soils are upslope from these soils, diversions are soils, diversions are necessary in places to intercept necessary in places to intercept runoff. If no winter runoff. Terraces, diversions, or stripcropping is needed to cover crop is grown and no stubble is left standing, the help control erosion on long slopes that have no grass and surface is kept rough and cloddy. In some years winter legume cover. Chiseling to a depth of more than 10 wheat is drowned out by water that ponds in inches will break up the tillage pan. depressions. Open drains or tile drains are needed in Grasses and legumes in the rotation help to control such places. Chiseling is needed in places every few erosion and to maintain or improve tilth. years to break up the tillage pan. Pans form quickly if Grain and grasses respond to nitrogen fertilizers, and the soils are cultivated when wet. legumes respond to sulfur and phosphorus fertilizers. Grasses and legumes in the rotation help to maintain CAPABILITY UNIT IIe-3 or improve tilth. This unit consists of well drained Palouse soils and Grain and grasses respond to nitrogen fertilizers, moderately well drained Thatuna soils. These soils are and legumes respond to sulfur and phosphorus fertilizers. more than 60 inches deep. Slopes range from 3 to 7 CAPABILITY UNIT IIw-2 percent. Permeability is moderate to moderately slow, and This unit consists of somewhat poorly drained the available water capacity is high. Surface runoff is Caldwell soils. These soils are more than 60 inches slow, and the erosion hazard is slight. The annual deep. Slopes range from 0 to 3 percent. Permeability is precipitation ranges from 18 to 23 inches. The frost-free moderately slow, and the available water capacity is season is 110 to 130 days. high. Surface runoff is very slow, and there is little or Wheat, barley, dry peas, lentils, grass for seed, and no erosion hazard. Root penetration and spring tillage are alfalfa and grass for hay or pasture are the principal restricted by wetness. The annual precipitation ranges crops. These soils can be cropped annually. They are from 18 to 23 inches. The frost-free season is 100 to commonly farmed in the following rotations: wheat- 135 days. fallow, wheat-peas or lentils, annual grains, grass for These soils can be cropped annually. Wheat, barley, seed, 3 years of wheat-barley-peas or lentils, and 3 oats, lentils, peas, grass for seed, and legumes and years of alfalfa and grass. grass for hay or pasture are the principal crops. They These soils can be farmed without excessive erosion if are commonly grown in the following rotations wheat- all crop residue is mixed into the tillage layer; maximum peas or lentils, wheat-barley-peas or lentils, annual residue is left on the surface at seeding time; the grain, grass for seed, and hay or pasture. surface is rough and cloddy during winter; waterways are Good management for these soils includes properly properly shaped, packed, and seeded to grass; and fall shaping and packing waterways and seeding them to grain is seeded early enough to provide winter cover. grass, mixing crop residue into the tillage layer, and Contour tillage is needed in places where the slopes are leaving maximum residue on the surface at seeding more than 5 percent. Terraces, diversions, and time. If steeper soils are upslope from these soils, stripcropping are needed to help control erosion on diversions are necessary in places to intercept runoff. long slopes that have no grass and legume cover. If no winter cover crop is grown and no stubble is Chiseling to a depth of more than 10 inches will break

imum residue of straw is left on the surface at seeding left standing, the surface is kept rough and cloddy. In time; the surface is rough and cloddy during winter; and some years winter wheat is drowned out by water that fall grain is seeded early enough to provide winter cover. ponds in depressions. Open drains or tile drains are Divided slopes, terraces, diversions, or stripcropping is needed in such areas. Chiseling is needed in places needed to help control erosion on long slopes that have every few years to break up the tillage pan. Pans form no grass or legume cover. Chiseling in fall to a depth of quickly if the soils are cultivated when wet, more than 10 inches is needed in places to break up the Grasses and legumes in rotation help to maintain or tillage pan. improve tilth. Grass and alfalfa help to control erosion and to Grain and grasses respond to nitrogen fertilizers, and maintain or improve tilth. When plowing out a crop of legumes respond to sulfur and phosphorus fertilizers. grasses or legumes, the plow furrow should be turned CAPABILITY UNIT IIe-1 uphill. This unit consists of well drained Hermiston, Onyx, and Grasses and grain respond to nitrogen fertilizers, and Mondovi soils. These soils are more than 60 inches deep. alfalfa responds to sulfur and phosphorus fertilizers. Slopes are 0 to 3 percent. Permeability is moderate, and CAPABILITY UNIT IIIe-2 the available water capacity is high. Surface runoff is This unit consists of well drained Chard, Endicott, very slow, and there is little or no erosion hazard. The and Walla Walla soils. These soils are mainly more annual precipitation ranges from 12 to 18 inches. The than 60 inches deep, but Endicott soils are underlain by frost-free season is 130 to 155 days. a lime-silica cemented hardpan at a depth of 20 to 40 These soils can be farmed in a grain-fallow or annual inches. Slopes range from 3 to 25 percent. Permeability grain rotation. Wheat and barley are the principal is moderate in Chard and Walla Walla soils. It is crops. Occasionally legumes and grasses are grown for moderate in Endicott soils to a depth of 20 to 40 hay or pasture. inches and very slow below a depth of 20 to 40 inches. The Good management for these soils includes properly available water capacity is high in Walla Walla and shaping and packing waterways and seeding them to Chard soils, and it is moderate to moderately high in the grass, mixing crop residue into the tillage layer, leaving Endicott soils. Generally, surface runoff is slow to medium maximum residue of straw on the surface at seeding and the hazard of water erosion is slight to moderate. time, and seeding fall grain early enough to provide If the ground is frozen, runoff is rapid and soil erosion winter cover. If steeper soils are upslope from these soils, is severe during rainfall or when snow melts. The annual diversions are needed in places to intercept runoff. precipitation ranges from 12 to 15 inches. The frost-free Chiseling in fall to a depth of more than 10 inches is season is 130 to 155 days. needed in places every fallow year to break up the Wheat, barley, alfalfa, and grass are the principal tillage pan. If no stubble is left standing and no winter crops. Alfalfa and grass are used for hay or pasture. cover crop is grown, the surface is kept rough and These soils can be farmed in grain-fallow, 2 years of cloddy. grain followed by 1 year of fallow, or annual grain Grasses and legumes help to maintain or improve rotations. They can be farmed without excessive erosion tilth. if waterways are properly shaped, packed, and seeded Grain and grasses respond to nitrogen fertilizers, and to grass; tillage is on the contour; fall grain is seeded legumes respond to sulfur and phosphorus fertilizers. early enough to provide winter cover; crop residue is mixed into the tillage layer; maximum residue of straw CAPABILITY UNIT IIIe-1 is left on the surface at seeding time; and the surface This unit consists of well drained Farrell and is left rough and cloddy during winter. Diversions or Ritzville soils. These soils are more than 60 inches stripcropping are needed to help to control erosion on deep. Slopes range from 0 to 30 percent. Permeability long slopes that have no grass or legume cover. If is moderate, and the available water capacity is high. steeper soils are upslope from these soils, diversions Generally, surface runoff is very slow to medium and the are necessary in places to intercept runoff. Chiseling hazard of water erosion is slight or moderate. If the in fall to a depth of more than 10 inches is needed every ground is frozen, runoff is medium to rapid and soil fallow year to break up the tillage pan. It also allows erosion is moderate to severe during rainfall or when deeper penetration of moisture during winter and reduces snow melts. The annual precipitation ranges from 11 to runoff in spring. 12 inches. The frost-free season is 140 to 155 days. Grasses and legumes in the rotation help to control Wheat, alfalfa, and grass are the principal crops. erosion and to maintain or improve tilth. When plowing These soils are farmed in grain-fallow or alfalfa and grass out a crop of grass or alfalfa, the plow furrow should rotations. Winter wheat produces higher yields than be turned uphill. spring wheat. Yields of spring grain are low, and the Grain and grasses respond to nitrogen fertilizers, and amount of straw produced is insufficient to control erosion. legumes respond to sulfur and phosphorus fertilizers. Alfalfa and grass are used for pasture. These soils can be farmed in a grain-fallow rotation CAPABILITY UNIT IIIe-3 without excessive erosion if waterways are properly This unit consists of well drained Athena, Calouse, shaped, packed, and seeded to grass; stubble mulch Reardan, and Uhlig soils. These soils are more than 60 tillage is used; tillage is on the contour or across the inches deep. Slopes range from 3 to 25 percent. slope; crop residue is mixed into the tillage layer; max- Permeability is moderate in Athena, Calouse, and

soils are upslope from these soils, diversions are necessary Uhlig soils. It is moderate in Reardan soils to a depth in places to intercept runoff. Chiseling to a depth of of about 15 inches and slow at a depth of more than 15 more than 10 inches after harvest breaks up the tillage inches. Generally, surface runoff is slow to medium and the pan. It also allows deeper penetration of moisture hazard of water erosion is slight to moderate. If the during winter and reduces runoff in spring. If no winter ground is frozen, runoff is rapid and water erosion is cover crop is grown and no stubble is left standing, the severe during rainfall or when snow melts. The annual surface is kept rough and cloddy. precipitation ranges from 15 to 19 inches. The frost-free Grasses and legumes in the rotation help to control season is 100 to 140 days. The available water capacity is erosion and to maintain or improve tilth. When plowing high. out a crop of grasses or legumes, the plow furrow These soils can be cropped annually with intermittent should be turned uphill. fallow in the rotations. Wheat, barley, peas, alfalfa, Grain and grasses respond to nitrogen fertilizers, and grass are the principal crops. They are commonly and legumes respond to sulfur and phosphorus grown in wheat-fallow, annual grain, wheat-peas- fertilizers. wheat-barley-fallow, or wheat-barley-fallow rotations. Alfalfa and grass are used for hay or pasture. CAPABILITY UNIT IIIe-5 These soils can be farmed without excessive erosion if This unit consists of well drained Naff soils and waterways are shaped, packed, and seeded to grass; moderately well drained Thatuna and Tilma soils. These tillage is on the contour; fall grain is seeded early soils are more than 60 inches deep. Slopes range from 3 enough to provide winter cover; crop residue is mixed into to 25 percent. Permeability is moderately slow in Naff the tillage layer; maximum residue of straw is left on and Thatuna soils and slow in Tilma soils. The available the surface at seeding time; and the surface is rough water capacity is moderately high to high. Generally, and cloddy during winter. Terraces, diversions, or surface runoff is slow to medium and the erosion stripcropping is needed to help control erosion on long hazard is slight to moderate. If the ground is frozen, slopes that have no grass or legume cover. If steeper runoff is rapid and erosion is severe during rainfall or soils are upslope from these soils, diversions are when snow melts rapidly. necessary in places to intercept runoff. Chiseling to a These soils can be cropped annually. Wheat, barley, depth of more than 10 inches is needed to break the peas, lentils, grass, and alfalfa are the principal crops. tillage pan. It also allows deeper penetration of They are commonly grown in wheat-peas or lentils or moisture during winter and reduces runoff in spring. annual grain rotations. Other rotations are grass for Grasses and legumes in the rotation help to control seed and 3 years of wheat-barley-peas or lentils, or 4 erosion and to maintain or improve tilth. When plowing years of wheat-peas or lentils in combination with 3 out a crop of grass and legumes, the plow furrow should years or more of alfalfa and grass. be turned uphill. These soils can be farmed without excessive erosion if Grain and grasses respond to nitrogen fertilizers, and waterways are properly shaped, packed, and seeded to legumes respond to sulfur and phosphorus fertilizers. grass; crop residue is mixed into the tillage layer; maximum residue of straw is left on the surface at CAPABILITY UNIT IIIe-4 seeding time; tillage is minimal and on the contour; This unit consists of well drained Palouse and Snow and fall grain is seeded early enough to provide winter soils and moderately well drained Thatuna soils. These cover. Terraces, diversions, divided slopes, or soils are more than 60 inches deep. Slopes range from 7 stripcropping is needed to help control erosion on long to 25 percent. Permeability is moderate in Palouse and slopes that have no grass or legume cover. If steeper Snow soils. It is moderate in Thatuna soils to a depth soils are upslope from these soils, diversions are of 39 inches and moderately slow below a depth of 39 necessary in places to intercept runoff. Chiseling to a inches. The available water capacity is high. Generally, depth of more than 10 inches after harvest breaks up surface runoff is medium and the erosion hazard is the tillage pan. It also allows deeper penetration of moderate. If the ground is frozen, runoff is rapid and moisture during winter and reduces runoff in spring. If no erosion is severe during rainfall or when snow melts. winter cover crop is grown and no stubble is left The annual precipitation ranges from 18 to 23 inches. standing, the surface is kept rough and cloddy during The frost-free season is 110 to 130 days. winter and early spring. These soils can be cropped annually. Wheat, barley, peas. Grasses and legumes in rotation help to control lentils, grass, and alfalfa are the principal crops. They are erosion and to maintain or improve tilth. When plowing commonly grown in wheat-fallow, wheatpeas or lentils, or out a crop of grasses or legumes, the plow furrow annual grain rotations. Other rotations are grass for should be turned uphill. seed or alfalfa and grass for 3 years and wheat- Grain and grasses respond to nitrogen fertilizers, and barley-peas or lentils for 3 years. legumes respond to sulfur and phosphorus fertilizers. These soils can be farmed without excessive erosion if waterways are properly shaped, packed, and seeded to CAPABILITY UNIT IIIe-6 grass; crop residue is mixed into the tillage layer; This unit consists of well drained Anders and Benge maximum residue of straw is left on the surface at soils and somewhat excessively drained Beckley soils. seeding time; tillage is minimal and on the contour; These soils are 20 to 40 inches deep over bedrock, and fall grain is seeded early enough to provide winter gravel and cobbles, or basaltic sand. Slopes range from 0 cover. Terraces, diversions, divided slopes, or strip- to 20 percent. Permeability is moderate in Anders and cropping is needed to help control erosion on long Benge soils and moderately rapid in Beckley soils. slopes that have no grass or legume cover. If steeper

The available water capacity is moderate to ing out a crop of grasses and legumes, the plow furrow moderately high in Anders and Benge soils and low to should be turned uphill. Chiseling to a depth of more moderate in Beckley soils. Generally, surface runoff is very than 10 inches after harvest breaks up the tillage pan. It slow to medium and the erosion hazard is slight to also allows deeper penetration of moisture during moderate. If the ground is frozen, runoff is rapid and winter and reduces runoff in spring. the erosion hazard is severe during rainfall or when Grain and grasses respond to nitrogen fertilizers, and snow melts. The annual precipitation ranges from 12 to legumes respond to sulfur and phosphorus fertilizers. 16 inches. The frost-free season is 135 to 150 days. CAPABILITY UNIT IIIe-8 Wheat, barley, alfalfa, and grass are the principal This unit consists of well drained Larkin and crops. These soils are generally farmed in a wheat- Shumacher soils. These soils are more than 40 inches fallow rotation. deep. Slopes range from 3 to 15 percent. Permeability is These soils can be farmed without excessive erosion if moderately slow in the Shumacher soils and moderate waterways are shaped, packed, and seeded to grass; to moderately slow in the Larkin soils. The available crop residue is mixed into the tillage layer ; tillage is water capacity is high. Generally, surface runoff is slow minimal and across the slope; fall grain is seeded early to medium and the erosion hazard is slight to moderate. enough to provide winter cover; and maximum residue of If the ground is frozen, runoff is rapid and the erosion straw is left on the surface at seeding time. Terraces, hazard is severe during rainfall or when snow melts. The diversions, and stripcropping are needed to help control annual precipitation ranges from 18 to 23 inches. The erosion on long slopes that have no grass or legume frost-free season is 100 to 130 days. cover. If steeper soils are upslope from these soils, These soils can be cropped annually. Wheat, barley, diversions are necessary in places to intercept runoff. peas, lentils, alfalfa, and grass are the principal crops. If no stubble is left standing, the surface is kept rough They are commonly grown in annual grain, wheat-peas or and cloddy during winter. lentils, and wheat-barley-peas or lentils rotations. Other Grasses and legumes in the rotation help to control rotations are wheat-peas or lentils for 4 years and erosion and to maintain or improve tilth. When plowing alfalfa and grass for 3 years, or grass for seed for 4 out a crop of grasses or legumes, the plow furrow years. should be turned uphill. Chiseling to a depth of more These soils can be farmed without excessive erosion if than 10 inches after harvest breaks up the tillage pan. It waterways are properly shaped, packed, and seeded to also allows deeper penetration of moisture during grass; crop residue is mixed into the tillage layer; winter and reduces runoff in spring. maximum residue of straw is left on the surface at Grain and grasses respond to nitrogen fertilizers, and seeding time; tillage is minimal and on the contour; and legumes respond to sulfur and phosphorus fertilizers. fall grain is seeded early enough to provide winter cover. If no winter cover crop is grown and no stubble is CAPABILITY UNIT IIIe-7 Cheney silt loam, 0 to 7 percent slopes, is the only left standing, the surface is kept rough and cloddy. soil in this unit. This soil is 20 to 40 inches deep over Terraces, diversions, or stripcropping is needed to help sand, gravel, and cobbles. It is well drained. Perme- control erosion on long slopes that have no grass or ability is moderate, and the available water capacity is legume cover. If steeper soils are upslope from these moderate or moderately high. Generally, surface runoff soils, diversions are necessary in places to intercept is very slow to slow and the erosion hazard is slight. If runoff. the ground is frozen, runoff is medium and the erosion Grasses and legumes in the rotation help to control hazard is moderate during rainfall or when snow melts. erosion and to maintain or improve tilth. Chiseling to a The annual precipitation is 15 to 18 inches. The frost-free depth of more than 10 inches is needed in places every season is 130 to 140 days. second crop to break up the tillage pan. It also allows This soil can be cropped annually. Wheat, barley, deeper penetration of moisture during the winter and alfalfa, and grass are the principal crops. They are reduces runoff in spring. commonly grown in wheat-fallow, wheat-barley-fallow, or Grain and grasses respond to nitrogen fertilizers, and annual grain rotations. legumes respond to sulfur and phosphorus fertilizers. This soil can be farmed without excessive erosion if CAPABILITY UNIT IIIw-1 waterways are properly shaped, packed, and seeded to This unit consists of somewhat poorly drained Konert grass; crop residue is mixed into the tillage layer; and Latah soils. These soils are more than 60 inches maximum residue of straw is left on the surface at deep. Slopes range from 0 to 3 percent. Permeability is seeding time; tillage is minimal and on the contour; slow in the Konert soils and very slow in the Latah and fall grain is seeded early enough to provide winter soils, and the available water capacity is high. Root cover. Terraces, diversions, and stripcropping are penetration is somewhat limited by the finer textured needed to help control erosion on long slopes that have no underlying material and by excess water. Runoff is very grass and legume cover. If steeper soils are upslope from slow, and there is little or no erosion hazard. Some this soil, diversions are necessary in places to areas are subject to flooding and deposition of alluvial intercept runoff. If no stubble is left standing, the sediment. Tillage is delayed in spring because of surface is left rough and cloddy during winter and wetness. The annual precipitation ranges from 18 to 23 spring. inches. The frost-free season is 90 to 135 days. Grasses and legumes in the rotation help to control erosion and to maintain or improve tilth. When plow-

deep. It is well drained. Permeability is moderate, and the These soils can be cropped annually. Wheat, barley, available water capacity is high. Generally, surface runoff oats, lentils, peas, grass, and legumes are the principal is rapid and the hazard of erosion is high. If the ground is crops. They are commonly grown in wheat-barley-peas or frozen, runoff is very rapid and the hazard of erosion is lentils, annual grain, or grass and legumes for hay or very severe during rainfall or when snow melts. The pasture rotations. annual precipitation ranges from 11 to 12 inches. The Good management for these soils includes shaping and frost-free season is 140 to 155 days. packing waterways and seeding them to grass, mixing Wheat, alfalfa, and grass are the principal crops. crop residue into the tillage layer, and leaving maximum This soil is commonly farmed in a wheat-fallow rotation, residue of straw on the surface at seeding time. Keeping but the hazard of erosion is high. A 6-year grain-fallow stream channels free of debris prevents overflow. If and 8-year alfalfa and grass rotation will control steeper soils are upslope from these soils, diversions are excessive erosion. Yields of spring grain are lower necessary in places to intercept runoff. Chiseling to a depth than yields of winter grain, and the amount of spring of more than 10 inches every few years breaks up the grain stubble is insufficient to control erosion. tillage pan. Moldboard, disk, or chisel plowing after This soil can be farmed without excessive erosion if harvest when the soil is dry leaves the surface rough and crop residue is mixed into the tillage layer, maximum cloddy during winter. Early fall seeding provides residue of straw is left on the surface at seeding time, the winter cover. In some years winter wheat is drowned surface is rough and cloddy during winter, tillage is on out by water that ponds in depressions. Random tile the contour or across the slope, and fall grain is seeded drains or open ditches are needed in such places. early enough to provide winter cover. Stripcropping, Grasses and legumes in the rotation help to maintain divided slope farming, runoff interception, and sediment or improve tilth. and grade stabilization structures are suitable for some Grain and grasses respond to nitrogen fertilizers, sites. and legumes respond to sulfur and phosphorus fertilizers. Alfalfa and grass help to control erosion and to CAPABILITY UNIT IIIw-2 maintain or improve tilth. Narcisse silt loam is the only soil in this unit. This Grain and grasses respond to nitrogen fertilizers, and soil is more than 60 inches deep. Slopes range from 0 to alfalfa responds to sulfur fertilizers. 3 percent. This soil is moderately well drained. Per- CAPABILITY UNIT IVe-2 meability is moderate, and the available water capacity is This unit consists of well drained Walla Walla soils. high. Surface runoff is very slow, and in places there is These soils are more than 60 inches deep. Slopes range ponding. There is little or no erosion hazard. Some from 15 to 40 percent. Permeability is moderate, and the areas are subject to flooding and deposition of alluvial available water capacity is high. Generally, surface sediment. Tillage is delayed in spring because of wetness. runoff is medium to rapid and the hazard of erosion is The annual precipitation ranges from 16 to 23 inches. moderate to high. If the ground is frozen, runoff is very The frost-free season is 100 to 135 days. rapid and the hazard of erosion is very severe during This soil can be cropped annually. Wheat, barley, oats, rainfall or when snow melts. The annual precipitation grass, and legumes are the principal crops. They are ranges from 12 to 15 inches. The frost-free season is commonly grown in rotations of annual grain and grass 130 to 155 days. and legumes for hay or pasture. Wheat, barley, alfalfa, and grass are the principal Good management for this soil includes properly shaping crops. These soils are commonly farmed in a grain- and packing waterways and seeding them to grass, fallow rotation with grass and alfalfa. mixing crop residue into the tillage layer, and leaving These soils can be farmed in a rotation of 5 to 8 maximum residue of straw on the surface at seeding years of grass or alfalfa-grass and 8 years of wheat- time. Keeping stream channels free of debris prevents fallow (one to three crops of wheat between fallow). This overflow. In places where steeper soils are upslope from can be done if crop residue is mixed into the soil, maximum this soil, diversions are necessary to intercept runoff. residue of straw is left on the surface at seeding time, Chiseling to a depth of more than 10 inches every few the surface is rough and cloddy during winter, fall grain years breaks up the tillage pan. Moldboard, disk, or chisel is seeded early enough to provide winter cover, and plowing after harvest when the soil is dry leaves the tillage and seeding are on the contour or across the surface rough and cloddy during winter. Early fall slope. If less steep soils are above these soils, chiseling seeding provides winter cover. In some years winter those soils to a depth of more than 10 inches reduces runoff wheat is drowned out by water that ponds in depressions. and the use of level terraces or diversions intercepts runoff Random tile drains or open ditches are needed in such before it reaches these soils. places. Using stripcropping, divided slopes, and runoff Grasses or legumes in the rotation help to maintain or interception and water-disposal structures is suitable for improve tilth. some sites. Controlling growth of weeds by chemicals Grain and grasses respond to nitrogen fertilizers, and reduces the need for tillage during the fallow year. legumes respond to sulfur and phosphorus fertilizers. Snow drifting is common on these soils. It smothers CAPABILITY UNIT IVe-1 fall-seeded grain, permits weed invasion, and causes Ritzville silt loam, 30 to 40 percent slopes, is the excessive rill erosion when the snow melts in spring. only soil in this unit. This soil is more than 60 inches Snow drifting can be reduced by leaving stubble on hilltops and on the upper part of adjacent south- and west-facing side slopes and by planting a windbreak

These soils can be farmed in annual grain or a rota- of trees and shrubs to intercept the snow before it tion of several years of alfalfa and grass and several reaches these soils. years of annual grain. This can be done without excessive Alfalfa and grass help to control erosion and to erosion if crop residue is mixed into the tillage layer, improve tilth. maximum residue is left on the surface at seeding time, the Grain and grasses respond to nitrogen fertilizers, and surface is rough or cloddy during the winter, tillage is alfalfa responds to sulfur fertilizers. minimal and on the contour or across slope, and fall CAPABILITY UNIT IVe-3 grain is seeded early enough to provide winter cover. This unit consists of well drained Athena and Calouse Chiseling to a depth of more than 10 inches is needed in soils. These soils are more than 60 inches deep. Slopes places to break up the tillage pan. Chisel shank spacing range from 5 to 40 percent. Permeability is moderate, of more than 18 inches is suitable. Chiseling allows and the available water capacity is high. Surface runoff deeper penetration of moisture during winter and reduces is medium to rapid, and the erosion hazard is moderate to runoff in spring. Stripcropping and divided slopes are high. The annual precipitation ranges from 15 to 18 suitable for some sites. Hilltop or ridgetop planting of inches. The frost-free season is 120 to 140 days. windbreaks or seedlings of grass and legumes protects These soils can be cropped annually. Wheat, barley, slopes from snow drifting and from runoff. alfalfa, and grass are the principal crops. Grasses and legumes in the rotation help to control These soils can be farmed in annual grain or a erosion and to maintain or improve tilth. rotation of several years of alfalfa and grass and several Grain and grasses respond to nitrogen fertilizers, and years of annual grain. This can be done without legumes respond to sulfur and phosphorus fertilizers. excessive erosion if crop residue is mixed into the CAPABILITY UNIT IVe-5 tillage layer, maximum residue of straw is left on the This unit consists of well drained Naff soils and surface at seeding time, the surface is rough and cloddy moderately well drained Thatuna and Tilma soils. These during winter, tillage and seeding are across the slope or soils are more than 60 inches deep. Slopes range from 25 on the contour, and fall grain is seeded early enough to to 40 percent. Permeability is moderately slow or slow, provide winter cover. Using stripcropping, divided slopes, and the available water capacity is moderately high or and runoff interception and water disposal structures is high. Generally, surface runoff is rapid and the erosion suitable for some sites. If less steep soils are above these hazard is high. If the ground is frozen, runoff is very soils, chiseling to a depth of more than 10 inches reduces rapid and the hazard of erosion is very severe during runoff and intercepts it before it reaches these soils. rainfall or when snow melts. The annual precipitation Although erosion cannot be controlled in a grain- ranges from 18 to 23 inches. The frost-free season is 110 fallow rotation, it can be greatly reduced by annual to 130 days. rotations and by use of stripcropping or divided slopes These soils can be cropped annually. Wheat, barley, with alternate strips of grain and fallow. Controlling peas, lentils, grass, and alfalfa are the principal crops. growth of weeds by chemicals reduces the need for These soils can be farmed in annual grain or rotations tillage during the fallow years. of several years of annual grain and several years of Snow drifting is common on these soils. It smothers alfalfa and grass, or 3 or 6 years of wheat-barley-peas fall-seeded grain, permits weed invasion, and causes or lentils followed by 5 years or more of grass, or alfalfa excessive rill erosion or deep soil slips when the snow and grass. This can be done without excessive erosion if melts in spring. Snow drifting can be reduced by crop residue is mixed into the tillage layer, maximum leaving stubble on hilltops and on the upper part of residue of straw is left on the surface at seeding time, the adjacent south- and west-facing side slopes and by surface is rough and cloddy during winter, tillage is planting a windbreak of trees to intercept the snow minimal and on the contour or across slope, and fall before it reaches these steep soils. grain is seeded early enough to provide winter cover. Using alfalfa and grass in the rotation at least half the Chiseling to a depth of more than 10 inches is needed in time helps to control erosion and to improve tilth. places to break up the tillage pan. Chisel spacing of more Grain and grasses respond to nitrogen fertilizers, and than 18 inches is suitable. Chiseling allows deeper alfalfa responds to sulfur fertilizers. penetration of moisture during winter and reduces CAPABILITY UNIT IVe-4 runoff in spring. Use of stripcropping, divided slopes, This unit consists of well drained Palouse soils and and runoff interception and water disposal structures is moderately well drained Thatuna soils. These soils are suitable for some sites. Hilltop or ridgetop plantings of more than 60 inches deep. Slopes range from 25 to 40 trees or seedings of grasses and legumes protect slopes percent. Permeability is moderate in the Palouse soils. from snow drifting and from runoff. It is moderate in the Thatuna soils to a depth of 39 Grasses and legumes in the rotation help to control inches and moderately slow below a depth of 39 erosion and to maintain or improve tilth. inches. The available water capacity is high. Generally, Grain and grasses respond to nitrogen fertilizers, and surface runoff is rapid and the erosion hazard is high. If the legumes respond to sulfur and phosphorus fertilizers. ground is frozen, runoff is very rapid and erosion is very CAPABILITY UNIT IVe-6 severe during rainfall or when snow melts. The annual Only Beckley sandy loam, 20 to 40 percent slopes, is in precipitation ranges from 18 to 23 inches. The frost-free this unit. This soil is 20 to 40 inches deep to coarse season is 110 to 130 days. These soils can be cropped annually. Wheat, barley, peas, lentils, grass, and alfalfa are the principal crops.

60 inches deep. Slopes range from 3 to 25 percent. basaltic sand. It is somewhat excessively drained. Permeability is moderate or moderately slow, and the Permeability is moderately rapid, and the available water available water capacity is moderate or high. Generally, capacity is low or moderate. Generally, surface runoff is surface runoff is slow to medium and the erosion rapid and the erosion hazard is high. If the ground is hazard is slight to moderate. If the ground is frozen, frozen, runoff is very rapid and the erosion hazard is very runoff is rapid and the erosion hazard is severe during severe during rainfall or when snow melts. The annual rainfall or when snow melts. The annual precipitation precipitation ranges from 12 to 15 inches. The frost-free ranges from 18 to 23 inches. The frost-free season is season is 135 to 150 days. 100 to 130 days. '"'heat, barley, alfalfa, and grass are the principal These soils can be cropped annually. Wheat, barley, crops. This soil is commonly cropped in a wheat-fallow peas, lentils, alfalfa, and grass are the principal crops. rotation. They are commonly grown in a wheat-peas or lentil This soil can be farmed in a rotation of barley- rotation. fallow-wheat for 3 years followed by alfalfa and grass for A suitable rotation is 3 years or more of grass and 4 years. This can be done without excessive erosion if legumes and 4 years of wheat-peas or lentils or 4 years of crop residue is mixed into the tillage layer, maximum annual grains. Other suitable rotations are wheatpeas or residue of straw is left on the surface at seeding time, lentils, wheat-barley-peas or lentils, annual grain, or the surface is left rough and cloddy during winter, grass for seed. These soils can be farmed under these tillage is minimal and on the contour or across slope, rotations without excessive erosion if crop residue is and fall grain is seeded early enough to provide winter mixed into the tillage layer; maximum residue of straw cover. is left on the surface at seeding time; the surface layer is Grasses and legumes in the rotation help to control rough and cloddy during winter; a winter cover crop is erosion and to maintain or improve tilth. grown or stubble is left standing; waterways are properly Grain and grasses respond to nitrogen fertilizers, shaped, packed, and seeded to grass ; tillage and seeding and legumes respond to sulfur fertilizers. are across the slope or on the contour; and fall grain is CAPABILITY UNIT IVe-7 seeded early enough to provide winter cover. Chiseling This unit consists of a somewhat excessively drained to a depth of more than 10 inches in fall breaks up Magallon soil and well drained Roloff and Stratford the tillage pan. It also allows deeper penetration of soils. These soils are 20 to 40 inches deep over bedrock, moisture during winter and reduces runoff in spring. basaltic sand, or sand and gravel. Slopes range from 0 to Use of stripcropping, divided slopes, or diversions is 20 percent. Permeability is moderate, and the available needed to help control erosion on long slopes that have water capacity is moderate or moderately high. no grass or legume cover. If steeper soils are upslope Generally, surface runoff is very slow to medium and the from these soils, diversions are necessary to intercept erosion hazard is slight or moderate. If the ground is runoff. frozen, runoff is rapid and the erosion hazard is severe Snow drifting is common on these soils. It smothers during rainfall or when snow melts. The annual fall-seeded grain, permits weed invasion, and causes precipitation ranges from 11 to 12 inches. The frost- excessive rill erosion when the snow melts in spring. free season is 135 to 160 days. Snow drifting can be reduced by leaving stubble on Wheat is the principal crop. These soils are commonly hilltops and on the upper part of the adjacent south- farmed in a wheat-fallow rotation. and west-facing slopes and by planting a windbreak of These soils can be farmed without excessive erosion if trees to intercept the snow before it reaches these soils. waterways are properly shaped, packed, and seeded to grass; crop residue is mixed into the tillage layer; CAPABILITY UNIT IVe-9 maximum residue of straw is left on the surface at Only Walvan silt loam, 7 to 25 percent slopes, is in seeding time; the surface is rough and cloddy during this unit. This soil is more than 60 inches deep. It is winter; tillage is minimal and on the contour or across well drained. Permeability is moderate, and the available the slope; and fall grain is seeded early enough to water capacity is high. Generally, surface runoff is provide winter cover. Use of divided slopes, strip- medium and the hazard of erosion is moderate. If the cropping, or terraces is needed to help control erosion ground is frozen, runoff is rapid and the erosion on long slopes that have no grass or legume cover. If hazard is severe during rainfall or when snow melts. steeper soils are upslope from these soils, diversions are The hazard of soil blowing is severe. The annual necessary in places to intercept the runoff. Chiseling to a precipitation ranges from 12 to 15 inches. The frost- depth of more than 10 inches is needed in places free season is 130 to 150 days. every crop year to break up the tillage pan. It also allow Wheat, alfalfa, and grass are the principal crops. deeper penetration of moisture during winter and reduces This soil is commonly cropped in a wheat-fallow rotation. runoff in spring. This soil can be farmed in a crop rotation of 4 years Grasses and legumes in the rotation help to control of wheat-fallow followed by 9 years of alfalfa, grass, or erosion and to maintain tilth. When a crop of grass or both. This can be done without excessive erosion if crop legumes is plowed out, the plow furrow should be residue is mixed into the tillage layer, maximum residue turned uphill. of straw is left on the surface at seeding time, the Grain and grasses respond to nitrogen fertilizers, and surface is rough and cloddy during winter, tillage is legumes respond to sulfur fertilizers. minimal and on the contour or across the slope, and fall grain is seeded early enough to provide winter cover. CAPABILITY UNIT IVe-8 Divided slopes, stripcropping, or terraces are needed This unit consists of well drained Larkin, Schum- acher, and Tekoa soils. These soils are 20 to more than to help to control erosion on long slopes that have no from 14 to 18 inches. The frost-free season is 130 to grass or legume cover. If steeper soils are upslope from 145 days. this soil, diversions are necessary in places to intercept Wheat, barley, alfalfa, and grass are the principal runoff. Chiseling to a depth of more than 10 inches is crops. This soil is commonly cropped in a wheat- needed in places every crop year to break up the tillage fallow rotation. pan. It also allows deeper penetration of moisture during This soil can be farmed in a rotation of wheat- winter and reduces runoff in spring. barley-fallow for 3 years, and alfalfa-grass for 3 years. Grasses and legumes in the rotation help to control This can be done without excessive erosion if water- erosion and to maintain or improve tilth. When a crop of ways are shaped, packed, and seeded to grass ; all crop grasses and legumes is plowed out, the plow furrow residue is mixed into the tillage layer; maximum residue should be turned uphill. of straw is left on the surface at seeding time; the Grain and grasses respond to nitrogen fertilizers, and surface is rough and cloddy during winter; tillage is alfalfa responds to sulfur fertilizers. minimal and on the contour or across the slope; and fall grain is seeded early enough to provide winter cover. CAPABILITY UNIT IVe-10 Use of divided slopes, stripcropping, or terraces is needed This unit consists of well drained Garfield, Naff, Palouse, to help control erosion on long slopes that have no and Staley soils. The Naff soil is in complex with the grass or legume cover. Chiseling to a depth of more than Garfield soils. These soils are more than 60 inches 10 inches is needed to break up the tillage pan. It also deep. Slopes range from 3 to 25 percent. Permeability is allows deeper penetration of moisture in spring. slow to moderate, and the available water capacity is Grasses and legumes in the rotation help to control high. Generally, surface runoff is slow to medium and erosion and to maintain or improve tilth. When a crop the erosion hazard is slight to moderate. If the ground of grass and alfalfa is plowed out, the plow furrow is frozen, runoff is very rapid and the erosion hazard is should be turned uphill. severe during rainfall or when snow melts. The annual Grain and grasses respond to nitrogen fertilizers, and precipitation ranges from 18 to 23 inches. The frost-free legumes respond to sulfur fertilizers. season is 110 to 140 days. These soils can be cropped annually. Wheat, barley, CAPABILITY UNIT IVe-12 peas, lentils, grass, and alfalfa are the principal crops. Only Tucannon silt loam, 7 to 25 percent slopes, is in They are commonly grown in a wheat-peas or lentils this unit. This soil is 20 to 40 inches deep to basalt rotation or a wheat-fallow rotation. bedrock. It is well drained. Permeability is moderate, and These soils can be farmed in a rotation of annual the available water capacity is moderate to moderately grain or of annual grain for 4 years followed by alfalfa, high. Generally, surface runoff is medium and the erosion grass, or both for 4 years. This can be done without hazard is moderate. If the ground is frozen, runoff is excessive erosion if waterways are properly shaped, rapid and the erosion hazard is severe during rainfall or packed, and seeded to grass ; all crop residue is mixed into when snow melts. The annual precipitation ranges from the tillage layer; maximum residue of straw is left on 16 to 23 inches. The frost-free season is 110 to 130 the surface at seeding time; the surface is rough and days. cloddy during winter; tillage is minimal and on the This soil can be cropped annually. Wheat, barley, contour or across the slope; and fall grain is seeded early peas, lentils, grass, and alfalfa are the principal crops. enough to provide winter cover. Chiseling to a depth of This soil can be farmed in a 3-year wheat-barley- more than 10 inches is needed in places to break up the peas or lentils rotation followed by a 6-year rotation of tillage pan. Chisel spacing of more than 18 inches is alfalfa, grass, or both. This can be done without suitable. Chiseling allows deeper penetration of moisture excessive erosion if waterways are properly shaped, during winter and reduces runoff in spring. Divided slopes packed, and seeded to grass; crop residue is mixed into are needed to help control erosion on long slopes that the tillage layer; maximum residue of straw is left on have no grass or legume cover. Hilltop or ridgetop the surface at seeding time; the surface is rough and seedings of grass and legumes protect slopes from snow cloddy during winter; tillage is minimal and on the drifting and from runoff. contour or across slope; and fall grain is seeded early Grasses and legumes in the rotation help to control enough to provide winter cover. Use of divided slopes and erosion and to maintain or improve tilth. When a crop stripcropping is needed to help control erosion on long of grasses and legumes is plowed out, the plow furrow slopes that have no grass or legume cover. If steep should be turned uphill. soils are upslope from this soil, diversions are Grain and grasses respond to nitrogen fertilizers, and necessary in places to intercept runoff. Chiseling to a legumes respond to sulfur and phosphorus fertilizers. depth of 10 inches or more is necessary in places to break up the tillage pan. It also allows deeper CAPABILITY UNIT IVe-11 penetration of moisture during winter and reduces Only Spofford silt loam, 0 to 15 percent slopes, is in runoff in spring. this unit. This soil is 60 inches deep. It is moderately Grasses and legumes in the rotation help to control well drained. Permeability is slow, and the available water erosion and to maintain or improve tilth. When a crop of capacity is moderately high. Generally, surface runoff is grass or legumes is plowed out, the plow furrow very slow to medium and the erosion hazard is slight to should be turned uphill. moderate. If the ground is frozen, runoff is rapid and the Grain and grasses respond to nitrogen fertilizers, and erosion hazard is severe during rainfall or when snow legumes respond to sulfur and phosphorus fertilizers. melts. The annual precipitation ranges

CAPABILITY UNIT IVe-13 Grasses or legumes in the rotation help to control Only Asotin silt loam, 7 to 25 percent slopes, is in erosion and to maintain or improve tilth. When a crop of this unit. This soil is 20 to 40 inches deep to basalt. grass or legumes is plowed out, the plow furrow It is well drained. Permeability is moderate, and the should be turned uphill. available water capacity is moderately high. Generally, Grain and grasses respond to nitrogen fertilizers, and surface runoff is medium and the erosion hazard is legumes respond to sulfur and phosphorus fertilizers. moderate. If the ground is frozen, runoff is rapid and the erosion hazard is severe during rainfall or when snow CAPABILITY UNIT IVw-1 melts. The annual precipitation ranges from 12 to 15 Only Konert silty clay loam is in this unit. This soil is inches. The frost-free season is 135 to 160 days. more than 60 inches deep. Slopes range from 0 to 3 Wheat, barley, alfalfa, and grass are the principal percent. This soil is somewhat poorly drained. crops. Permeability is slow, and the available water capacity is This soil can be farmed in a wheat-barley-fallow or high. Surface runoff is very slow, and there is little or hay and pasture rotation without excessive erosion if no erosion hazard. In many places runoff is ponded. waterways are properly shaped, packed, and seeded to Some areas are subject to overflow and deposition. Tillage grass; crop residue is mixed into the tillage layer; is delayed in spring because of wetness. The annual maximum residue of straw is left on the surface at precipitation ranges from 20 to 23 inches. The frost-free seeding time; the surface is rough and cloddy during season is 90 to 110 days. winter; tillage is minimal and on the contour or across This soil can be cropped annually. Wheat, barley, the slope; and fall grain is seeded early enough to grass, and legumes are the principal crops. They are provide winter cover. Use of stripcropping, divided commonly grown in a rotation of annual grain or hay or slopes, and runoff interception and water disposal pasture. Grass is grown for seed. structures is suitable for some sites. Chiseling to a Good management for this soil includes shaping and depth of more than 10 inches is needed in places every packing waterways and seeding them to grass, mixing other year to break up the tillage pan. It also allows crop residue into the tillage layer, leaving maximum deeper penetration of moisture during winter and residue of straw on the surface at seeding time, and reduces runoff in spring. keeping the surface rough and cloddy during winter. Grasses and legumes in the rotation help to control Keeping stream channels free of debris helps to prevent erosion and to maintain or improve tilth. When a crop of overflow. If steeper soils are upslope from this soil, grass or legumes is plowed out, the plow furrow diversions are necessary in places to intercept the runoff. should be turned uphill. Chiseling to a depth of more than 10 inches every few Grain and grasses respond to nitrogen fertilizers, years breaks up the tillage pan. Moldboard, disk, or chisel and legumes respond to sulfur and phosphorus fertilizers. plowing after harvest when the soil is dry leaves the surface rough and cloddy through winter. Early fall CAPABILITY UNIT IVe-14 seeding provides winter cover. In some years wheat is Only Almota silt loam, 7 to 25 percent slopes, is in drowned out by water that ponds in depressions. this unit. This soil is 20 to 40 inches deep to basalt Random tile drains or open ditches are needed in such bedrock. It is well drained. Permeability is moderate, and places. the available water capacity is moderate or moderately Grasses and legumes in the rotation help to maintain or high. Generally, surface runoff is medium and the erosion improve tilth. hazard is moderate. If the ground is frozen, runoff is Grain and grasses respond to nitrogen fertilizers, rapid and the erosion hazard is severe during rainfall or and legumes respond to sulfur and phosphorus when snow melts. The annual precipitation ranges fertilizers. from 15 to 18 inches. The frost-free season is 130 to 140 days. CAPABILITY UNIT IVw-2 Wheat, barley, alfalfa, and grass are the principal Only Emdent silt loam, drained, is in this unit. This soil crops. This soil is commonly cropped in a wheat-fallow is 60 inches deep. Slopes range from 0 to 3 percent. This rotation. soil is alkaline, and it is somewhat poorly drained. This soil can be farmed in a crop rotation of wheat- Permeability is moderate, and the available water ca- barley-fallow, annual grain, or 2 years of annual grain pacity is high. Surface runoff is very slow, and there is followed by 6 years of alfalfa, grass, or both. This can little or no erosion hazard. In many places runoff water be done without excessive erosion if waterways are is ponded. Tillage is delayed in spring because of shaped, packed, and seeded to grass; crop residue is wetness. The annual precipitation ranges from 11 to 16 mixed into the tillage layer; maximum residue of straw inches. The frost-free season is 135 to 145 days. is left on the surface at seeding time; the surface is Wheat, barley, oats, grass, and legumes are the rough and cloddy during winter ; tillage is minimal and principal crops. This soil can be cropped annually. on the contour or across the slope; and fall grain is Good management includes mixing all crop residue into seeded early enough to provide winter cover. Use of the tillage layer, leaving maximum residue of straw on stripcropping, divided slopes, and runoff interception and the surface at seeding time, and keeping the surface water disposal structures is suitable for some sites. rough and cloddy during winter. Chiseling to a depth of Chiseling to a depth of more than 10 inches is necessary in more than 10 inches breaks up the tillage pan. places every other year to break up the tillage pan. It 11loldboard, disk, or chisel plowing after harvest when the also allows deeper penetration of moisture during soil is dry leaves the surface rough and cloddy during winter and reduces runoff in spring. winter. Early fall seeding provides winter cover.

In some years winter wheat is drowned out by water CAPABILITY UNIT VIs-1 that ponds in depressions. Random tile drains or open This unit consists of well drained Bakeoven, Cheney, ditches are needed in areas that have proper outlets. Speigle, Tucannon, and Hesseltine soils. The Bakeoven Grasses and legumes in the rotation help to and Tucannon soils in this capability unit are mapped in maintain or improve tilth. complex. The Cheney, Tucannon, and Hesseltine soils are Grain and grasses respond to nitrogen fertilizers, and 20 to 40 inches deep to bedrock or gravel. The Speigle legumes respond to sulfur and phosphorus fertilizers. soils are 40 to 60 inches or more deep, and the Bakeoven soils are 6 to 10 inches deep to bedrock. Slopes range from 0 to 30 percent. Permeability is CAPABILITY UNIT VIe-1 moderate and moderately slow, and the available water This unit consists of well drained Almota, Asotin, capacity is low to high. Surface runoff is very slow to Athena, Palouse, Roloff, Schumacher, Starbuck, Tekoa, medium, and there is a moderate water erosion hazard or and Walla Walla soils; somewhat excessively drained none. The annual precipitation ranges from 15 to 23 Magallon soils; and moderately well drained Thatuna inches. The frost-free season is 110 to 155 days. soils. The Almota, Asotin, Magallon, Roloff, and Tekoa These soils are suitable for grazing. The Hesseltine soils are 20 to 40 inches deep to bedrock, gravel, or and Speigle soils are used for woodland and limited sand. The Athena, Palouse, Schumacher, Thatuna, and grazing. A permanent cover helps to control erosion. Walla Walla soils are 40 to more than 60 inches deep Cultivation should be limited to the establishment of to bedrock. The Starbuck soils are about 15 inches grasses in areas that need seeding. deep to bedrock. Slopes range from 0 to 65 percent. The annual precipitation ranges from 11 to 23 inches. CAPABILITY UNIT VIw-1 The frost-free season is 100 to 160 days. Permeability This unit consists of somewhat poorly drained Emdent ranges from moderately rapid to moderately slow, and and Pedigo soils. The Emdent soils are more than 60 the available water capacity ranges from low to high. inches deep, and the Pedigo soils are 40 to 60 inches Surface runoff is very slow to very rapid, and the deep to a cemented hardpan. Slopes range from 0 to 3 erosion hazard is slight to very high. percent. Permeability is moderate to very slow, and the These soils are suitable for grazing. A permanent available water capacity is moderately high and high. grass cover helps to control erosion. Limiting These soils have a water table at a depth of 24 to 30 cultivation to the establishment of grasses and inches. Surface runoff is very slow, and there is little or no legumes is needed on soils that have slopes of less than erosion hazard. The annual precipitation ranges from 11 40 percent. to 18 inches. The frost-free season is 130 to 155 days. Most areas of these soils are used for grazing. Areas CAPABILITY UNIT VIe-2 that need reseeding can be cultivated and seeded to This unit consists of well drained Athena, Calouse, alkaline-tolerant grasses. Lance, Palouse, Risbeck, and Walla Walla soils. These CAPABILITY INIT VIIe-1 soils are more than 60 inches deep. The Calouse soils This unit consists of well drained Alpowa, Linville, have lime at a depth of 20 to 40 inches, and the Lance Ritzville, and Starbuck soils. The Alpowa and Linville soils and Risbeck soils have lime and lime-silica cemented are 40 to more than 60 inches deep to bedrock, the lenses throughout the profile. Slopes are mostly 20 to Ritzville soils are more than 60 inches deep to 40 percent but range from 5 to 40 percent. bedrock, and the Starbuck soils are 10 to 20 inches Permeability is moderate to moderately slow, and the deep to bedrock. Slopes range from 30 to 65 percent. available water capacity is moderately high and high. Permeability is moderate, and the available water The annual precipitation ranges from 12 to 23 inches. capacity is low to high. Surface runoff is rapid to very The frost-free season is 110 to 155 days. Surface rapid, and the erosion hazard is high to very high. runoff is medium to very rapid, and the erosion hazard is The annual precipitation ranges from 11 to 20 inches. moderate to very high. The frost-free season is 110 to 160 days. These soils are suitable for hay or pasture and for These soils are suitable for grazing. In areas where grazing. Most of these soils are eroded, have low slopes are less than 40 percent and where the range is production potential, and need permanent cover. Cultiva- in poor condition, range seeding is practical. tion should be limited to the establishment of perma- nent cover. CAPABILITY UNIT VIIe-1 This unit consists of well drained Alpowa, Anders, CAPABILITY UNIT VIe-3 Asotin, Bakeoven, Benge, Gwin, Kuhl, Linville, Speigle, This unit consists of well drained Larkin and Tekoa Stratford, and Tucannon soils. The Anders, Asotin, soils. The Larkin soils are 40 to 60 inches or more Benge, Stratford, and Tucannon soils are 20 to 40 deep to bedrock. Slopes range from 25 to 55 percent. inches deep to bedrock or gravel. The Bakeoven soils are Permeability is moderate to moderately slow, and the 6 to 10 inches deep to bedrock, and the Gwin and Kuhl available water capacity is moderately high to high. soils are 10 to 20 inches deep to bedrock. The Alpowa, The annual precipitation ranges from 20 to 23 inches. Linville, and Speigle soils are 40 to 60 inches deep or The frost-free season is 100 to 135 days. Surface more to bedrock. Permeability is moderate or runoff is rapid to very rapid, and the erosion hazard is moderately slow, and the available water capacity is high to very high. low to high. Slopes are 0 to 65 percent. Surface runoff These soils are used for woodland and limited is very slow to very rapid, and the erosion hazard grazing. is slight to very high. The annual precipitation ranges varieties; appropriate tillage practices, including time of from 11 to 23 inches. The frost-free season is 110 to tillage and seedbed preparation and tilling when soil 160 days. moisture is favorable; control of weeds, plant diseases, These soils are suitable for grazing. The Speigle and harmful insects; favorable soil reaction and optimum soils are also used for woodland. In some areas where levels of nitrogen, phosphorus, and trace elements for each slopes are less than 40 percent and where the range is crop; effective use of crop residue, barnyard manure, and in poor condition, range seeding is practical. green manure crops; harvesting crops with the smallest possible loss; and timeliness of all fieldwork. CAPABILITY UNIT VIIIs-1 This unit consists of Rock outcrop and Rock Range outcrop-Lithic Xerorthents complex. These miscellaneous areas are on side slopes along major drainageways and Approximately 227,900 acres, or about 16 percent, of in channeled scablands. Rock outcrop is essentially Whitman County is range. Soils used for range are barren land, or it supports a sparse stand of vegetation in generally those that are unsuited to crops and too dry rock fractures. Lithic Xerorthents are 5 to 12 inches to support trees. Many of the farms include areas of deep over bedrock and are mapped in complex with soils that are better suited to range than to other uses. Rock outcrop. They provide limited grazing in early Soils that have the capacity to produce the same spring. kinds, amounts, and proportions of range plants are Rock outcrop and Lithic Xerorthents are used for grouped into range sites. A range site is the product of wildlife habitat, recreational areas, limited grazing, and all environmental factors responsible for its development. esthetic purposes. A plant community existing within a range site that has not undergone abnormal disturbance is the potential, CAPABILITY UNIT VIIIw-1 or climax, plant community for that site. Climax plant This unit consists of Riverwash and Xerofluvents. communities are not precise or fixed in their These miscellaneous areas are along the Snake and composition but vary, within reasonable limits, from Palouse Rivers and their drainageways. Riverwash year to year and from place to place. consists of areas of coarse sand, gravel, and Abnormal disturbance such as overuse by livestock, cobblestones that are generally less than 3 feet above excessive burning, erosion, or plowing results in the normal level of streams. Xerofluvents consists of areas changes in the climax plant community or even of soils that formed in cobbly alluvium on bottom land, complete destruction if the disturbance is drastic enough. terraces, and alluvial fans that are generally 4 to When the range site has not deteriorated significantly more than 6 feet above the normal level of streams. Areas under such disturbance, secondary plant succession of Riverwash are subject to change in size and shape progresses in the direction of the natural potential or even during normal stream flow. Xerofluvents are subject climax plant community for the site. to flooding. Four range condition classes are used to indicate the Riverwash and Xerofluvents are used for wildlife degree of departure from the potential, or climax, habitat and for recreational and esthetic purposes. vegetation brought about by grazing or other uses. The classes show the present condition of the native Estimated yields vegetation on a range site in relation to the native The per acre average yields that can be expected of vegetation that could grow there. the principal crops under a high level of management A range is in excellent condition if 76 to .100 percent of are shown in table 2. In any given year, yields may be the vegetation is the same kind as that in the climax. higher or lower than those indicated in table 2, because of It is in good condition if the percentage is 51 to 75; seasonal variations in rainfall and other climatic factors. fair, if the percentage is 26 to 50; and poor, if the Absence of a yield estimate indicates that the crop is not percentage is 25 or less. suited to or not commonly grown on the soil or that When changes occur in the climax plant community irrigation of a given crop is not commonly practiced on due to livestock use or disturbance, some plant species the soil. will increase and others will decrease. Species increasing The predicted yields are based mainly on the or decreasing depends upon the grazing animal, season experience and records of farmers, conservationists, and of use, and the degree of utilization. By comparing the Extension agents. Results of field trials and composition of the present plant community to the demonstrations and available yield data from nearby potential plant community, it is possible to see how counties were also considered. individual species have increased while others have The latest crop management and soil practices used by decreased. Plants that are absent in the climax many farmers in the county are assumed in predicting community but which show up in the present plant the yields. Hay and pasture yields are predicted for community are invaders for the site. varieties of grasses and legumes suited to the soil. A The composition of climax and present plant few farmers may be using more advanced practices and communities, with other range site information, are obtaining average yields higher than those shown in provides the basis for selecting range management. table 2. Management on rangeland generally tries to increase The management needed to achieve the indicated desirable plants and restore rangeland to as near yields of the various crops depends on the kind of soil and the crop. Such management provides drainage, DEWAYNE J. BECK, range conservationist, Soil Conservation Service, erosion control, and protection from flooding; proper assisted in the preparation of this section. planting and seeding rates ; suitable high-yielding crop climax conditions as possible. Some programs are the giant wildrye has been destroyed. A good summer designed to create or maintain plant communities some- fallow seedbed is essential. A drill with deep furrow what removed from the climax to fit specific needs in the openers is suitable for seedling establishment. Salts are grazing program, to provide wildlife habitat, or for less concentrated in the furrow bottoms. other benefits. Any management objective should be LOAMY RANGE SITE (L-2) compatible with conservation objectives. This range site consists of well drained and Total production refers to the amount of vegetation somewhat excessively drained, moderately permeable that can be expected from a well managed range that and moderately slowly permeable silt loams, cobbly silt is supporting the potential plant community. It is loams, very cobbly silt loams, loams, very cobbly loams, expressed in pounds per acre of air-dry vegetation very fine sandy loams, and sandy loams. It covers about for favorable and unfavorable years. A favorable year is 77,200 acres of upland terraces, outwash plains, canyon one in which the amount and distribution of sides, and foot slopes. The available water capacity is precipitation and the temperatures result in growing moderate to high. Some soils have a hardpan at a depth conditions substantially better than average; an of 20 to 40 inches. Slopes are mostly 7 to 25 percent unfavorable year is one in which growing conditions but range from 0 to 40 percent, Elevation ranges from are well below average, generally because of low 500 to 2,500 feet. available soil moisture. The annual precipitation is 11 to 15 inches. About 80 Dry weight refers to the total air-dry vegetation percent of this moisture is received between October 1 and produced per acre each year by the potential plant June 1. The summers are hot and dry. The period community. All vegetation, that which is highly between April 1 and June 15 is favorable for plant palatable to livestock and that which is unpalatable, is growth. included. Some of the vegetation also may be grazed The potential plant community is characterized by extensively by wildlife, and some of it may not. grasses. Bluebunch wheatgrass makes up 50 percent of The range site for soils can be determined by the vegetation, by weight, and Idaho fescue makes up 20 referring to the last paragraph of the appropriate percent. The rest of the plant community is Sandberg mapping unit in the section "Descriptions of the Soils." bluegrass, prairie junegrass, threadleaf sedge, giant The range sites of Whitman County are described in the wildrye, Thurber needlegrass, big bluegrass, wild following pages. buckwheat, gromwell, arrowleaf balsamroot, fleabane, lupine, milkvetch, yarrow, hawksbeard, phlox, rabbitbrush, ALKALI RANGE SITE annual forbs, and grasses. This range site consists of somewhat poorly drained, If this site is in excellent condition, the total annual moderately permeable soils. It covers about 6,700 acres. forage production is about 1,400 pounds per acre when These soils are affected by saline or alkali salts, or growing conditions are favorable and 700 pounds per acre both, and by flooding, ponding, and a water table at a in years when growing conditions are poor. About 90 depth of 21/2 to 4 feet. Some soils have a hardpan below a percent of the annual production is from plants that depth of 40 inches and are very slowly permeable. produce forage for cattle, sheep, and horses. This site is Elevation ranges from 900 to 2,200 feet. well suited to grazing in spring, fall, and winter. Deer The annual precipitation is 11 to 18 inches. Most of use this site for grazing in winter and early spring, and it is received between October 1 and June 1. Additional chukar use steep, rocky areas of it as habitat. moisture is generally available because of the bottom Bluebunch wheatgrass, Idaho fescue, big bluegrass, land position of this site. The summers are hot and giant wildrye, prairie junegrass, and Thurber needlegrass dry. Plant growth is limited by the high salt content decrease with continued overgrazing. As these plants of the soils. The period between May 1 and August 1 decrease, threadleaf sedge, Sandberg bluegrass, lupine, is favorable for plant growth. and rabbitbrush increase. Undesirable weeds and The potential plant community is characterized by annuals such as cheatgrass brome, medusahead, ripgut grasses. Giant wildrye makes up 50 percent of the air- brome, plantain, Jim Hill and tansey mustards, tarweed, dry herbage, and saltgrass makes up 25 percent. The thistles, and common mullein become more abundant as rest of the plant community is alkali bluegrass, alkali the range deteriorates. cordgrass, foxtail barley, rushes, sedges, potentilla, Range seeding is needed if the site is in poor yarrow, iris, greasewood, and rabbitbrush. condition. Most soils in this site are suitable for If the site is in excellent condition, the total annual mechanical seedbed preparation. Perennial grasses and forage production is about 4,000 pounds per acre when legumes can be seeded with regular grain drills. growing conditions are favorable and 2,000 pounds per Selection of grasses to help balance seasonal forage acre when growing conditions are poor. About 95 shortages is important for soil stabilization and for percent of the annual production is plants that animal production. produce forage for livestock. Where adjacent to open water, this site provides excellent nesting for ringneck LOAMY RANGE SITE (L-3) pheasants and waterfowl. This range site includes well drained, moderately Giant wildrye decreases rapidly with continued permeable to moderately slowly permeable silt loams or overgrazing, repeated burning, or mowing. Saltgrass, very cobbly silt loams. It covers about 28,000 acres of alkali cordgrass, potentilla, yarrow, and rabbitbrush upland hills, ridges, side slopes, and foot slopes. The soils increase as the giant wildrye is killed out. Weedy plants are 20 inches to more than 60 inches deep to such as bassia, lambsquarter, and dandelion become bedrock. The available water capacity is mostly mod- established with continued abuse of the site. Range seeding to tall wheatgrass is desirable where erate to moderately high. Slopes are mostly 0 to 30 cent; Sandberg bluegrass, prairie junegrass, and percent but range from 0 to 55 percent. Generally, these threadleaf sedge make up 8 percent; and arrowleaf soils are on south- and -,vest-facing side slopes. balsamroot, lupine, wild buckwheat, milkvetch, and yarrow The annual precipitation is 14 to 23 inches. About 80 make up 7 percent. The rest of the plant community is percent of this moisture is received between October 1 rabbitbrush and threetip sagebrush. and June 15. The summers are hot and dry. The If the site is in excellent condition, the total annual period between May 1 and July 15 is favorable for forage production is about 1,600 pounds per acre when plant growth. growing conditions are favorable and 750 pounds per acre The potential plant community is characterized by when growing conditions are unfavorable. About 85 scattered ponderosa pine and hawthorne and an understory percent of the annual production is from plants that of grasses, forbs, and shrubs. Idaho fescue makes up 35 produce forage for domestic livestock. This site is percent, by weight, and bluebunch wheatgrass makes suitable for grazing in late spring, early summer, and up 35 percent. The rest of the plant community is fall. It is used by wildlife throughout the year. Sandberg, Kentucky, Canada, and big bluegrass, annual Idaho fescue and bluebunch wheatgrass decrease with grasses, arrowleaf balsamroot, lupine, biscuitroot, continued overgrazing or repeated burning; Sandberg milkvetch, wild buckwheat, fleabane, yarrow, clover, bluegrass, wild buckwheat, lupine, milkvetch, yarrow, and arnica, potentilla, geranium, annual forbs, snowberry, rabbitbrush increase. Undesirable grasses and weeds, rose, threetip sagebrush, and rabbitbrush. cheatgrass brome, medusahead, yellow starthistle, and If this site is in excellent condition, the total annual annual plantain are common invaders when the vegetation forage production is about 2,400 pounds per acre when is in poor condition. growing conditions are favorable and 1,090 pounds per Range seeding is suitable in areas that are in poor acre when growing conditions are poor. About 85 percent condition and on slopes where equipment can be used. of the annual production is from plants that produce Seedings of grasses and legumes that provide forage forage for cattle and horses. This site is suitable for for the desired period of use and that help to control grazing in late spring, summer, and fall. It also erosion are suitable. provides habitat for deer, partridge, quail, rabbits, and NORTH EXPOSURE RANGE SITE (N-2) coyotes. This range site consists of well drained, moderately Idaho fescue and bluebunch wheatgrass decrease with steep to very steep, moderately permeable silt loans. It continued overgrazing or repeated burning. As those covers about 8,700 acres. The soils are on upland plants decrease, less productive bluegrasses, lupine, north- and east-facing sides of major drainage-ways. wild buckwheat, potentilla, snowberry, and rabbitbrush mostly in the southeastern part of the county. Slopes increase. Thistles, medusahead, yellow starthistle, and are 25 to 65 percent. The available water capacity is other annual grasses and weeds become abundant when moderately high or high. Elevation ranges from 1,100 to the site is badly depleted. 2,600 feet. Range seeding is needed if the site is in poor condition. The annual precipitation is 15 to 20 inches. About 80 A summer fallow seedbed is suitable, but fail plowing percent of this moisture is received between October 1 and spring planting are often used, depending on the and June 1. Snow blown from adjacent ridgetops degree of elimination of competing vegetation. accumulates on north-facing slopes and adds to the Selecting plants for seedings to help balance seasonal moisture supply. The cooler temperature of the soils forage shortages are important for soil stabilization and and the protection they receive from wind reduce the loss for livestock or wildlife requirements. of moisture by evaporation. The summers are warm and dry. The period between May 10 and July 30 is NORTH EXPOSURE RANGE SITE (N-1) This range site consists of well drained, moderately steep favorable for plant growth. and very steep, moderately permeable, cobbly silt loans The potential plant community is characterized by a and silt loams. It covers about 24,000 acres. The soils shrubby overstory and an understory of grasses and are on north- and northeast-facing upland hills, ridges, forbs. Idaho fescue makes up 70 percent, by weight, of and side slopes. They are 20 to more than 60 inches the vegetation, and bluebunch wheatgrass and deep to bedrock. The available water capacity is Sandberg bluegrass each make up 5 percent. The rest of moderate to high. Elevation ranges from 600 to 2,500 the plant community is mainly Columbia needlegrass, feet. prairie junegrass, big bluegrass, elk sedge, potentilla, The annual precipitation is 11 to 16 inches. About 80 fleabane, arrowleaf balsamroot, yarrow, lupine, phlox, wild percent of this moisture is received between October 1 and buckwheat, milkvetch, and annual grasses and weeds and June 1. Snow blown from adjacent ridgetops an overstory of rose, snowberry, currant, serviceberry, accumulates on the north- and northeast-facing slopes and and hawthorn. adds to the moisture supply. The cooler temperature of the If this site is in excellent condition, the total annual soils and the protection they receive from wind reduce the forage production is about 2,000 pounds per acre when loss of moisture by evaporation. The summers are hot and growing conditions are favorable and 1,500 pounds per dry. The period between April 15 and July 1 is favorable acre when growing conditions are unfavorable. About 85 for plant growth. percent of the annual production is from plants that The potential plant community is characterized by an produce forage for livestock. This site is suitable for overstory of threetip sagebrush and rabbitbrush and an grazing in late spring, summer, and fall. It provides understory of grasses and forbs. Idaho fescue makes up 45 habitat for big game and other wildlife species percent, by weight, of the total annual herbage production; throughout the year. bluebunch wheatgrass makes up 35 per- Idaho fescue, bluebunch wheatgrass, big bluegrass, and elk sedge decrease with continued overgrazing or can be used. Consideration should be given to leaving repeated burning; Sandberg bluegrass, Kentucky blue- key areas of brush cover for wildlife and watershed grass, arrowleaf balsamroot, lupine, yarrow, wild buck- protection along drainageways and on steep hillsides. wheat, phlox, milkvetch, rabbitbrush, rose, snowberry, Grasses and legumes selected for seeding should provide currant, serviceberry, and hawthorn increase. Weedy forage for livestock and big game during periods of plants such as medusahead, annual bromes, yellow low forage supply and should help to control soil starthistle, and goatweed invade when the site is in erosion. poor condition. SANDY LOAM RANGE SITE Range seeding is suitable when this site is in poor This range site consists of somewhat excessively condition and where slopes permit use of equipment. drained, nearly level to steep, moderately permeable or Seeding of grasses that provide forage for the desired moderately rapidly permeable sandy loams that are period of use and that help to control soil erosion is underlain by coarse or very coarse sand below a depth suitable. of 20 to 40 inches. It covers about 2,600 acres of terraces and terrace breaks in channeled scablands along major NORTH EXPOSURE RANGE SITE (N-3) drainageways. The available water capacity is low to This range site consists of well drained and moder- moderately high. Slopes are mostly south- and southwest- ately well drained, moderately permeable and moderately facing and are 0 to 40 percent. Elevation ranges from slowly permeable silt loams. It covers about 1,200 acres 600 to 2,000 feet. of loess uplands, mostly in the eastern part of the The annual precipitation is 11 to 15 inches. Most county. Available water capacity is high. Slopes are of this moisture is received between October 1 and May 40 to 55 percent. Exposures are north and east. 1. Because of the low to moderately high available water Elevation ranges from 2,000 to 3,000 feet. capacity and the moderate and moderately rapid The annual precipitation is 18 to 23 inches. About permeability, some moisture is lost through percolation 80 percent of this moisture is received between October 1 and evaporation. The summers are hot and dry. The and June 1. Snow blown from adjacent ridgetops period between March 15 and June 15 is favorable for accumulates on the north- and east-facing side slopes plant growth. and adds to the moisture supply. Protection from wind The potential plant community is characterized by and the cooler temperature of the soils reduce the loss scattered shrubs and an understory of grasses and of moisture by evaporation and thus lengthen the grow- forbs. Bluebunch wheatgrass makes up 50 percent of ing season. The summers are warm and dry. The period the vegetation, by weight. The rest of the plant com- between May 15 and July 30 is favorable for the growth of munity is 20 percent needleandthread; 5 percent Thur- plants. ber needlegrass; 5 percent Sandberg bluegrass; and 5 The potential plant community is characterized by a percent prairie junegrass, Indian ricegrass, Idaho fes- shrubby overstory and an understory of grasses and cue, and annual grasses. Forbs make up 10 percent and forbs. Idaho fescue makes up 45 percent of the vegetation, consist of hawksbeard, biscuitroot, arrowleaf balsamroot, by weight; bluebunch wheatgrass makes up 30 wild buckwheat, milkvetch, and annual forbs. Shrubs percent; snowberry makes up 10 percent; and rose and make up 5 percent and consist of rabbitbrush, big spirea make up 5 percent each. The rest of the plant sagebrush, and bitterbrush. community is Sandberg, Kentucky, and big bluegrasses, If this site is in excellent condition, the total annual timothy, pinegrass, elk sedge, arrowleaf balsamroot, forage production is about 1,000 pounds per acre when potentilla, lupine, geranium, wild buckwheat, milkvetch, growing conditions are favorable and 400 pounds per acre strawberry, yarrow, aster, snowberry, ninebark, when growing conditions are unfavorable. About 90 hawthorn, willow, and a few ponderosa pine. percent of the annual production is from plants that If this site is in excellent condition, the total annual produce forage for cattle, sheep, deer, and horses. This forage production is about 2,600 pounds per acre in site is suitable for grazing in late fall, in winter, and years when growing conditions are favorable and 2,000 in early spring. The soil tends to be loose and sandy, pounds per acre in years when growing conditions are and it is not suitable for grazing during the dry unfavorable. About 75 percent of the annual production is summer. from plants that produce forage for livestock. This site Bluebunch wheatgrass, Idaho fescue, prairie junegrass, is suitable for grazing livestock in summer and fall Indian ricegrass, Thurber needlegrass, hawksbeard, and for wildlife habitat throughout the year. The shrub biscuitroot, and bitterbrush decrease with continued species are important to deer and other wildlife species. overgrazing or repeated burning; Sandberg bluegrass, Idaho fescue, bluebunch wheatgrass, elk sedge, pine- needleandthread, arrowleaf balsamroot, wild buckwheat, grass, and big bluegrass decrease with continued over- milkvetch, lupine, phlox, and rabbitbrush increase. grazing or repeated burning. Kentucky and Sandberg Undesirable weeds such as cheatgrass brome, cocklebur, bluegrasses, arrowleaf balsamroot, potentilla, lupine, wild china lettuce, Russian thistle, mustard, medusahead, buckwheat, yarrow, snowberry, spirea, and ninebark and yellow starthistle invade the site if the range is in increase when the range is abused. When this site is in poor condition. poor condition, weedy plants, cheatgrass brome, soft If the site is in poor condition, range seeding and chess, medusahead, goatweed, yellow starthistle, thistle, minimal cultivation are needed. common mullein, and rabbitbrush invade as climax plants are killed out. SHALLOW RANGE SITE (S-2) Range seeding is suitable in areas that are in poor This range site consists of well drained, nearly level condition and on slopes where conventional equipment to very steep, moderately permeable cobbly silt loams that are 10 to 20 inches deep to basalt. It covers about grass make up 6 percent. The rest of the plant com- 60,000 acres of channeled scablands and side slopes munity is biscuitroot, arrowleaf balsamroot, lupine, wild along major drainageways. The available water capacity is buckwheat, milkvetch, yarrow, and fleabane. Shrubs low. Slopes are mostly west- and south-facing and are 0 are snowberry, threetip sagebrush, and rabbitbrush. to 65 percent. Areas of Rock outcrop are common. If this site is in excellent condition, the total annual Elevation ranges from 600 to 2,600 feet. herbage production is 1,200 pounds per acre when The annual precipitation is 11 to 15 inches. About 80 growing conditions are favorable and 550 pounds per acre percent of this moisture is received between October 1 when growing conditions are unfavorable. About 90 and June 1. This site is dry, and plant growth is percent of the annual production is from plants that limited by the shallowness of the soil and the loss of produce forage for cattle, horses, and deer. The site is moisture through evaporation. The summers are hot suited to grazing livestock during spring or fall. It and dry. The period between April 1 and June 1 is provides habitat for chukar. favorable for plant growth. Bluebunch wheatgrass and Idaho fescue decrease with The potential plant community is characterized by continued overgrazing or repeated burning; Sandberg sparse patchy grasses, forbs, and few shrubs. Blue- bluegrass, arrowleaf balsamroot, biscuitroot, lupine, bunch wheatgrass makes up 65 percent of the vegetation, and wild buckwheat increase. Undesirable plants such by weight, and Sandberg bluegrass makes up 10 percent. as cheatgrass brome, Japanese brome, medusahead, The rest of the plant community is Thurber needlegrass, thistle, yellow starthistle, and rabbitbrush invade the arrowleaf balsamroot, biscuitroot, fleabane, lupine, site if the range deteriorates. yarrow, phlox, wild buckwheat, and rabbitbrush. Range seeding is difficult because the soils are too If this site is in excellent condition, the total annual shallow and stony. forage production is about 700 pounds per acre when VERY SHALLOW RANGE SITE growing conditions are favorable and 400 pounds per acre This range site consists of well drained, nearly level when growing conditions are unfavorable. About 90 to moderately steep, moderately slowly permeable percent of the annual production is from plants that cobbly loams that are 6 to 10 inches deep over bedrock. It produce forage for cattle, sheep, and horses and covers about 8,600 acres of channeled scablands and side occasionally for deer. The site is suitable for grazing in slopes of major drainageways. Slopes face mostly south spring, fall, and winter. Grazing animals must be and west and are 0 to 30 percent. Elevation ranges periodically excluded during plant growth to maintain or from 600 to 2,600 feet. improve range vegetation. This site provides habitat for The annual precipitation is 12 to 16 inches. Most of chukars. this moisture is received between October 1 and June 1. Bluebunch wheatgrass decreases with continued The summers are hot and dry. The period between overgrazing or repeated burning. Sandberg bluegrass, April 1 and May 15 is favorable for plant growth. Thurber needlegrass, biscuitroot, and rabbitbrush increase. The potential plant community is characterized by low- Undesirable weeds and annual grasses such as cheatgrass growing shrubs, grasses, and forbs. Sandberg bluegrass brome, medusahead, and yellow starthistle invade the makes up 50 percent of the vegetation, by weight; stiff site as the potential plant community deteriorates. sagebrush makes up 20 percent; and wild buckwheat Soils in this site are too stony, steep, and shallow for makes up 15 percent. Bluebunch wheatgrass, Thurber range seeding. Vegetation improvement is slow but can be needlegrass, squirreltail, and annual grasses make up 5 obtained through good range management. percent. Forbs make up 10 percent and consist of hooker and serrated balsamroot, fleabane, phlox, violet, SHALLOW RANGE SITE (S-3) and annual forbs. This range site consists of well drained, nearly level to If this site is in excellent condition the total annual very steep, moderately slowly permeable cobbly silt loams forage production is about 300 pounds per acre when that are 20 to 40 inches deep over bedrock. It covers growing conditions are favorable and 175 pounds per about 6,400 acres of uplands along major drainageways acre when growing conditions are unfavorable. About 70 in the eastern part of the county. The available water percent of the annual production is from plants that capacity is low. Slopes are mostly 30 to 65 percent but produce forage for cattle, sheep, deer, and horses. The range from 3 to 65 percent, and they face south and site is suitable for grazing livestock early in spring and west. Elevation ranges from 1,600 to 3,000 feet. for game animals during winter and early spring. It The annual precipitation is 18 to 23 inches. About 80 provides habitat for chukar. percent of this moisture is received between October 1 and Sandberg bluegrass and stiff sagebrush decrease with June 30. This site is droughty, and plant growth is continued overgrazing or repeated burning; limited by the shallowness and the low available water Balsamroot, biscuitroot, fleabane, and phlox increase. capacity of the soil. The summers are warm and dry. The Undesirable weeds and annuals invade the site if the period between May 1 and July 15 is favorable for plant range deteriorates. growth. Range seeding is not practical because the soil is too The potential plant community is characterized by shallow and stony and the potential yield is too low. scattered shrubs and an understory of grasses and forbs. Bluebunch wheatgrass makes up 50 percent of the WET MEADOW RANGE SITE vegetation, by weight; Idaho fescue makes up 25 percent; This range site consists of somewhat poorly drained, and Sandberg, Kentucky, and Canada blue moderately permeable to very slowly permeable silt loams and silty clay loams. It covers about 4,500 acres

the same general kinds of woodland management and have of bottom lands. The available water capacity is high. The about the same potential productivity. water table is at a depth of 6 to 60 inches, and the soils The first part of the symbol, a number, indicates the are subject to flooding in winter and spring. Elevation potential productivity of the soils for important trees (4). ranges from 1,500 to 2,800 feet. The number 1 indicates very high productivity; 2, high; The annual precipitation is 15 to 23 inches. Most of it 3, moderately high; 4, moderate ; and 5, low. The second is received between October 1 and June 15. Additional part of the symbol, a letter, indicates the major kind of moisture is generally available because of the bottom soil limitation. The letter x indicates stoniness or land position of this site. The summers are hot and dry, rockiness; w, excessive water in or on the soil ; t, toxic but plant growth is not limited by lack of moisture. substances in the soil; d, restricted root depth; c, clay in The period between May 1 and August 15 is favorable the upper part of the soil; s, sandy texture; f, high for plant growth. content of coarse fragments in the soil profile; and r, The potential plant community is characterized by steep slopes. The letter o indicates no significant water-tolerant grasses, sedges, rushes, cattails, and a limitations or restrictions. If a soil has more than one few willows. Tufted hairgrass makes up 30 percent of limitation, priority in placing the soil into a the air-dry herbage ; reed canarygrass makes up 25 limitation class is in the order in which the letters percent; redtop makes up 10 percent; sedge makes up 5 are listed above-x, w, t, d, c, s, f, and r. percent; and rush, quackgrass, timothy, Kentucky In table 3 the soils are also rated for a number of bluegrass, foxtail barley, cattails, slender hairgrass, factors to be considered in management. The ratings of slender wheatgrass, meadow foxtail, and annual grasses slight, moderate, and severe are used to indicate the make up 18 percent. Forbs make up 10 percent and degree of major soil limitations. consist of potentilla, mint, water buttercup, arrowgrass, Ratings of the hazard of erosion indicate the risk of and water hemlock. Shrubs make up 2 percent and loss of soil in well managed woodland. The risk is consist of willow and aspen. slight if the expected soil loss is small ; moderate if If the site is in excellent condition, the total annual some measures are needed to control erosion during forage production is about 6,000 pounds per acre when logging and road construction ; and severe if intensive growing conditions are favorable and 3,000 pounds per management or special equipment and methods are needed acre when growing conditions are poor. About 95 percent to prevent excessive loss of soil. of the annual production is from plants that produce Ratings of equipment limitation reflect the charac- forage for livestock. This range site provides excellent teristics and conditions of the soil that restrict use of nesting cover for water birds. the equipment generally needed in woodland management Tufted hairgrass decreases rapidly with continued or harvesting. A rating of slight indicates that use of overgrazing, repeated burning, or mowing. Other plants equipment is not limited to a particular kind of that decrease are reed canarygrass, slender wheatgrass, equipment or time of year; moderate indicates a short timothy, and meadow foxtail. As these plants decrease, seasonal limitation or need for some modification in slender hairgrass, redtop, sedge, foxtail barley, rushes, management or equipment; severe indicates a seasonal quackgrass, Kentucky bluegrass, arrowgrass, cattail, limitation, a need for special equipment or manage- potentilla, mint, iris, buttercup, willows, and aspen ment, or a hazard in the use of equipment. increase. Weedy plants such as hairgrass, dock, fireweed, Seedling mortality ratings indicate the degree that dandelion, bull thistle, and burdock, become established as the soil affects expected mortality of planted tree seedlings the vegetation declines. when plant competition is not a limiting factor. The Range seeding to reed canarygrass is suitable where ratings are for seedlings from good planting stock that this range has deteriorated. are properly planted during a period of sufficient rainfall. A rating of slight indicates that the expected mortality of Woodland the planted seedlings is less than 25 percent; moderate, 25 to 50 percent; and severe, more than 50 percent. About 10,000 acres, or less than 1 percent, of Whit- Ratings of plant competition indicate the degree to man County is in woodland. The areas are privately which undesirable plants are expected to invade or grow owned. The important species is ponderosa pine with if openings are made in the tree canopy. The some Douglas-fir and western larch. The stands are invading plants compete with native plants or planted generally unevenly aged. Logging is generally on a selective seedlings by impeding or preventing their growth. A basis to a diameter limit and varies with the demand rating of slight indicates little or no competition from for stumpage. Logs are shipped to mills outside the other plants; moderate indicates that plant competition is survey area for processing. expected to hinder the development of a fully stocked Woodland in this survey area is also used for grazing, stand of desirable trees ; severe means that plant recreation, wildlife habitat, and watershed protection. competition is expected to prevent the establishment of Table 3 contains information useful to woodland a desirable stand unless the site is intensively prepared, owners or forest managers planning use of soils for weeded, or otherwise managed for the control of wood crops. Mapping unit symbols for those soils suitable undesirable plants. for wood crops are listed alphabetically by soil name, The potential productivity of merchantable trees on a and the ordination symbol for each soil is given. All soils soil is expressed as a site index. This index is the bearing the same ordination symbol require average height, in feet, that dominant and codominant ROBERT J. OLSON, woodland conservationist, Soil Conservation trees of a given species attain in a specified number Service, assisted in preparing this section.

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

of years. The site index applies to fully stocked, even Table 4 shows the height that locally adapted trees aged, unmanaged stands. and shrubs are expected to reach on various kinds of Trees to plant are those that are suitable for com- soil in 20 years. The estimates in table 4, based on mercial wood production and that are suited to the measurements and observation of established plantings soils. that have been given adequate care, can be used as a guide in planning windbreaks and screens. Additional Windbreaks and Environmental Plantings information about planning windbreaks and screens and the planting and care of trees can be obtained from the Windbreaks are established to protect livestock, local office of the Soil Conservation Service or the buildings, and yards from winds and snow. Windbreaks Extension Service or from local nurserymen. also help to protect fruit trees and gardens, and they furnish habitat for wildlife. Several rows of broad- Wildlife Habitat leaved and coniferous species provide the most protection. Soils directly affect the kind and amount of vegetation Narrow field windbreaks can be made at right angles to that is available to wildlife as food and cover, and they the prevailing wind on the windward side of the affect the development of water impoundments. The kind hillcrest. These prevent deep snowdrifts from forming on and abundance of wildlife that populate an area depend the steep, north-facing side slopes. Some of these largely on the amount and distribution of food, cover, slopes are planted to trees and shrubs to prevent slip- and water. If any one of these elements is missing, page and to decrease erosion. inadequate, or inaccessible, wildlife will either be Environmental plantings help to beautify and screen scarce or will not inhabit the area. homes and other buildings and to abate surrounding If the soils have potential, wildlife habitat can be noise. Healthy planting stock of suitable species planted created or improved by planting appropriate vegeta- properly on a well prepared site and maintained in tion, by properly managing the existing plant cover, good condition can insure a high degree of plant IVAN L . LINES, JR., biologist, Soil Conservation Service, assisted in survival. preparing this section.

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

and by fostering the natural establishment of attention are required for satisfactory results. A rating of desirable plants. poor means that limitations are severe for the designated In table 5 the soils in the survey area are rated element or kind of wildlife habitat. Habitat can be created, according to their potential to support the main kinds of improved, or maintained in most places, but management is wildlife habitat in the area. This information can be used in: difficult and requires intensive effort. A rating of very poor (1) planning the use of parks, wildlife refuges, nature means that restrictions for the element or kind of wildlife study areas, and other developments for wildlife; (2) habitat are very severe, and that unsatisfactory results can selecting soils that are suitable for creating, improving, or be expected. Wildlife habitat is impractical or even maintaining specific elements of wildlife habitat; (3) impossible to create, improve, or maintain on soils determining the intensity of management needed for each having such a rating. element of the habitat; and (4) determining areas that are The elements of wildlife habitat are briefly described suitable for acquisition to manage wildlife. in the following paragraphs. The potential of the soil is rated good, fair, poor, or very Grain and seed crops are seed-producing annuals poor. A rating of good means that the element or kind of used by wildlife. Examples are wheat, oats, barley, and wildlife habitat is easily created, improved, or maintained. peas. Major soil properties that affect the growth of grain Few or no limitations affect management, and satisfactory and seed crops are depth of the root zone, texture of the results can be expected if the soil is used for the designated surface layer, available water capacity, wetness, slope, purpose. A rating of fair means that the element or kind of surface stoniness, and flood hazard. Soil temperature and soil wildlife habitat can be created, improved, or maintained in moisture are also considerations. most places. Moderate intensity of management and Grasses and legumes are domestic grasses and her fairly frequent baceous legumes that are planted for wildlife food and cover. Examples are fescue, bluegrass, bromegrass, or a mixture of both, with an understory of grasses, orchardgrass, clover, alfalfa, sweetclover, and trefoil. legumes, and wild herbaceous plants. Examples of Major soil properties that affect the growth of grasses wildlife attracted to this habitat are thrushes, vireos, and legumes are depth of the root zone, texture of the woodpeckers, squirrels, raccoons, and deer. surface layer, available water capacity, wetness, sur- Wetland habitat consists of water-tolerant plants and face stoniness, flood hazard, and slope. Soil tempera- shallow open water in marshes, wetlands, and sloughs. ture and soil moisture are also considerations. Examples of wildlife attracted to this habitat are ducks, Wild herbaceous plants are native or naturally es- geese, herons, shore-birds, kingfishers, beaver, muskrat, tablished herbaceous grasses and forbs, including and mink. weeds, that provide food and cover for wildlife. Examples Rangeland habitat consists of wild herbaceous plants are wheatgrass, cheatgrass, fescue, sunflower, thistles, and shrubs in range. Examples of wildlife attracted to dandelions, and balsamroot. Major soil properties that this habitat are deer, chukar, Hungarian partridge, affect the growth of these plants are depth of the root meadowlark, coyote, golden eagle, and ferruginous zone, texture of the surface layer, available water hawk. capacity, wetness, surface stoniness, and flood hazard. Soil temperature and soil moisture are also Engineering considerations. Coniferous plants are cone-bearing trees, shrubs, or This section provides information about the use of ground cover that furnish habitat or supply food in soils for building sites, sanitary facilities, construction the form of browse, seeds, or fruitlike cones. Examples materials, and water management. Among those who can are pine, spruce, fir, cedar, and juniper. Major soil benefit from this section are engineers, landowners, properties that affect the growth of coniferous plants community decision makers and planners, town and are depth of the root zone, available water capacity, city managers, land developers, builders, contractors, and and wetness. farmers and ranchers. Shrubs are bushy, woody plants that produce fruits, The ratings in tables in this section are based on buds, twigs, bark, or foliage used by wildlife or that test data and estimated data in the "Soil Properties" provide cover and shade for some species of wildlife. section. The ratings were determined jointly by soil Examples are willow, serviceberry, caragana, snow- scientists and engineers of the Soil Conservation Service berry, sagebrush, rabbitbrush, and native roses. Major using known relationships between the soil properties and soil properties that affect the growth of shrubs are the behavior of soils in various engineering uses. depth of the root zone, available water capacity, Among the soil properties and site conditions salinity, and moisture. identified by the soil survey and used in determining Wetland plants are annual and perennial wild her- the ratings in this section are grain-size distribution, baceous plants that grow on moist or wet sites, exclu- liquid limit, plasticity index, soil reaction, depth to and sive of submerged or floating aquatics. They produce hardness of bedrock within 5 or 6 feet of the surface, food or cover for wildlife that uses wetland as its soil wetness characteristics, depth to a seasonal water habitat. Examples of wetland plants are smartweed, table, slope, likelihood of flooding, natural soil structure wild millet, rushes, sedges, burreed, and cattail. Major or aggregation, inplace soil density, and geologic soil properties affecting wetland plants are texture of the origin of the soil material. Where pertinent, data about surface layer, wetness, reaction, salinity, slope, and kinds of clay minerals, mineralogy of the sand and silt surface stoniness. fractions, and the kind of absorbed cations were also Shallow water areas are bodies of surface water that considered. have an average depth of less than 5 feet and are use- Based on the information assembled about soil prop- ful to wildlife. They can be naturally wet areas, or erties, ranges of values may be estimated for they can be created by dams or levees or by water erodibility, permeability, corrosivity, shrink-swell control devices in marshes or streams. Examples are potential, available water capacity, shear strength, natural marshes, waterfowl feeding areas, wildlife compressibility, slope stability, and other factors of watering developments, beaver ponds, and other wildlife expected soil behavior in engineering uses. As ponds. Major soil properties affecting shallow water appropriate, these values may be applied to each major areas are depth to bedrock, wetness, surface horizon of each soil or to the entire profile. stoniness, slope, and permeability. The availability of a These factors of soil behavior affect construction and dependable water supply is important if water areas maintenance of roads, airport runways, pipelines, are to be developed. foundations for small buildings, ponds and small dams, The kinds of wildlife habitat are briefly described irrigation projects, drainage systems, sewage and in the following paragraphs. refuse disposal systems, and other engineering works. The Open-land habitat consists of croplands, pastures, ranges of values can be used to (1) select potential meadows, and areas that are overgrown with grasses, residential, commercial, industrial, and recreational herbs, shrubs, and vines. These areas produce grain areas; (2) make preliminary estimates pertinent to and seed crops, grasses and legumes, wild herbaceous construction in a particular area; (3) evaluate alter- plants, and shrubs. The kinds of wildlife attracted to nate routes for roads, streets, highways, pipelines, and these areas include California quail, mourning dove, underground cables; (4) evaluate alternate sites of pheasant, meadowlark, field sparrow, horned lark, kill- deer, cottontail rabbit, rough-legged hawk, and red fox. CHRISTIAN BAFUS, engineer, Soil Conservation Service, assisted in preparing this Woodland habitat consists of hardwoods or conifers section.

or large stones. In addition, excavations are affected location of sanitary landfills, onsite sewage disposal by slope of the soil and the probability of flooding. systems, and other waste disposal facilities; (5) plan Ratings do not apply to soil horizons below a depth of 6 detailed onsite investigations of soils and geology ; (6) feet unless otherwise noted. find sources of gravel, sand, clay, and topsoil; (7) plan In the soil descriptions, the consistence of each soil farm drainage systems, irrigation systems, ponds, horizon is defined, and the presence of very firm or terraces, and other structures for soil and water con- extremely firm horizons, generally difficult to excavate, is servation; (8) relate performance of structures already indicated. built to the properties of the kinds of soil on which Dwellings and small commercial buildings, referred they are built so that performance of similar to in table 6, are built on undisturbed soil and have structures on the same or a similar soil in other foundation loads of a dwelling no more than 3 stories locations can be predicted; and (9) predict the high. Separate ratings are made for small commercial trafficability of soils for cross-country movement of buildings without basements and for dwellings with vehicles and construction equipment. and without basements. For such structures, soils Data presented in this section are useful for land should be sufficiently stable that cracking or sub- use planning and for choosing alternative practices or sidence from settling or shear failure of the foundation general designs that will overcome unfavorable soil do not occur. These ratings were determined from es- properties and minimize soil-related failures. Limitations timates of the shear strength, compressibility, and to the use of these data, however, should be well shrink-swell potential of the soil. Soil texture, plasticity understood. First, the data are generally not presented and in-place density, potential frost action, soil for soil material below a depth of 5 or 6 feet. Also, wetness, and depth to a seasonal high water table because of the scale of the detailed map in this soil were also considered. Soil wetness and depth to a sea- survey, small areas of soils that differ from the dominant sonal high water table indicate potential difficulty in soil may be included in mapping. Thus, these data do providing adequate drainage for basements, lawns, and not eliminate the need for onsite investigations and gardens. Depth to bedrock, slope, and the large stones testing. in or on the soil are also important considerations in The information is presented mainly in tables. Table the choice of sites for these structures and were 6 shows, for each kind of soil, ratings of the degree considered in determining the ratings. Susceptibility to and kind of limitations for building site development; flooding is a serious limitation. table 7, for sanitary facilities; and table 9, for water Local roads and streets, referred to in table 6, have management. Table 8 shows the suitability of each kind an all-weather surface that can carry light to medium of soil as a source of construction materials. traffic all year. They consist of a subgrade of the The information in the tables, with the soil map, underlying soil material; a base of gravel, crushed rock soil descriptions, and other data provided in this survey, fragments, or soil material stabilized with lime or can be used to make additional interpretations and to cement; and a flexible or rigid surface, commonly asphalt construct interpretive maps for specific uses of land. or concrete. The roads are graded with soil material Some of the terms used in this soil survey have at hand, and most cuts and fills are less than 6 feet different meanings in soil science and in engineering; deep. the Glossary defines many of these terms. The load-supporting capacity and the stability of the soil as well as the quantity and workability of fill Building site development material available are important in design and con- struction of roads and streets. The AASHTO and The degree and kind of soil limitations that affect Unified classifications of the soil and the soil texture, shallow excavations, dwellings with and without base- density, shrink-swell potential, and potential frost ments, small commercial buildings, and local roads and action are indicators of the traffic-supporting capacity streets are indicated in table 6. A slight limitation used in making the ratings. Soil wetness, flooding, indicates that soil properties are favorable for the slope, depth to hard rock or very compact layers, and specified use; any limitation is minor and easily overcome. content of large stones, all of which affect stability and A moderate limitation indicates that soil properties and ease of excavation, were also considered. site features are unfavorable for the specified use, but the limitations can be overcome or minimized by special Sanitary facilities planning and design. A severe limitation indicates one or more soil properties or site features are so unfavorable Favorable soil properties and site features are needed or difficult to overcome that a major increase in for proper functioning of septic tank absorption fields, construction effort, special design, or intensive sewage lagoons, and sanitary landfills. The nature of the maintenance is required. For some soils rated severe, soil is important in selecting sites for these facilities such costly measures may not be feasible. and in identifying limiting soil properties and site Shallow excavations are used for pipelines, sewer features to be considered in design and installation. lines, telephone and power transmission lines, basements, Also, those soil properties that deal with the ease of open ditches, and cemeteries. Such digging or trenching excavation or installation of these facilities will be of is influenced by the soil wetness of a high seasonal interest to contractors and local officials. Table 7 water table, the texture and consistence of soils, the shows the degree and kind of limitations of each soil tendency of soils to cave in or slough, and the for these uses and for use of the soil as daily cover for presence of very firm, dense soil layers, bedrock, landfills. If the degree of soil limitation is indicated by the rating slight, soils are favorable for the specified use

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

and limitations are minor and easily overcome; if Some soils are underlain by loose sand and gravel moderate, soil properties or site features are unfavor- or fractured bedrock at a depth less than 4 feet below able for the specified use, but limitations can be over- the tile lines. In these soils the absorption field does come by special planning and design; and if severe, soil not adequately filter the effluent, and as a result, properties or site features are so unfavorable or diffi- ground water supplies in the area may be contami- cult to overcome that major soil reclamation, special nated. Soils that have a hazard of inadequate filtration are designs, or intensive maintenance are required. indicated by footnotes in table 7. Septic tank absorption fields are subsurface systems of Percolation tests are performed to determine the tile or perforated pipe that distribute effluent from a septic absorptive capacity of the soil and its suitability for tank into the natural soil. Only the soil horizons septic tank absorption fields. These tests should be between depths of 18 and 72 inches are evaluated for this performed during the season when the water table is use. The soil properties and site features considered are highest and the soil is at minimum absorptive capacity. those that affect the absorption of the effluent and In many of the soils that have moderate or severe those that affect the construction of the system. limitations for septic tank absorption fields, it may be Properties and features that affect the absorption of possible to install special systems that lower the sea- the effluent are permeability, depth to a seasonal high sonal water table or to increase the size of the water table, depth to bedrock, and susceptibility to absorption field so that satisfactory performance is flooding. Stones, boulders, and a shallow depth to achieved. bedrock interfere with installation. Excessive slope may Sewage lagoon areas are shallow ponds constructed cause lateral seepage and surfacing of the effluent in to hold sewage while bacteria decompose the solid and downslope areas. Also, soil erosion and soil slippage are liquid wastes. Lagoons have a nearly level flow area hazards where absorption fields are installed in sloping surrounded by cut slopes or embankments of com- soils. pacted, nearly impervious soil material. They generally are designed so that depth of the sewage is 2 to 5 feet.

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

Impervious soil at least 4 feet thick for the lagoon are deep to bedrock and a seasonal water table, are floor and sides is required to minimize seepage and free of large stones and boulders, and are not subject to contamination of local ground water. Soils that are flooding. In areas where the seasonal water table is very high in organic matter and those that have stones high, water seeps into the trenches and causes problems and boulders are undesirable. Unless the soil has very in excavating and filling the trenches. Also, seepage into slow permeability, contamination of local ground water is the refuse increases the risk of pollution of ground a hazard in areas where the seasonal high water table water. Clayey soils are likely to be sticky and difficult is above the level of the lagoon floor. In soils where to spread. Sandy or gravelly soils generally have rapid the water table is seasonally high, seepage of ground permeability that might allow noxious liquids to water into the lagoon can seriously reduce its capacity for contaminate local ground water. liquid waste. Slope, depth to bedrock, and susceptibility Unless otherwise stated, the ratings in table 7 apply to flooding also affect the location of sites for sewage only to soil properties and features within a depth of lagoons or the cost of construction. Shear strength and about 6 feet. If the trench is deeper, ratings of slight permeability of compacted soils affect the performance or moderate may not be valid. Site investigation is of embankments. needed before a site is selected. Sanitary landfill is solid waste (refuse) and soil In the area type of sanitary landfill, refuse is placed material placed in successive layers, either in ex- on the surface of the soil in successive layers. The cavated trenches or on the surface of the soil. The limitations caused by soil texture, depth to bedrock, waste is spread, compacted in layers, and covered with and stone content do not apply to this type of landfill. thin layers of soil. Landfill areas are subject to heavy Soil wetness, however, may be a limitation because of vehicular traffic. Ease of excavation, risk of polluting difficulty in operating equipment. ground water, and trafficability affect the suitability Daily cover for sanitary landfills should be soil that is of a soil for this purpose. The best soils have a loamy easy to excavate and spread over the compacted fill or silty texture, have moderate or slow permeability, during both wet and dry weather. Soils that are loamy

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

or silty and free of stones or boulders are better than other tion materials. Each soil is evaluated to the depth observed soils. Clayey soils may be sticky and difficult to spread; and described as the survey is made, generally about 6 feet. sandy soils may be subject to soil blowing. Roadfill is soil material used in embankments for roads. In addition to these features, the soils selected for final The ratings reflect the ease of excavating and working the cover of landfills should be suitable for growing plants. In material and the expected performance of the material after comparison with other horizons, the A horizon in most soils it has been compacted and adequately drained. The has the best workability, more organic matter, and the performance of soil after it is stabilized with lime or cement best potential for growing plants. Thus, for either the is not considered in the ratings, but information about soil area- or trench-type landfill, stockpiling material from the properties that determine such performance is given in the A horizon for use as the surface layer of the final cover is descriptions of soil series. desirable. The ratings apply to the soil profile between the A Where it is necessary to bring in soil material for daily horizon and a depth of 5 to 6 feet. It is assumed that soil or final cover, thickness of suitable soil material that is horizons will be mixed during excavation and spreading. available and depth to a seasonal high water table in Many soils have horizons of contrasting suitability within soils surrounding the sites should be evaluated. Other the profile. The estimated engineering properties in table factors to be evaluated are those that affect reclamation of 11 provide more specific information about the nature of the borrow areas such as slope, erodibility, and potential each horizon that can help determine its suitability for for plant growth. roadfill. Soils rated good have low shrink-swell potential, low Construction materials potential frost action, and few cobbles and stones. They are at least moderately well drained and have slopes of 15 The suitability of each soil as a source of roadfill, percent or less. Soils rated fair have a plasticity index of sand, gravel, and topsoil is indicated in table 8 by ratings of less than 15 and have other limiting good, fair, or poor. The texture, thickness, and organic- matter content of each soil horizon are important factors in rating soils for use as construc

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

features, such as high shrink-swell potential, high potential content. This horizon is designated as A1 or Ap in the soil frost action, steep slopes, wetness, or many stones. If the series descriptions. The absorption and retention of moisture thickness of suitable material is less than 3 feet, the and nutrients for plant growth are greatly increased by entire soil is rated poor, regardless of the quality of the organic matter. Consequently, careful preservation and use suitable material. of material from these horizons are desirable. Sand and gravel are used in great quantities in many kinds of construction. The ratings in table 8 provide guidance Water management for finding probable sources and are based on the probability that soils in a given area contain sizable Many soil properties and site features that affect quantities of sand and gravel. A soil rated good or fair has water management practices have been identified in this soil a layer of suitable material at least 3 feet thick, the top survey. In table 9 soil and site features that affect use of which is within a depth of 6 feet. Coarse fragments are indicated for each kind of soil. This information is of soft bedrock material, such as shale and siltstone, are significant in planning, installing, and maintaining water- not considered to be sand and gravel. Fine grained soils are control structures. not suitable sources of sand and gravel. Pond reservoir areas hold water behind a dam or an The ratings do not take into account depth to the water table embankment. Soils suitable for this use have low seepage or other factors that affect excavation of the material. potential, which is determined by the permeability and depth Descriptions of grain size, kinds of minerals, reaction, and over fractured or permeable bedrock or other permeable stratification are given in the soil series descriptions material. and in the section "Engineering properties." Embankments, dikes, and levees require soil mate Topsoil is used in areas where vegetation is to be rial that is resistant to seepage, erosion, and piping, and established and maintained. Suitability is affected mainly by is of favorable stability, shrink-swell potential, shear the ease of working and spreading the soil material in strength, and compaction characteristics. Stones and organic preparing a seedbed and by the ability of the soil material matter in a soil downgrade the suitability of a soil for use in to sustain the growth of plants. Also considered is the embankments, dikes, and levees. damage that would result to the area from which the Drainage of soil is affected by such soil properties as topsoil is taken. permeability, texture, structure, depth -to claypan or other Soils rated good have at least 16 inches of friable layers that influence rate of water movement, depth to the loamy material at their surface. They are free of water table, slope, stability of ditchbanks, stones, are low in content of gravel and other coarse susceptibility to flooding, salinity and alkalinity, and fragments, and are gently sloping. They are low in availability of outlets for drainage. soluble salts, which can limit plant growth. They are Irrigation is affected by such features as slope, naturally fertile or respond well to fertilization. They are susceptibility to flooding, hazards of water erosion and soil not so wet that excavation is difficult during most of the year. blowing, texture, presence of salts and alkali, depth of the Soils rated fair are loose sandy or firm loamy or root zone, rate of water intake at the surface, clayey soils in which the suitable material is only 8 to 16 permeability of the soil below the surface layer, available inches thick or soils that have appreciable water capacity, need for drainage, and depth to the water amounts of gravel, stones, or soluble salt. table. Soils rated poor are very sandy soils; very firm clayey Terraces and diversions are embankments, or a com- soils; soils with suitable layers less than 8 inches bination of channels and ridges, constructed across a slope to thick, soils having large amounts of gravel, stones, or intercept runoff and allow the water to soak into the soil or soluble salt; steep soils; and poorly drained soils. flow slowly to an outlet. Features that affect suitability of a Although a rating of good is not based entirely on high soil for terraces are uniformity of slope and steepness; depth content of organic matter, a surface horizon is much preferred to bedrock or other unfavorable material; permeability; ease for topsoil because of its organic-matter of establishing vegetation ; and resistance to water erosion, soil blowing, soil slipping, and piping. Grassed waterways are constructed to channel runoff at nonerosive velocities to outlets. Features that affect the use of soils for waterways are slope, perme- the soil over rock should be sufficient to allow necessary ability, erodibility, and suitability for permanent grading. vegetation. The design and layout of paths and trails for walking, horseback riding, and bicycling should require little or no Recreation cutting and filling. The best soils for this use are those that are not wet, are firm after rain, are not dusty The soils of the survey area are rated in table 10 when dry, and are not subject to flooding more than once according to limitations that affect their suitability for during the period of use. They should be moderately camp areas, picnic areas, playgrounds, and paths and sloping and have few or no stones or boulders on the trails. The ratings are based on such restrictive soil surface. features as flooding, wetness, slope, and texture of the surface layer. Not considered in these ratings, but important in evaluating a site, are location and Soil Properties accessibility of the area, size and shape of the area Extensive data about soil properties collected during the and its scenic quality, the ability of the soil to support soil survey are summarized on the following pages. The vegetation, access to water, potential water impoundment two main sources of these data are the many sites available, and either access to public sewer lines or thousands of soil borings made during the course of the capacity of the soil to absorb septic tank effluent. Soils survey and the laboratory analyses of samples selected that are subject to flooding are limited, in varying degree, from representative soil profiles in the field. to recreational use by the duration of flooding and the When the soil scientist makes soil borings during season when it occurs. Onsite assessment of height, field mapping, he can identify several important soil duration, and frequency of flooding is essential in properties. He notes the seasonal soil moisture condi- planning recreational facilities. tion, or the presence of free water and its depth in the In table 10 the limitations of soils are rated as slight, profile. For each horizon, he notes the thickness of the soil moderate, or severe. Slight means that the soil prop- and its color; the texture, or the amount of clay, silt, erties are generally favorable and that the limitations sand, and gravel or other coarse fragments; the are minor and easily overcome. Moderate means that the structure, or natural pattern of cracks and pores in the limitations can be overcome or alleviated by planning, undisturbed soil ; and the consistence of soil in place design, or special maintenance. Severe means that soil under the existing soil moisture conditions. He records properties are unfavorable and that limitations can be the root depth of existing plants, determines soil pH or offset only by costly soil reclamation, special design, reaction, and identifies any free carbonates. intensive maintenance, limited use, or by a combination Samples of soil material are analyzed in the lab- of these measures. oratory to verify the field estimates of soil properties The information in table 10 can be supplemented by and to characterize key soils, especially properties that additional information in other parts of this survey. cannot be estimated accurately by field observation. Especially helpful are interpretations for septic tank Laboratory analyses are not conducted for all soil absorption fields, given in table 7, and interpretations for series in the survey area, but laboratory data for dwellings without basements and for local roads and many of the soil series are available from nearby areas. streets, given in table 6. Based on summaries of available field and laboratory Camp areas require such site preparation as shaping data and listed in tables in this section, are estimated and leveling tent and parking areas, stabilizing roads ranges in engineering properties and classifications and in and intensively used areas, and installing sanitary physical and chemical properties for each major horizon facilities and utility lines. They are subject to heavy of each soil in the survey area. Also, pertinent soil and foot traffic and some vehicular traffic. The best soils water features, engineering test data, and data obtained for this use are mildly sloping and are neither wet from laboratory analyses, both physical and chemical, are nor subject to flooding during the period of use. The presented. surface has few or no stones or boulders, absorbs rain- fall readily but remains firm, and is not dusty when Engineering Properties dry. Strong slopes and stones or boulders can greatly increase the cost of constructing camping sites. Table 11. gives estimates of engineering properties Picnic areas are subject to heavy foot traffic. Most and classifications for the major horizons of each soil in vehicular traffic is confined to access roads and parking the survey area. These estimates are presented as areas. The best soils for use as picnic areas are firm ranges in values most likely to exist in areas where the when wet, are not dusty when dry, are not subject to soil is mapped. flooding during the period of use, and do not have Most soils have, within the upper 5 or 6 feet, hori- slopes or stones or boulders that will increase the cost zons of contrasting properties. Information is presented of shaping sites or of building access roads and parking for each of these contrasting horizons. Depth to the areas. upper and lower boundaries of each horizon in a typical Playgrounds require soils that can withstand intensive profile of each soil is indicated. foot traffic. The best soils are almost level and are Texture is described in table 11 in standard terms used neither wet nor subject to flooding during the season by the United States Department of Agriculture. These of use. The surface is free of stones or boulders, is firm terms are defined according to percentages of sand, after rain, and is not dusty when dry. If shaping is silt, and clay in soil material that is less than 2 required to obtain a uniform grade, the depth of

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

millimeters in diameter. "Loam," for example, is soil the borderline between two classes have a dual classi- material that is 7 to 27 percent clay, 28 to 50 percent fication symbol, for example CL-ML. silt, and less than 52 percent sand. If a soil contains The AASHTO system classifies soils according to gravel or other particles coarser than sand, an ap- those properties that affect their use in highway con- propriate modifier is added, for example, "gravelly loam." struction and maintenance. In this system a mineral Other texture terms used by USDA are defined in the soil is classified as one of seven basic groups ranging Glossary. from A-1 through A-7 on the basis of grain-size dis- The two systems commonly used in classifying soils tribution, liquid limit, and plasticity index. Soils in for engineering use are the Unified soil classification group A-1 are coarse grained and low in content of system (2, 5) and the American Association of State fines. At the other extreme, in group A-7, are fine Highway and Transportation Officials (AASHTO) (1, grained soils. Highly organic soils are classified as A-8 5) soil classification system. In table 11 soils in the on the basis of visual inspection. survey area are classified according to both systems. When laboratory data are available, the A-1, A-2, The Unified system classifies soils according to prop- and A-7 groups are further classified as follows A-1- erties that affect their use as construction material. a, A-1-b, A-2-4, A-2-5, A-2-6, A-2-7, A-7-5, and A- Soils are classified according to grain-size distribution of 7-6. As an additional refinement, the desirability of the fraction less than 3 inches in diameter, plasticity soils as subgrade material can be indicated by a group index, liquid limit, and the organic-matter content. index number. These numbers range from 0 for the best Soils are grouped into 15 classes-eight classes of subgrade material to 20 or more for the poorest. The coarse grained soils, identified as GW, GP, GM, GC, estimated classification, without group index numbers, is SW, SP, SM, and SC; six classes of fine grained soils, given in table 11. identified as ML, CL, OL, MH, CH, and OH; and one class Also in table 11 the percentage, by weight, of cobbles, or of highly organic soils, identified as Pt. Soils on the rock fragments more than 3 inches in diameter, are estimated for each major horizon. These estimates is largely affected by the quality of the irrigation water are determined largely by observing volume percentage in and the irrigation practices. Hence, the salinity of the field and then converting it, by formula, to weight individual fields can differ greatly from the value given percentage. in table 12. Salinity affects the suitability of a soil for Percentage of the soil material less than 3 inches in crop production, its stability when used as a diameter that passes each of four standard sieves is construction material, and its potential to corrode estimated for each major horizon. The estimates are metal and concrete. based on tests of soils that were sampled in the survey Shrink-swell potential depends mainly on the amount area and in nearby areas and on field estimates from and kind of clay in the soil. Laboratory measurements many borings made during the survey. of the swelling of undisturbed clods were made for Liquid limit and plasticity index indicate the effect of many soils. For others it was estimated on the basis of water on the strength and consistency of soil. These the kind of clay and on measurements of similar soils. indexes are used in both the Unified and the AASHTO soil Size of imposed loadings and the magnitude of changes classification systems. They are also used as indicators in in soil moisture content are also important factors making general predictions of soil behavior. that influence swelling of soils. Shrinking and Range in liquid limit and plasticity index are esti- swelling of some soils can cause damage to building mated on the basis of test data from the survey area or foundations, basement walls, roads, and other structures from nearby areas and on observations of the many soil unless special designs are used. A high shrink-swell borings made during the survey. potential indicates that special design and added expense may be required if the planned use of the soil Physical and Chemical Properties will not tolerate large volume changes. Risk of corrosion, as used in table 12, pertains to Table 12 shows estimated values for several soil potential soil-induced chemical action that dissolves or characteristics and features that affect behavior of soils weakens uncoated steel or concrete. The rate of corro- in engineering uses. These estimates are given for each sion of uncoated steel is related to soil moisture, major horizon, at the depths indicated, in the particle-size distribution, total acidity, and electrical representative profile of each soil. The estimates are conductivity of the soil material. The rating of soils for based on field observations and on test data for these corrosivity to concrete is based mainly on the sulfate and similar soils. content, soil texture, and acidity. Protective measures for Permeability is estimated on the basis of known re- steel or more resistant concrete help to avoid or lationships between the soil characteristics observed in minimize damage resulting from the corrosion. Instal- the field-particularly soil structure, porosity, and lations of steel that intersect soil boundaries or soil gradation of texture-that influence the downward horizons are more susceptible to corrosion than instal- movement of water in the soil. Estimates are for water lations entirely within one kind of soil or within one movement in a vertical direction when the soil is satu- soil horizon. rated. Not considered in the estimates are lateral Erosion factors are used to predict the erodibility of a seepage or such transient soil features as plowpans soil and its tolerance to erosion in relation to specific and surface crusts. Permeability of the soil is an im- kinds of land use and treatment. The soil erodibility portant factor to be considered in the planning and factor (K) is a measure of the susceptibility of the soil design of drainage systems, in evaluating the potential to erosion by water. Soils having the highest K values of soils for septic tank systems and other `waste dis- are the most erodible. K values range from 0.10 to 0.64. posal systems, and in many other aspects of land use To estimate annual soil loss per acre, the K value of a and management. soil is modified by factors representing plant cover, Available water capacity is rated on the basis of soil grade and length of slope, management practices, and characteristics that influence the ability of the soil to climate. The soil-loss tolerance factor (T) is the hold water and make it available to plants. Important maximum rate of soil erosion, whether from rainfall or characteristics are content of organic matter, soil tex- soil blowing, that can occur without reducing crop ture, and soil structure. Shallow-rooted plants are not production or environmental quality. The rate is likely to use the available water from the deeper soil expressed in tons of soil loss per acre per year. horizons. Available water capacity is an important factor Wind erodibility groups are made up of soils that in the choice of plants or crops to be grown and in the have similar properties that affect their resistance to design of irrigation systems. soil blowing if cultivated. The groups are used to pre- Soil reaction is expressed as range in pH values. The dict the susceptibility of soil to blowing and the range of pH of each major horizon is based on many amount of soil lost as a result of blowing. Soils are field checks. For many soils, the values have been verified grouped according to the following distinctions by laboratory analyses. Soil reaction is important in 1. Sands, coarse sands, fine sands, and very fine selecting the crops and ornamental or other plants to be sands. These soils are extremely erodible, so vegetation grown, in evaluating soil amendments for fertility and is difficult to establish. They are generally not suitable for stabilization, and in evaluating the corrosivity of soils. crops. Salinity is expressed as the electrical conductivity of 2. Loamy sands, loamy fine sands, and loamy very the saturation extract, in millimhos per centimeter at fine sands. These soils are very highly erodible, but 25° C. Estimates are based on field and laboratory crops can be grown if intensive measures to control soil measurements at representative sites of the blowing are used. nonirrigated soils. The salinity of individual irrigated 3. Sandy loams, coarse sandy loams, fine sandy fields loams, and very fine sandy loams. These soils are highly

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

erodible, but crops can be grown if intensive measures to information is helpful in planning land uses and engi- control soil blowing are used. neering projects that are likely to be affected by the 4L. Calcareous loamy soils that are less than 35 per- amount of runoff from watersheds, by flooding and a cent clay and more than 5 percent finely divided calcium seasonal high water table, by the presence of bedrock or a carbonate. These soils are erodible, but crops can be cemented pan in the upper 5 or 6 feet of the soil, or by grown if intensive measures to control soil blowing are frost action. used. Flooding is rated in general terms that describe the 4. Clays, silty clays, clay loams, and silty clay loamy frequency, duration, and period of the year when that are more than 35 percent clay. These soils are flooding is most likely. The ratings are based on evi- moderately erodible, but crops can be grown if mea- dences in the soil profile of the effects of flooding, sures to control soil blowing are used. namely thin strata of gravel, sand, silt, or in places, 5. Loamy soils that are less than 18 percent clay and clay deposited by floodwater; irregular decrease in less than 5 percent finely divided calcium carbonate and organic-matter content with increasing depth; absence sandy clay loamy and sandy clays that are less than 5 of distinctive soil horizons that form in soils of the area percent finely divided calcium carbonate. These soils are that are not subject to flooding; local information about slightly erodible, but crops can be grown if measures floodwater heights and the extent of flooding; and to control soil blowing are used. local knowledge that relates the unique landscape position 6. Loamy soils that are 18 to 35 percent clay and less of each soil to historic floods. than 5 percent finely divided calcium carbonate, ex- The generalized description of flood hazards is of value cept silty clay loams. These soils are very slightly in land use planning and provides a valid basis for erodible, and crops can easily be grown. land use restrictions. The soil data are less specific, 7. Silty clay loams that are less than 35 percent clay however, than those provided by detailed engineering and less then 5 percent finely divided calcium carbonate. surveys that delineate flood-prone areas at specific These soils are very slightly erodible, and crops can flood frequency levels. easily be grown. A high water table is the highest level of a saturated 8. Stony or gravelly soils and other soils not subject zone more than 6 inches thick in soils for a continuous to soil blowing. period of more than 2 weeks during most years. The depth to high water table applies to undrained soils. Soil and Water Features Estimates are based mainly on the relationship be- tween grayish colors or mottles in the soil and the Features that relate to runoff or infiltration of water, depth to free water observed during the course of the to flooding, to grading and excavation, and to frost soil survey. Indicated are the depth to the high water action of each soil are indicated in table 13. This table ; the kind of water table, whether perched,

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artesian, or the upper part of the ground water table; which causes the formation of ice lenses. Soil texture, and the months of the year that the high water com- temperature, moisture content, porosity, permeability, and monly is present. Only those saturated zones above a content of organic matter are the most important soil depth of 5 or 6 feet are indicated. properties that affect frost action. It is assumed that the Information about the high water table helps in soil is not covered by insulating vegetation or snow and assessing the need for specially designed foundations, is not artificially drained. Silty and clayey soils that the need for specific kinds of drainage systems, and have a high water table in winter are the most the need for footing drains to insure dry basements. susceptible to frost action. Well drained, very gravelly Such information is also needed to decide whether or not or sandy soils are the least susceptible. to construct basements and to determine how septic tank absorption fields and other underground installations Formation of the Soils will function. Also, a high water table affects ease of excavation. Soils are the products of soil-forming processes Depth to bedrock is shown for all soils that are acting upon material deposited or accumulated by underlain by bedrock at a depth of 5 or 6 feet or less. geologic agencies. The five factors that affect the for- For many soils, limited range in depth to bedrock is a mation of soils are parent material, relief, climate, part of the definition of the soil series. The depths living organisms, and time. shown are based on measurements made in many soil borings and other observations during the soil map- Parent Material ping. The kind of bedrock and its relative hardness as related to ease of excavation is also shown. Rippable Soils in Whitman County formed in loess, volcanic ash, bedrock can be excavated with a single-tooth ripping stream alluvium, glacial outwash, and colluvium and attachment on a 200 horsepower tractor, but hard bedrock residuum from basalt and metasediments. Many generally requires blasting. differences in the soils are directly related to differ- Cemented pans are hard subsurface layers that are ences in parent material. Most of the soils are strongly compacted (indurated). Such pans cause polygenetic in origin, however, and differences in prop- difficulty in excavation. Hardness of pans is defined erties and horizons are related in part to geomorphic the same as hardness of bedrock. history. Potential frost action refers to the likelihood of By HERMAN R. GENTRY. Based on his dissertation "Geomorphology of damage to pavements and other structures by frost Some Selected Soil Landscapes in Whitman County, Washington," Washington heaving and low soil strength after thawing. Frost State University, 1974. Assisting in the preparation of the dissertation were action is defined as freezing temperatures in the soil Warren A. Starr, Dr. Roald Fryxell, and Dr. Henry W. Smith. and movement of soil moisture into the freezing zone,

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Relief and dry conditions cause cracks, also aiding eluviation Most of the county is characterized by rolling loessal of clays. hills. Structure controls direction and gradient of Summers are hot and dry in Whitman County, and westward flowing perennial streams. Streams that have winters are cool and moist. The period in which bio- incised the basalt plateau now meander through the logical and chemical activity is operational depends on loessal hills. The western part of the county consists of the length of time the soil is moist under favorable a network of channels known as "channeled temperatures. Since most of the soils are dry or nearly scablands." A few buttes of metasediments that pro- dry during the warm months, they frequently are not trude through the basalt plateau are in the eastern moist when the favorable temperatures prevail. The part of the county. Along the northern margin are moisture regime depends on the effectiveness and timing deep basaltic canyons referred to locally as the "Snake of precipitation ; also, it is influenced by soil char- River Breaks." Elevation ranges from about 0-00 feet in acteristics. Temperature is a measure of heat that is the southwestern part of the county along the Snake River available for chemical, physical, and biological reac- to 4,000 feet above sea level in the eastern part. tions involved in soil formation. If water is not a limiting factor, the rate of mineral weathering in- Climate creases with the temperature. Higher temperatures also hasten decomposition of organic matter by oxidation, Climate is an active factor in soil formation. The and content of organic matter, consequently, is lower. primary climatic factors in soil formation are tem- perature and precipitation. Climate affects soil formation Past climatic conditions by its influence on weathering, organic matter production, and decomposition, leaching, erosion, and Past climatic conditions in the county, especially vegetation. It influences the kind and the density of the during the Pleistocene, alternately favored soil forma- plants that grow in an area. tion and soil truncation or burial. Soil profiles formed Annual precipitation ranges from about 11 inches in during periods when sedimentation or erosion proceeded the southwestern part of the county to 23 inches in the slowly and soil forming processes were active for a northeastern part. Snow provides most of the winter significant length of time. Glacial intervals were per- precipitation. Rain and warm winds often melt the snow iods of soil truncation or burial, and interglacial rapidly resulting in loss of moisture by runoff, intervals of the Pleistocene were periods of soil forma- especially if the soil is frozen near the surface. Usually tion. Paleosols are often truncated down to resistant more water is lost as the slope increases and less water caps of caliche or B horizons that are rich in clay. is available for weathering and leaching of the soil. Relict soil features reflect former moisture regimes. The kind and degree of eluviation depends on the Former periods of freezing climates resulted in frost amount of water percolating through the soil under sorting and solifluction. Solifluction occurs when the present and past climatic conditions. This is reflected by ground is frozen part of the year, forming interstitial the characteristics of the soils in this area. Percolation ice and lenses of ice, so that on thawing soils settle is influenced by the amount of precipitation and with a resultant downslope displacement. Some soils evapotranspiration and by the length of the frost-free such as those of the Alpowa series on the side slopes period. High evapotranspiration impedes leaching and in of major drainageways, have stone lines that may be places causes upward movement of soluble salts. related to periods of erosion and deposition during Frequent rainstorms that produce turbulent movement solifluctional movements. Intense frost action during of water (saturated flow) through large pores and periglacial climate was a significant factor in the cracks aid in eluviation of clays. Alternating wet formation of patterned ground in central Washington. Mounds (biscuits) formed where a previous soil

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mantle was less than 6 feet deep and conditions be- layers called horizons are formed. Some of the soils came favorable for formation of ice-wedge polygons. have been in place long enough to have formed strongly Mounds are in channeled scablands on outwash ter- expressed horizons; others are unaltered or only races and in areas where basalt is very shallow to deep. slightly altered parent material. The length of time Soils that formed under prairie vegetation generally required for a soil to develop depends on the nature of have a dark, friable surface layer high in content of the parent material and the modifying effect of the other organic matter and are saturated with bases (more soil-forming factors. than 50 percent). Some soils that occur at high eleva- tions on north- and northeast-facing side slopes, such as Parent Material Origin and Age Relationship Tekoa gravelly silt loam, deep, have these character- istics but are now supporting coniferous forest. This The oldest geologic materials in Whitman County indicates that perhaps some prairie areas in Whitman from which soils have formed are Precambrian meta- County have been invaded by coniferous forests. sediments of the Belt Supergroup. The metasediments consist of quartzite, schists, gneisses, and related rocks. Living Organisms These sediments were subjected to metamorphism, injections of pegmatite by granitic intrusions, and Living organisms are active in the formation of soils. folding. Major exposures of granitic rock in Whitman Plants, micro-organisms, earthworms, man, and other County are Bald Butte and Granite Point. The forms of life are important in determining the rate and metasediments were uplifted and dissected to form a direction of soil formation. mountainous terrain. During the early Tertiary period The kinds of plants and animals present largely de- deep weathering of metasediments and exposed termine the kinds and amount of organic matter added granodiorite occurred under a subtropical or tropical to the soil and how this matter is incorporated with the climate. Residual clay deposits more than 100 feet mineral part of the soil. thick were formed in places. A remnant of this When the first settlers arrived in Whitman County, strongly oxidized profile is on Kamiak Butte. the vegetation was predominantly bunchgrasses mainly During Miocene-Pliocene time, many extensive lava bluebunch wheatgrass and Idaho fescue. Open stands of flows extruded through fissures. Whitman County was conifers, mainly ponderosa pine, are in small areas along covered, except for some of the highest hills of drainageways and in the northeastern part of the county. metasedimentary rock. The lava flows caused disruption The understory in these areas is grass and shrubs. of drainages resulting in slackwater clay deposits, which Coniferous forests, mainly Douglas-fir, are on some of are called the Latah Formation. The weight of the lava the buttes. caused the Columbia Plateau basalt to tilt downward Man has drastically altered soils, especially the upper toward the Pasco Basin. layers, by plowing and farming grassland and by Basalt is exposed mainly on side slopes of major clearing wooded areas. The decrease in content of drainageways and in channeled scablands. Most loess organic matter and the acceleration of erosion in most of basalt contacts are quite abrupt, suggesting that some the steeper cultivated soils are evidences of man's erosion of previously weathered basalt took place prior to influence. the deposition of the loess. In places residual soils have formed in weathered basalt. Some soils on valley and Time canyon sides in Whitman County have older B horizons that contain rounded basalt fragments and some soft Time, as a soil forming factor, begins as soon as rock is weathered basalt fragments. Elsewhere, older B exposed on the surface or a fresh mantle of loess is laid horizons contain basalt fragments with sharp edges that down. As soil formation progresses, characteristic indicate less weathering. The oldest B ho-

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rizons probably have been destroyed by frost churning or moved parallel to the ground surface at no greater solifluction. height than a few yards, while the turbulent action of The complex origin of the loess in terms of multiple wind results in others being carried high above and processes has been postulated. Local ponding, streams, and horizontal to the ground for many miles. The gradual sheet wash play a secondary role in loess deposition. decrease in the carrying capacity of the wind with Studies that tied the Palouse loess to the Ringold increasing distance from the source of loess would account Formation have been made. Most of the Ringold For- for the particle size decrease. Since deposition, different mation is believed to postdate the broad folding and rates of weathering caused by differences in precipitation dissection of the Columbia Plateau in Pliocene time, have influenced particle size. This is reflected by the though in the deeper parts of the basins it may contain increase in clay fraction in the wetter environments. some sediments contemporaneous with downwarping. This The cumulative loess thickness exceeds 250 feet in the formation is considered to be the major source of loess south-central part of Whitman County and is about 80 deposits older than the channeled scablands, but other feet in the northeastern corner. sources of loess have been involved for areas not The approximate ages and some of the important downwind from any known deposits of Ringold. properties of the various loess deposits in Whitman Undoubtedly some loess was blown southward from County are as follows: the Cordilleran Ice Sheet as a periglacial phenomenon. Some post-scabland loess was derived from the lacustrine Post-Pinedale.-Less than 6,700 years old. Horizon Touchet Beds, and probably some was derived from development is minimal. alluvium along the Snake and Columbia Rivers. Pinedale.-6,700 to 25,000 years old. Generally, profiles Particle size of loess tends to decrease toward the are 18 inches to 3 feet thick, have moderate more elevated parts of the Palouse Hills with increased structural grade, and have a slight increase of clay in distance from the source of loess. Some particles are the B horizon.

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Bull Lake.-25,000 to 50,000 years old. Generally, B horizons or were deposited on top of them in the profiles are 3 to 10 feet thick. Where annual precip- more arid regions. The loess deposits have extremes of itation is less than 18 inches, chalky white Cca salt and carbonate accumulation in the drier areas but horizons are present. Where annual precipitation is low salt and carbonate content when followed east- more than 18 inches, argillic horizons having strong ward to progressively wetter areas. The B horizons in structural grade are present. the drier areas contain little clay, and those in the Pre-Bull Lake.-More than 50,000 years old. Gen- eastward wetter areas are rich in clay. This indicates erally, profiles are more than 10 feet thick. Where that the wettest areas during past climatic fluctuations annual precipitation is less than 18 inches, indurated are still the wettest and the driest areas are still the siliceous caliche, hard manganese dioxide concretions, driest, even though the precipitation might have been and pink Cca and Ccasim horizons are present. greater or less in the past than it is now. Remnants of platy caliche persist even where B Concentrations of calcium carbonate (caliche) were horizons are missing. Where annual precipitation is formed during interglacial intervals of the dry phase. At more than 18 inches, strongly developed, highly those times leaching was minimized, and water and oxidized (7.5YR and 10YR hues) argillic horizons dissolved salts were drawn upward by capillary action. containing hard manganese dioxide concretions are Thus, loss of much water by evaporation into the air present. occurred, and concentrations of calcium carbonate re- mained. The major calcium carbonate accumulations in The soils in Pre-Bull Lake and Bull Lake loess de- Whitman County appear to result from a combination of posits have formed B horizons that have well expressed precipitation, eolian sources, and pedogenic processes. structure. These horizons formed during the early The floods of glacial meltwater that eroded the portion of interglacial periods when both adequate pre- channeled scablands left a remarkable network of cipitation and relative warmth prevailed. Drier periods channels with erosional and depositional features un- followed, and carbonates engulfed the pre-existing

gested : the accumulation of snow along with some soil like those of normal stream valleys. Gravel and sand on the upper part of the slopes and erosion at the toe of deposits are also on the foot slopes of the Snake River the snowdrifts. Sharpening of the steep north slopes breaks in Whitman County. The upper limit of deposits occurred during Pinedale time, and present erosion is from slack water off the Snake River is considered to aggravated by slumping of the Post-Pinedale loess, be 1,200 feet above sea level. which contains considerable amounts of volcanic ash Pinedale and Post-Pinedale loess deposits are draped and is underlain by a slowly permeable B horizon. The over all earlier deposits. Middle Pinedale and Post- southwest and northeast alinement of topography in the Pinedale loess deposits also occur on parts of the western part of Whitman County undoubtedly was caused channeled scablands and thus locally are more extensive by strong prevailing winds from the southwest. though thinner than earlier loess deposits. Mounds in the Alinement of hills results from loess whose median channeled scablands contain remnants of both of these grain size exceeds 0.0270-0.0280 mm. High wind loess deposits. The B horizons in Middle Pinedale loess velocity is required to carry these relatively coarse are truncated by Post-Pinedale loess at the outer edges particles. The finer fraction of loess would be deposited of the mounds. only when winds reached a lower velocity. Low velocity Amphiboles (hornblende) are the dominant heavy winds are considerably more variable in direction, so minerals in the loess deposits in Whitman County. the areas with finer fractions of loess do not possess the Epidote, opaques, hypersthene, pyroxenes, and other linear topography. Possibly the landforms were the heavy minerals are present in lesser amounts. Quartz, products of both erosional and depositional processes, feldspar, and mica are the dominant light minerals, and erosion was dominant in the wetter eastern areas and volcanic glass is present in varying amounts. while deposition was dominant in the drier western Pinedale and Altithermal and Post-Altithermal loess areas where linear topography has been recognized. The deposits contain more volcanic glass than earlier loess, wetter eastern part of Whitman County has asymmetrical and some are more than 30 percent volcanic glass. The hills and more complex landforms than the drier western mineral composition indicates that these sediments are part. The landforms in the eastern part are the products transported, because they contain significant amounts of a combination of erosional and depositional of quartz and potassium feldspar not found in the processes under the influence of vegetative differences. locally weathered basalt. Weathered basalt has Thick loess deposits have accumulated on the leeward considerable amounts of calcic plagioclase and pyroxene side of bedrock ridges. In general each deposit phenocrysts in the very fine sand fraction. progressively overlaps previous surfaces, so that each Along streams and in basins the main parent mate- deposit over a preexisting surface is thicker on rial is alluvium derived primarily from loess. Some northeasterly slopes, which results in a shift sections may contain sandy lenses or ash layers, how- northeasterly in drainage divides. Loess also ever, or may be a mixture of loess with metasedimen- accumulated in hollows between snowdrifts during tary material or basalt. Mount Mazama volcanic ash winter months. (6,700 years old) has been identified in two layers of Tillage erosion has accelerated the natural process of Caldwell silt loam, drained-one at 59 to 69 inches shaping the landscape. Both water erosion and tillage and another at 69 to 80 inches. Hence, for this profile, erosion are prevalent in Whitman County. They are alluvium above 59 inches is Post-Pinedale, and its affected by climate, the soil itself, and soil treatment or accumulation postdates the development of large other management. Earth flows occurred above the B'2t meandering Pinedale streams. Volcanic ash layers soil horizon on northerly slopes and were a very were found at only one site of Caldwell silt loam, important factor in the shaping of the hills. drained. Such layers (probably layers of Mount Major streams such as the Palouse River have main- Mazama volcanic ash) occur in many places in Covello and tained their preloess drainageways. Loess deposits are Hermiston soil profiles. Apparently most of the draped down into some of the drainage channels. Modern alluvium is Post-Pinedale, with clay-rich B horizons and first and second order drainageways are independent of some C horizons of Pinedale alluvium. bedrock configuration and are usually cut in loess only. High, steep hills in the St. John and Wilcox areas have Topographic and Structural Control resulted from greater stream entrenchment brought about by steeper stream gradients. These gradients were The origin of the topography in Whitman County caused by inclination of the basalts and the thicker has been the subject of several studies. Some have loess deposits. Areas with thin loess deposits on a suggested that the primary topographic features were rather smooth and flat basalt surface have hills of low produced by erosion and not by deposition, and that relief. the hills resembled sand dunes with amphitheaterlike In the eastern part of the county, three micro- enclosures on the northern sides. Others have theorized climates have been considered in previous studies in that the dunelike shape of these hills was the result areas with convex narrow ridgecrests. The north- and of late summer winds shifting dry soil from the northeast-facing side slopes were more moist where southwest slopes to the lee side of the hills. Some have snow accumulated in drifts and melted slowly. The more suggested that drainage patterns are not a normal exposed ridgecrests were the driest, and other areas dendritic pattern but that cirquelike amphitheaters result were considered to be intermediate in amount of from accumulation of deep snowdrifts on the north and effective precipitation. Some soils are characterized by east slopes resulting in nivation and slumping. A an excess of moisture because of profile combination of two processes has been sug- characteristics that restrict water percolation or be-

cause the soil is in a low area. These differences in acids. Thus, as precipitation increases there is more moisture are expressed in differences in degree of soil organic matter, vegetation, and downward movement of development and type of vegetation present. water, resulting in more intense and deeper leaching of Generally as elevation increases, precipitation in- soils. Reaction in Ritzville soils is neutral to mildly creases and temperature decreases. Thus, there is more alkaline in the A horizon, neutral or mildly alkaline in the total plant growth and slower decomposition of organic B horizon, and moderately alkaline or strongly alkaline in materials at higher elevations in the eastern part of the C horizon. Reaction in Walla Walls soils is neutral in Whitman County than there is at lower elevations in the A horizon, neutral or mildly alkaline in the B the western part. horizon, and mildly to strongly alkaline in the C Soils with minimal profile development can be ob- horizon. Reaction in Athena soils is slightly acid to neutral served on steep side slopes of major drainageways and in the A horizon, neutral to mildly alkaline in the B in places on buttes. In these areas, rate of soil develop- horizon, and mildly alkaline to strongly alkaline in the ment is equal to or exceeded by removal of surface C horizon. Reaction in Palouse soils is medium acid soil by erosion or disturbance by mass movement. to neutral in the A horizon and slightly acid to neutral Solifluction was probably a potent agent in mass move- in the B horizon. Palouse soils do not have a C horizon ment during former freezing periods. Even where within a depth of 60 inches. steep soils have excellent vegetative cover, gravity can Precipitation can also affect base saturation. Higher cause slow mass movement downslope, thus reducing the precipitation is usually associated with greater leaching, effects of soil formation. which results in lower base saturation. Palouse soils, in a higher precipitation area, have the lowest base Characteristics of Dominant Soils saturation percentage and the highest organic matter percentage. Ritzville soils have the highest base The degree of horizon differentiation in dominant soils saturation-79 to 100 percent in the A horizons, 82 to that formed mainly in Pinedale and Post-Pinedale loess 100 percent in the B horizons, and 85 to 100 percent deposits increases from the west to east. The soils in this in the C horizons. Base saturation of Walla Walla soils sequence are in the Ritzville, Walla Walla, Athena, is 69 to 89 percent in the A horizon, 78 to 90 percent in and Palouse series. the B horizons, and 93 to 100 percent in the C horizon. Base saturation of Athena soils is 68 to 92 percent in Organic matter the A horizon, 77 to 85 percent in the B horizon, and 86 to 100 percent in the C horizon. Base saturation of Thickness of mollic epipedons and content of organic Palouse soils is 65 to 71 percent in the A horizon, (up matter increase with increased rainfall. The mollic to 77 percent in the A3 horizon) and 68 to 87 percent epipedon of Ritzville soils ranges from 8 to 14 inches in the B horizon. Presently the Palouse soils are thick. The organic matter content of the dark brown A considered to have an average base saturation of less horizon is 1 to 1.3 percent. The mollic epipedon of than 75 percent in the upper 30 inches. Walla Walla soils ranges from 10 to 18 inches thick. The organic matter content of the very dark brown All horizon is 1.3 to 2.2 percent, and that of the very Calcium carbonate dark grayish brown A12 horizon is 1.0 to 1.7 percent. The mollic epipedon of Athena soils ranges from 20 to The calcium carbonate (lime) layer is variable in the 30 inches thick. The organic matter content of the Ritzville, Walla Walla, Athena, and Palouse soils. very dark brown Ap horizon is 1.6 to 3 percent, and Ritzville soils are defined as having segregated lime in that of the very dark brown A12 horizon and very pores and root channels at depths of 30 to 43 inches. Many dark grayish brown A13 horizon is 1.5 to 2.7 percent. Ritzville pedons in this area have a highly calcareous, The upper part of the B horizon with its dark brown noncemented, relict calcium carbonate horizon below the colors and 1.0 to 1.5 percent organic matter still meets segregated lime. the requirements of a mollic epipedon. The mollic Walla Walla soils on most ridgetops have lime at a epipedon on the Palouse soils ranges from 20 to 36 depth of 43 to 60 inches or more, but on other slopes in inches thick. The organic matter content of the very Whitman County lime is mostly below a depth of 60 dark brown Ap horizon is 2.6 to 4.2 percent. The or- inches. The lime layer in some Walla Walla soils is ganic matter content of the very dark brown Al hori- weakly cemented, has an abrupt boundary, and usually zon is 2 to 3.3 percent. The organic matter content of reflects a relict Cca horizon. In some Walla Walls soils, the very dark grayish brown A3 or dark brown B1 however, accumulation of lime occurs above the relict Cca horizon is 1.0 to 2.7 percent. horizon. Athena soils on most ridgetops and southerly facing Soil reaction and base saturation slopes have lime at a depth of 43 to more than 60 Reaction tends to decrease as precipitation increases. inches. The lime is at a depth below 60 inches in most Ritzville soils formed under 9 to 12 inches of annual Athena soils with west-, east-, and north-facing slopes. precipitation and have the highest reaction; Palouse The depth to lime in these Athena soils is possibly the soils formed under 18 to 24 inches of annual result of thicker loess deposits, more moisture, and deeper precipitation have the lowest reaction. Decomposition of leaching. The abrupt boundary to the Cca horizon suggests organic matter produces both organic and inorganic the presence of a relict lime horizon. Generally Athena soils adjacent to the Athena-Palouse transitional zone either lack lime horizons or have weakly defined ones. In some areas of broad flat slopes adjacent to major drainages, however, layers with large younger ones. Field identification of weathering profiles amounts of lime are present. can be made by comparisons of profile thickness, depth Palouse soils are free of lime accumulations. When of clay enrichment, and amount of oxidation under comparing soils arranged in the order of increasing similar conditions. precipitation, there is an increase in the degree of The topography in Whitman County contains many leaching of lime, but the depth of the relict Cca hori- facies of different ages. These have been exposed to zons appears to be related more to the thickness of soil forming processes under markedly different cli- Pinedale and Post-Pinedale loess depositions than to the matic conditions and for different lengths of time. degree of leaching. Ritzville, Walla Walla, Athena, and Palouse soils have B horizons that formed in Pinedale loess. These soils Development of B Horizons have A horizons that formed in Post-Pinedale loess, but in places they have older loess in the lower part of the With increasing soil formation and horizon expres- profile. In places the B3 horizons of Palouse soils appear to sion, B horizons usually exhibit a more oxidized have formed in Bull Lake loess. In some areas these (redder) color, have a higher percentage of clay, have soils are interspersed with soils that have more stronger grades of structure, and are thicker. The B advanced morphological soil characteristics, primarily horizons in Ritzville soils have a value of 3 or 4 moist because of their function on soil landscapes of greater and 4 or 5 dry and a chroma of 3 or 4 either moist or age. dry. Ritzville soils are silt loams that are 6 to 12 per- The drier, western part of Whitman County has cent clay. They. have weak, coarse or medium, pris- linear hills. Walla Walla soils are dominant in this matic structure, and they extend to a depth of 20 to 38 part of the county. Small areas of Ritzville soils are in inches. the southwestern part of this area. Areas of Walla The B horizons in Walla Walla soils have a value of 3 Walla soils are interspersed with small areas of Endi- or 4 moist and 5 or 6 dry. Chroma is 3 moist or dry. cott and Risbeck soils. Walla Walla soils are silt loams that are 11 to 18 per- Endicott and Risbeck soils are in parts of the land- cent clay. They have weak, medium or coarse, pris- scape where Pinedale and Post-Pinedale loesses are matic structure, and they extend to a depth of 31 to 52 thinner. Endicott soils have 20 to 40 inches of Pinedale inches. and Post-Pinedale loess deposits over Pre-Bull Lake The B horizons in Athena soils have a value of 3 or 4 and Bull Lake loess deposits that contain a lime-silica moist and 5 or 6 dry. Chroma is 3 or 4 moist or dry. cemented hardpan. Pre-Bull Lake loess deposits char- Walla Walla soils are silt barns that are 18 to 25 per- acteristically have more strongly cemented lime hori- cent clay. They have weak or moderate, medium or zons than Bull Lake loess. Consequently, variability in coarse, prismatic structure, and they extend to a depth of lime cementation depends on which loess unit is 43 to 59 inches. present. Endicott soils are on ridgetops and low-lying The B horizons in Athena soils have organic coatings on broad benches. It appears that on the low-lying broad ped faces in the upper part, and some have incipient benches along edges of channeled scablands, flood- bleaching expressed as gray siliceous coatings on ped waters may have stripped away part of the Pre-Bull faces in the intermediate part. Lake and Bull Lake loess deposits down to the resistant The B horizons in Palouse soils have a value of 3 or 4 lime-silica cemented hardpans. Risbeck soils are on the moist and 5 or 6 dry. Chroma is 3 or 4 moist or dry. side slopes and ridges where calcareous Pre-Bull Lake Palouse soils are silt loams or light silty clay loams and Bull Lake loesses are exposed. They formed in that are 20 to 30 percent clay. They have weak or calcareous loess consisting of alternating layers of lime moderate, medium or coarse, prismatic structure, and hardpan and loose limey silt of variable thickness and in they extend to a depth greater than 60 inches. The B colluvium from this material intermixed with some horizons have a few thin clay films and organic coat- Pinedale and Post-Pinedale loess. ings on ped faces. Some have incipient bleaching The wetter, eastern part of Whitman County has expressed as gray siliceous coatings on ped faces. These asymmetrical hills. Athena soils are dominant in the siliceous coatings become more apparent on north ex- western and southern parts of this area. They are posures and in the northeastern part of Whitman interspersed with small areas of Lance and Calouse County. soils. Palouse soils are dominant in the eastern part. They are interspersed with Thatuna, Naff, Garfield, Relationship of Modern and Relict Landscapes to Staley, and Tilma soils. Present Distribution of Soils Lance and Calouse soils are in parts of the landscape where Pinedale and Post-Pinedale loess deposits are Most soils in Whitman County have superimposed thin. Lance soils are on side slopes and ridgetops profiles, the result of the development of young weathering where calcareous Pre-Bull Lake and Bull Lake loess profiles on older and deeper ones. Superimposed profiles deposits are exposed. They formed in calcareous loess of different ages may be suggested by such discontinuities consisting of alternating layers of cemented caliche and in the soil profile as abrupt change in texture, color, loose limey silts of variable thickness and in colluvium alkalinity, or acidity; or, in alkaline areas, by of this material intermixed with some Pinedale and Post- repetition of lime-free layers beneath lime-enriched Pinedale loesses. Calouse soils have 20 to 40 inches of layers. But the compelling evidence that a soil consists Pinedale and Post-Pinedale loess deposits over Pre-Bull of two or more weathering profiles must be sought by Lake and Bull Lake noncemented calcareous loess tracing the weathered layers laterally to a place where deposits. The characteristics of Cca horizons depend on the older layers become separated from the base of the which of the earlier loess deposits

B horizon appears as the present A3 horizon of Thatuna is present and on the influence of recent environmental soils. conditions. The Calouse soils are on the side slopes and In northeastern Whitman County Thatuna soils have B2 ridgetops. horizons above the A'2 horizon. Stratigraphically it Naff and Garfield soils formed on low-lying old appears that Thatuna soils with an A1, A3, A'2, and surfaces of the landscapes that have been reexposed B'2t horizon sequence are in parts of the landscape that for soil forming processes to again be activated. Naff have been subjected to nivation and slumping and the and Garfield soils have strongly oxidized and clayey B resulting removal of B2 horizons. These B2 horizons are horizons. It appears that their B horizons formed probably Pinedale loess, and the A1 horizons are Post- during the Pleistocene epoch when the geomorphic Pinedale loess. The A'2 horizon for Thatuna soils with surface was stable for a long period. The B horizons of A1, B2, A'2, and B2t horizon sequence may be a these soils are considered to be largely relict, but degraded A1 horizon. The degradation of former A1 silicate clay presently is accumulating in the upper horizons to horizons similar to A'2 horizons has been parts. In some pedons buried portions of the B horizons observed in several road cuts in Whitman County. have degraded. For example, the Naff and Garfield soils Thatuna soils have a thicker than normal dark A formed in more than one Pre-Bull Lake unit. Thus, horizon. During the Post-Pinedale period (xerothermic variation in expression of the B horizons depends on maximum), vegetation was thinner and shorter par- which loess deposit it formed in and the amount of ticularly on west- and south-facing slopes. Strong available moisture induced under differing topographic prevailing winds from the southwest redeposited the positions. The argillic B horizons of Naff and Garfield soils volcanic veneer from slopes with sparse vegetation to have oriented clay skins and develop vertical cracks the north and northeast slopes on the other side of the about one-fourth to one-half inch wide down to a depth ridge. Redeposition of loess would be unlikely even during of 20 to 30 inches when dry. Naff soils have an A horizon dry periods when vegetation was sparse because of Post-Pinedale loess and in places have an AB or B1 undisturbed surfaces would be protected by cryp- horizon of Pinedale or Bull Lake loess. But Garfield tograms. During part of the Post-Pinedale period probably soils normally occur on ridgetops and knobs where Post- not much loess material was deposited other than Pinedale and Pinedale loess failed to accumulate and the volcanic ash. Also in the Athena-Palouse transitional A horizon developed mainly in Pre-Bull Lake loess. area, thick nearly pure ash layers have been found on It appears that Tilma and Naff soils have the same the north slopes. These ash layers are also in the Walla relict B horizon. In places Tilma soils form on the Walla area on the north and northeast slopes, which lower edges of Naff soils where there is increased indicates that during this period little loess was de- available moisture and some thickening of the Post- posited with volcanic ash. Probably there has been a Pinedale loess. Thus, Tilma soils occur where there is differential vegetative cover in this area during loess more available moisture and have A2 horizons and more deposition which still persists today. The taller and strongly expressed argillic B horizons than Naff. more luxuriant vegetation is confined to the leeward The argillic B horizons of Thatuna soils formed in slopes and to higher areas to the east where precipitation more than one loess deposit. Thus, variation in expression is more effective. The luxuriant vegetation traps and of the horizons depends on which loess deposit they have holds the volcanic-influenced material in those localities. formed in and the amount of available moisture induced Gradual accumulation of volcanic-influenced material may under differing topographic positions. Thatuna soils explain the thick A horizon of the Thatuna soils. formed in Pre-Bull Lake and Bull Lake loess deposits, Fringe areas and areas more distant from the source of and their B horizons contain no ash. This indicates that loess have thinner individual deposits of each age of their argillic B horizons formed in loess older than that loess; thus, older loess deposits are near the surface. of Pinedale age. The argillic B horizons of Thatuna soils Whitman County is in the more central part of the are not as strongly oxidized as the argillic B horizons of loess deposits and has thick loess layers. In some small Naff and Tilma soils, and they probably formed more areas loess layers are thinner, however, or some of recently than those in Naff and Tilma soils. The argillic the loess deposits are absent. These areas are on ridge- horizons of Thatuna soils are considered to be largely tops, southerly side slopes, shoulders, and knobs. In relict, but silicate clay presently is accumulating in other areas thinner layers of loess are on large portions of the upper parts of the horizon. the landscape. The location of the A'2 horizon in Thatuna soils was Reardan soils are mainly on low-lying broad benches established by abrupt changes in compaction and per- along the edges of the channeled scablands. It is pos- meability occurring at the lower boundary of loess tulated that flood water stripped away the soil material modified by volcanic ash. above the resistant B horizons. Gravel has been ob- In areas near the towns of Steptoe, Colfax, and Pull- served on top of the B horizon and between peds of the man, Thatuna soils are on concave and smooth north and upper part of the B2t horizon of Reardan soils. northwest slopes and on foot slopes. Thatuna soils appear Reardan soils have an A1, B&A sequence over the B2t to occur mainly in parts of the landscape that were horizon. sharpened during Pinedale time. In most places they are between convex areas of Palouse soils. Palouse soils on these convex slopes have some bleaching on ped faces in Classification of the Soils the upper part of B horizons. Thatuna soils in these areas have A3 horizons instead of B2 horizons over A'2 The system of soil classification used was adopted by horizons. The weakly formed Post-Pinedale the National Cooperative Soil Survey in 1965.

Readers interested in further details about the system table 14 the soils of the survey area are classified should refer to the latest literature available (7). according to the system. Categories of the system are The system o L' classification has six categories. Be- briefly discussed in the following paragraphs. ginning with the. broadest, these categories are order, ORDER. Ten soil orders are recognized. The prop- suborder, greatgroup, subgroup, family, and series. In erties used to differentiate among orders are those this system the bases for classification are the differ- that reflect the kind and degree of dominant soil- ent soil properties that can be observed in the field or forming processes that have taken place. Each order is those that can be inferred either from other properties that identified by a word ending in sol. An example is Mollisol. are observable in the field or from the combined data of SUBORDER. Each order is divided into suborders soil science and other disciplines. The properties selected based primarily on properties that influence soil genesis for the higher categories are the result of soil genesis or and that are important to plant growth or that of factors that affect soil genesis. In

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

were selected to reflect the most important variables the survey area are under the influence of the prevail- within the orders. The last syllable in the name of a ing westerly winds. Infrequently, dry continental air suborder indicates the order. An example is Xeroll masses enter this region from the north or east. During (Xer, meaning moist in winter and dry in summer, summer, this air from the continent results in low plus oll, from Mollisol.) humidity and high temperatures, while in winter the GREAT GROUP. Each suborder is divided into great weather is clear, cold, and dry. Extreme temperatures groups on the basis of close similarities in kind, ar- in both summer and winter generally occur when the rangement, and degree of expression of pedogenic hori- Inland Basin is under the influence of air from the zons; soil moisture and temperature regimes; and base interior of the continent. Occasional outbreaks of cold, status. The name of a great group ends with the name continental air in spring and fall have caused extensive of a suborder. A prefix added to the name suggests crop damage. Precipitation data for Whitman County are something about the properties of the soil. An example is presented in tables 15 through 18; temperature data Haploxerolls (Hapl, meaning simple horizons, plus xeroll, is presented in these same tables and also in tables 19 the suborder of Mollisols). and 20, table 20 providing probabilities of freezing SUBGROUP. Each great group is divided into three temperatures in spring and in fall. kinds of subgroup: the central (typic) concept of the Summers are warm, dry, and sunny in Whitman great groups, which is not necessarily the most exten- County. Afternoon temperatures in the warmest summer months range from 80° to 90° F and occasionally reach sive subgroup; the intergrades, or transitional forms to ° other orders, suborders, or great groups; and the extra- the upper nineties or 100 . Temperatures drop rapidly after sunset, and nighttime readings range from 45° to grades that have some properties that are representa- ° tive of the great groups but do not indicate transitions 55°. Maximum temperatures have reached 90 or higher to any other known kind of soil. The names of sub- on 40 days in the warmest summers and on less than 10 days during the coolest. The highest temperature groups are derived by placing one or more adjectives ° before the name of the great group. The adjective recorded in the survey area is 113 . The average diurnal range in temperature is about 30° in summer, 10° in Typic is used for the subgroup that is thought to ° ° typify the great group. An example is Typic Haplo- winter, and 15 to 20 in spring and fall. xerolls. Through the warmest months, relative humidity FAMILY. Families are established within a sub- ranges from approximately 60 percent at sunrise to 25 group on the basis of similar physical and chemical percent in midafternoon. In spring and fall, the range properties that affect management. Among the prop- is from 75 percent at sunrise to 5 percent in the erties considered in horizons of major biological ac- afternoon; in winter it is from 90 percent at night to tivity below plow depth are particle-size distribution, 80 percent during the day. mineral content, temperature regime, thickness of the soil In winter, weather systems moving eastward across penetrable by roots, consistence, moisture equivalent, Washington and an occasional system moving south- slope, and permanent cracks. A family name consists ward from Canada result in frequent weather changes. of the name of a subgroup and a series of adjectives. On a typical winter day, the afternoon temperature is The adjectives are the class names for the soil near freezing and the nighttime reading is in the properties used as family differentiae. An example is lower twenties. During an average winter, maximum coarse-silty, mixed, mesic, Typic Haploxerolls. temperatures fail to rise above freezing on about 1 day SERIES. The series consists of a group of soils that in 3 and minimum temperatures drop to zero or lower are formed from a particular kind of parent material and on 3 to 6 nights. In January, generally the coldest month, minimum temperatures can be expected to drop to have horizons that, except for texture of the surface ° soil, are similar in differentiating characteristics and in 0 or lower on 1 or more nights in 1 out of 2 years, - arrangement in the soil profile. Among these 10° in 1 out of 3 years, and -20° F in 1 out of 5 characteristics are color, texture, structure, reaction, years. consistence, and mineralogical and chemical composition. Precipitation is light during summer. It increases in fall, reaches a peak in winter, then decreases in spring, with a slight increase in June and a sharp decline Climate about the first of July. In an average year, thunder- storms occur on 8 to 15 days between March and The climate of Whitman County is influenced to a October. Thunderstorms in midsummer are generally great extent by the prevailing westerly winds and the limited to isolated cells rather than a line of storms Cascade and Rocky Mountain ranges. The Rocky covering a wide area. As a result, crop damage from Mountains shield this section of Washington from the heavy precipitation or hail is generally confined to more severe winter storms that move southward across comparatively small areas. One summer in 10 has a Canada, while the Cascade range forms a barrier to the total rainfall for July and August of less than 0.01 inch. easterly movement of moist air from the Pacific ocean. Likewise, 1 year in 10 has rainfall during these months However, some of the air from each of these source of more than 1 inch. During each month in fall, the regions reaches the Inland Basin and produces a cli- total rainfall can be expected to range from approxi- mate similar to the continental and marine types. mately 1/2 inch to 4 inches in 8 years out of 10. Most of the air masses and weather systems crossing Most of the winter precipitation between mid- December and mid-February is snow. The average By EARL L. PHILLIPS, climatologist for Washington, National Weather annual snowfall ranges from 25 inches in the western Service, U.S. Department of Commerce. part of the survey area to 35 inches in the eastern part.

or rain on a snow cover sometimes results in rapid melting, heavy runoff, severe erosion, and flooding along the larger streams. Generally, precipitation increases in an easterly di- rection across the survey area. Average annual precip- itation ranges from approximately 11 inches in the lower elevations near the western edge of the survey area to 23 inches in the higher elevations near the Idaho border. One year in 10 generally has an annual precipitation of less than 10 inches at the western edge of the survey area. Also, this same area will probably In the original manuscript, there was a receive more than 20 inches of annual precipitation in 1 table in this space. out of 10 years. In the eastern part of the survey area, heavier annual precipitation in the past has ranged from All tables have been updated and are 15 to 28 inches in 8 out of 10 years. available as a separate document. Depth of frost in the soil varies from year to year and is influenced by the snow cover and temperature. Frost in the ground reaches a depth of 10 to 20 inches in a typical winter. In extremely cold winters when there is light snow cover, depth to frost ranges from 25 to 30 inches or more. During winter, moist air that crosses the Cascade Mountains and mixes with the colder air in the Inland Basin results in considerable cloudiness and some fog. Frost collects on highways, trees, utility wires, and other objects. Moderate to heavy fog forms Annual snowfall ranges from less than 5 to more than 50 on an average of 3 to 10 nights each month from the end inches. A :now cover generally remains on the ground of November through February. more than half the time between the middle of December The number of clear or only partly cloudy days each and the end of February. Snow reaches a depth of 6 to month increases from less than 10 in midwinter to 25 or 10 inches almost every winter, and depths ranging from 20 more in midsummer. Sunshine data recorded at to 28 inches have been recorded during the seasons of Spokane is fairly representative of this area. Possible heaviest snowfall. A Chinook wind

In the original manuscript, there was a table in this space. All tables have been updated and are available as a separate document.

sunshine during each month ranges from 20 to 30 Calcareous soil. A soil containing enough calcium carbonate percent in winter, 50 to 60 percent in spring and fall, (commonly with magnesium carbonate) to effervesce (fizz) visibly when treated with cold, dilute hydrochloric acid. A soil and 80 percent or more in summer. The number of having measurable amounts of calcium carbonate or magnesium hours of possible sunshine on a clear day ranges from 8 carbonate. in December to 16 in June. Clay. As a soil separate, the mineral soil particles less than During summer, the prevailing direction of the wind is 0.002 millimeter in diameter. As a soil textural class, soil material that is 40 percent or more clay, less than 45 percent from the southwest and the average velocity ranges sand, and less than 40 percent silt. from 7 to 8 miles per hour. Velocities more than 20 Colluvium. Soil material, rock fragments, or both moved by creep, miles per hour seldom occur. During fall and winter, the slide, or local wash and deposited at the bases of steep frequency of winds from a northeasterly direction slopes. Complex slope. Irregular or variable slope. Planning or con- increases. In some winter months, the number of days structing terraces, diversions, and other water-control measures with winds from an easterly quadrant exceeds the is difficult. number from a westerly quadrant. The highest wind Consistence, soil. The feel of the soil and the ease with which a velocities are from the southwest or west and are lump can be crushed by the fingers. Terms commonly used to frequently associated with rapidly moving weather describe consistence are systems. Extreme wind velocities at an elevation of 30 Loose.-Noncoherent when dry or moist; does not hold to gether in a mass. feet can be expected to reach 50 miles per hour at least Friable.-When moist, crushes easily under gentle pressure once in 2 years, 65 to 75 miles per hour once in 50 between thumb and forefinger and can be pressed to years, and 80 miles per hour once in 100 years. gether into a lump. Firm.-When moist, crushes under moderate pressure between thumb and forefinger, but resistance is distinctly notice References able. Plastic.-When wet, readily deformed by moderate pressure (1) American Association of State Highway [and Transportation but can be pressed into a lump; will form a "wire" when Officials]. 1970. Standard specifications for highway materials rolled between thumb and forefinger. and methods of sampling and testing. Ed. 10, 2 vol., illus. Sticky.-When wet, adheres to other material and tends to (2) American Society for Testing and Materials. 1974. Method for stretch somewhat and pull apart rather than to pull free classification of soils for engineering purposes. ASTM Stand. D 2487-69. In 1974 Annual Book of ASTM Standards, Part from other material. 19, 464 pp., illus. Hard.-When dry, moderately resistant to pressure; can be (3) Bretz, Harlen J. 1959. Washington's channeled scabland. Wash. broken with difficulty between thumb and forefinger. Dept. of Conserv. Div. of Mines and Geol., Bull. No. 45, 57 Soft.-When dry, breaks into powder or individual grains pp., illus. under very slight pressure. (4) Meyer, W H. 1938. Yield of even-aged stands of ponderosa Cemented.-Hard; little affected by moistening. pine. U.S. Dep. Agric. Tech. Bull. 630, 59 pp., illus. Contour stripcropping (or contour farming). Growing crops in (5) Portland Cement Association. 1962. PCA soil primer. 52 strips that follow the contour. Strips of grass or closegrowing pp., illus. crops are alternated with strips of clean-tilled crops or (6) United States Department of Agriculture. 1951. Soil survey summer fallow. manual. U.S. Dep. Agric. Handb. 18, 503 pp., illus. [Sup- Contour tillage. Plowing, cultivating, planting, and harvesting in plements replacing pp. 173-188] rows that are at right angles to the natural direction of the (7) ____. 1975. Soil taxonomy: a basic system of soil classification slope or that are parallel to terrace grade. for making and interpreting soil surveys. U.S. Dep. Agric. Crop rotation. The growing of different crops in recurring suc- Handb. 436, 754 pp., illus. cession on the same field. Cross-slope farming. Plowing, cultivating, planting, and harvesting across the general slope, but not on the contour as in contour farming. Glossary Cutbanks cave. Unstable walls of cuts made by earthmoving equipment. The soil sloughs easily. Alluvium. Material, such as sand, silt, or clay, deposited on land by Dendritic drainage. A drainage pattern in which . the streams streams. branch irregularly in many directions and at almost any Area reclaim. An area difficult to reclaim after the removal of soil angle, resembling in plan the branching of certain trees, as for construction and other uses. Revegetation and erosion oaks or maples. control are extremely difficult. Depth, soil. Five general depth classes of soil to bedrock, hard- Ash, volcanic. Consists of small particles of solid or porous pan, sand and gravel, or other layer are recognized; (1) fragments of obsidian or pumice, which look like coarse ashes, Very shallow-5 to 10 inches deep; (2) Shallow-10 to 20 ejected in volcanic activity. inches deep; (3) Moderately deep-20 to 40 inches deep; (4) Available water capacity (available moisture capacity). The Deep-40 to 60 inches deep; and (5) Very deep-more than 60 capacity of soils to hold water available for use by most inches deep. plants. It is commonly defined as the difference between the Depth to rock. Bedrock at a depth that adversely affects the amount of soil water at field moisture capacity and the amount specified use. at wilting point. It is commonly expressed as inches of water per Divided slopes. Protecting slopes where stripcropping is im- inch of soil. The capacity, in inches, in a 60inch profile or to a practical by dividing them once. A strip of grain and a strip of limiting layer is expressed as peas, lentils, spring grain, or fallow are alternated yearly, or Inches legumes and grass are grown on one of the strips. Low ------0 to 3.75 Drainage class (natural). Refers to the frequency and duration of Moderate ------3.75 to 5.0 periods of saturation or partial saturation during soil Moderately high ------5.0 to 7.5 formation, as opposed to altered drainage, which is commonly the result of artificial drainage or irrigation but may be caused High ------More than 7.5 by the sudden deepening of channels or the blocking of drainage Base saturation. The degree to which material having base ex- outlets. Seven classes of natural soil drainage are recognized: change properties is saturated with exchangeable bases (sum of Excessively drained.-Water is removed from the soil very Ca, Mg, Na, K), expressed as a percentage of the exchange rapidly. Excessively drained soils are commonly very capacity. coarse textured, rocky, or shallow. Some are steep. All Bottom land. The normal flood plain of a stream, subject to are free of the mottling related to wetness. frequent flooding. Somewhat excessively drained.-Water is removed from the soil rapidly. Many somewhat excessively drained soils

are sandy and rapidly pervious. Some are shallow. Some are Frost action. Freezing and thawing of soil moisture. Frost ac so steep that much of the water they receive is lost as tion can damage structures and plant roots. runoff. All are free of the mottling related to wetness. Gravel. Rounded or angular fragments of rock up to 3 inches Well drained.-Water is removed from the soil readily, but not (2 millimeters to 7.5 centimeters) in diameter. An individual rapidly. It is available to plants throughout most of the piece is a pebble. growing season, and wetness does not inhibit growth of roots Herbage. Sum total of all annual growth of grasses and forbs. for significant periods during most growing seasons. Well Horizon, soil. A layer of soil, approximately parallel to the sur drained soils are commonly medium textured. They are mainly free of mottling. face, having distinct characteristics produced by soil-forming Moderately well drained.-Water is removed from the soil processes. The major horizons of mineral soil are as follows: somewhat slowly during some periods. Moderately well 0 horizon. An organic layer, fresh and decaying plant residue, drained soils are wet for only a short time during the at the surface of a mineral soil. growing season, but periodically for long enough that most A horizon.-The mineral horizon, formed or forming at or near mesophytic crops are affected. They commonly have a slowly the surface, in which an accumulation of humified organic pervious layer within or directly below the solum, or matter is mixed with the mineral material. Also, a plowed periodically receive high rainfall, or both. surface horizon most of which was originally part of a B Somewhat poorly drained.-Water is removed slowly enough that horizon. the soil is wet for significant periods during the growing A2 horizon.-A mineral horizon, mainly a residual concentration season. Wetness markedly restricts the growth of mesophytic of sand and silt high in content of resistant minerals as a crops unless artificial drainage is provided. Somewhat poorly result of the loss of silicate clay, iron, aluminum, or a drained soils commonly have a slowly pervious layer, a high combination of these. water table, additional water from seepage, nearly B horizon.-The mineral horizon below an A horizon. The B continuous rainfall, or a combination of these. horizon is in part a layer of change from the overlying A to Poorly drained.-Water is removed so slowly that the soil is the underlying C horizon. The B horizon also has distinctive saturated periodically during the growing season or remains characteristics caused (1) by accumulation of clay; wet for long periods. Free water is commonly at or near the sesquioxides, humus, or a combination of these; (2) by surface for long enough during the growing season that most prismatic or blocky structure; (3) by redder or browner colors mesophytic crops cannot be grown unless the soil is artificially than those in the A horizon; or (4) by a combination of drained. The soil is not continuously saturated in layers directly these. The combined A and B horizons are generally called the below plow depth. Poor drainage results from a high water solum, or true soil. If a soil lacks a B horizon, the A horizon table, a slowly pervious layer within the profile, seepage, alone is the solum. nearly continuous rainfall, or a combination of these. C horizon.-The mineral horizon or layer, excluding indurated Very poorly drained.-Water is removed from the soil so slowly bedrock, that is little affected by soil-forming processes and that free water remains at or on the surface during most of the does not have the properties typical of the A or B horizon. gowing season. Unless the soil is artificially drained, most The material of a C horizon may be either like or unlike mesophytic crops cannot be grown. Very poorly drained soils that from which the solum is presumed to have formed. If are commonly level or depressed and are frequently ponded. the material is known to differ from that in the solum the Yet, where rainfall is high and nearly continuous, they can Roman numeral II precedes the letter C. have moderate or high slope gradients, as for example in R layer.-Consolidated rock beneath the soil. The rock commonly "hillpeats" and "climatic moors." underlies a C horizon, but can be directly below an A or a B Erosion. The wearing away of the land surface by running water, horizon. wind, ice, or other geologic agents and by such processes as Large stones. Rock fragments 10 inches (25 centimeters) or gravitational creep. more across. Large stones adversely affect the specified use. Erosion (geologic). Erosion caused by geologic processes acting Low strength. Inadequate strength for supporting loads. over long geologic periods and resulting in the wearing away of Metasediments. Sediment or sedimentary rock that shows evidence of mountains and the building up of such landscape features as having been subjected to metamorphosis. flood plains and coastal plains. Synonym: natural erosion. Mottling, soil. Irregular spots of different colors that vary in Erosion (accelerated). Erosion much more rapid than geologic number and size. Mottling generally indicates poor aeration erosion, mainly as a result of the activities of man or other and impeded drainage. Descriptive terms are as follows: animals or of a catastrophe in nature, for example, fire, that exposes a bare surface. abundance-few, common, and many; size-fine, medium, Erosion hazard. Susceptibility to water erosion or soil blowing. The and coarse; and contrast-faint, distinct, and prominent. terms used in this survey are slight, moderate, high, and very The size measurements are of the diameter along the high. These terms are relative and apply only in relation to greatest dimension. Fine indicates less than 5 millimeters other soils of Whitman County. (about 0.2 inch) ; medium, from 5 to 15 millimeters (about Excess fines. Excess silt and clay. The soil does not provide a 0.2 to 0.6 inch); and coarse, more than 15 millimeters (about source of gravel or sand for construction purposes. 0.6 inch). Excess lime. Excess carbonates. Excessive carbonates, or lime, Outwash, glacial. Stratified sand and gravel produced by glaciers restrict the growth of some plants. Flooding. The temporary covering of soil with water from over- and carried, sorted, and deposited by water that originated flowing streams, runoff from adjacent slopes, and tides. mainly from the melting of glacial ice. The term glacial Frequency, duration, and probable dates of occurrence are outwash as used in this publication also includes glacial estimated. Frequency is expressed as none, rare, occasional, and flood deposits from Lake Missoula. Glacial outwash is com frequent. None means that flooding is not probable; rare that it monly in valleys on landforms known as valley trains, out is unlikely but possible under unusual weather conditions; wash terraces, eskers, kame terraces, kames, outwash fans, occasional that it occurs on an average of once or less in 2 years; or deltas. and frequent that it occurs on an average of more than once in 2 Paleosol. A buried soil, especially one formed during an inter years. Duration is expressed as very brief if less than 2 days, brief if 2 to 7 days, and long if more than 7 days. Probable glacial period and covered by deposits or a formerly buried dates are expressed in months; November-May for example, soil that has been exposed by the stripping of the overlying means that flooding can occur during the period November deposits by later advances of the ice. through May. Water standing for short periods after rainfall or Parent material. The great variety of unconsolidated organic commonly covering swamps and marshes is not considered and mineral material in which soil forms. Consolidated bed flooding. rock is not yet parent material by this concept. Flood plain. A nearly level alluvial plain that borders a stream and Ped. An individual natural soil aggregate, such as a granule, a is subject to flooding unless protected artificially. prism, or a block. Percs slowly. The slow movement of water through the soil adversely affecting the specified use. Permeability. The quality that enables the soil to transmit water or air, measured as the number of inches per hour that water moves through the soil. Terms describing permeability are very slow (less than 0.06 inch), slow (0.06 to 0.20 inch), moderately slow (0.2 to 0.6 inch), moderate (0.6 to 2.0

inches), moderately rapid (2.0 to 6.0 inches), rapid (6.0 to 20 Small stones. Rock fragments 3 to 10 inches (7.5 to 25 centimeters) in inches), and very rapid (more than 20 inches). diameter. Small stones adversely affect the specified use. Piping. Moving water forms subsurface tunnels or pipelike cavities Soil. A natural, three-dimensional body at the earth's surface that in the soil. is capable of supporting plants and has properties resulting Poor outlets. Surface or subsurface drainage outlets difficult or from the integrated effect of climate and living matter acting expensive to install. on earthy parent material, as conditioned by relief over periods Profile, soil. A vertical section of the soil extending through all its of time. horizons and into the parent material. Solifluction. The slow downslope flow, or creep, of waterlogged soil Reaction, soil. The degree of acidity or alkalinity of a soil, ex- or other loose material. Results in the formation of small pressed in pH values. A soil that tests to pH 7.0 is described as terraces common in arctic and mountain regions. precisely neutral in reaction because it is neither acid nor Solum. The solum part of a soil profile, above the C horizon, in alkaline. The degree of acidity or alkalinity is expressed as which the processes of soil formation are active. The solum in mature soil consists of the A and B horizons. Generally, the pH pH characteristics of the material in these horizons are unlike Extremely acid ___Below 4.5 Neutral ------6.6 to 7.3 those of the underlying material. The living roots and other Very strongly acid 4.5 to 5.0 Mildly alkaline ----- 7.4 to 7.8 plant and animal life characteristic of the soil are largely Strongly acid ----- 5.1 to 5.5 Moderately alkaline _7.9 to 8.4 confined to the solum. Medium acid ---- 5.6 to 6.0 Strongly alkaline ___8.5 to 9.0 Stripcropping. Growing crops in a systematic arrangement of Slightly acid ---- 6.1 to 6.5 Very strongly strips or bands which provide vegetative barriers to wind and alkaline ------9.1 and higher water erosion. Structure, soil. The arrangement of primary soil particles into Rooting depth. Shallow root zone. The soil is shallow over a compound particles or aggregates that are separated from layer that greatly restricts roots. adjoining aggregates. The principal forms of soil structure are- Runoff. The precipitation discharged in stream channels from a platy (laminated), prismatic (vertical axis of aggregates drainage area. The water that flows off the land surface longer than horizontal), columnar (prisms with rounded tops), without sinking in is called surface runoff; that which enters the blocky (angular or subangular), and granular. Structureless ground before reaching surface streams is called groundwater soils are either single grained (each grain by itself, as in dune runoff or seepage flow from ground water. sand) or massive (the particles adhering without any regular Saline-alkali soil. A soil that contains a harmful concentration of cleavage, as in many hardpans). salts and exchangeable sodium; contains harmful salts and is Subsoil. Technically, the B horizon; roughly, the part of the strongly alkaline or contains harmful salts and exchangeable solum below plow depth. sodium and is very strongly alkaline. The salts, exchangeable Substratum. The part of the soil below the solum. sodium, and alkaline reaction are in the soil in such location that Surface soil. The soil ordinarily removed in tillage, or its equivalent growth of most crop plants is less than normal. in uncultivated soil, ranging in depth from 4 to 10 inches (10 Sand. As a soil separate, individual rock or mineral fragments from to 25 centimeters). Frequently designated as the "plow layer," 0.05 millimeter to 2.0 millimeters in diameter. Most sand or the "Ap horizon." grains consist of quartz. As a soil textural class, a soil that is 85 Texture, soil. The relative proportions of sand, silt, and clay percent or more sand and not more than 10 percent clay. particles in a mass of soil. The basic textural classes, in Scabland. Land, mainly flat and basalt-covered, that has a thin soil order of increasing proportion of fine particles, are sand, cover, sparse vegetation, and deep, dry channels (channeled loamy sand, sandy loam, loam, silt, silt loam, sandy clay scabland) scoured into the surface. loam, clay loam, silty clay loam, sandy clay, silty clay, and Seepage. The rapid movement of water through the soil. Seepage clay. The sand, loamy sand, and sandy loam classes may be adversely affects the specified use. further divided by specifying "coarse," "fine," or "very fine." Shrink-swell. The shrinking of soil when dry and the swelling Tilth, soil. The condition of the soil, especially the soil structure, as when wet. Shrinking and swelling can damage roads, dams, related to the growth of plants. Good tilth refers to the friable building foundations, and other structures. It can also damage state and is associated with high noncapillary porosity and plant roots. stable structure. A soil in poor tilth is nonfriable, hard, Silt. As a soil separate, individual mineral particles that range in nonaggregated, and difficult to till. diameter from the upper limit of clay (0.002 millimeter) to the Water table. The upper limit of the soil or underlying rock lower limit of very fine sand (0.05 millimeter). As a soil material that is wholly saturated with water. textural class, soil that is 80 percent or more silt and less than Water table, apparent. A thick zone of free water in the soil. 12 percent clay. Slick spot. Locally, a small area of soil having a puddled, crusted, or An apparent water table is indicated by the level at which smooth surface and an excess of exchangeable sodium. The soil water stands in an uncased borehole after adequate time is generally silty or clayey, is slippery when wet, and is low in is allowed for adjustment in the surrounding soil. productivity. Water table, artesian. A water table under hydrostatic head, Slope. The inclination of the land surface from the horizontal. generally beneath an impermeable layer. When this layer Percentage of slope is the vertical distance divided by hori- is penetrated, the water level rises in an uncased borehole. zontal distance, then multiplied by 100. Thus, a slope of 20 Water table, perched. A water table standing above an un percent is a drop of 20 feet in 100 feet of horizontal distance. saturated zone. In places an upper, or perched, water table is separated from a lower one by a dry zone.