Summary Table: Characteristics of the Ecoregions of Nevada

5 . SIERRA NEVADA 1 3 . CENTRAL BASIN AND RANGE (continued) Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 miles) (feet) Regimes (inches) (days) July min/max (oF) miles) (feet) Regimes (inches) (days) July min/max (oF) 5a. Mid-Elevation 237 Low mountain slopes, ridges, and alluvial fans of 5000-7500/ Quaternary colluvium and glacial outwash. Mollisols Fraval, Corbett, Frigid/ 14-35 50-100 19/41; Mixed conifer forest/ Jeffrey pine, ponderosa pine, sugar pine, Open, mixed evergreen forests, shrubland, and grassland. Logging, wildlife habitat, 13x. Sierra Nevada- 1619 Mid-elevation mountain slopes, crests, ridges, 6500-9000/ Quaternary colluvium and basalt fl ows. Mollisols (Argixerolls), Cagle, Duco, Hyloc, Mesic, Frigid/ 10-16 Less than 19/42; Mostly juniper–pinyon woodland. Highest areas: mountain- Woodland, brushland, rangeland, wildlife habitat, and recreation. Historic gold and Sierra Nevada fault block mountain ranges that are drained by 400-2500 Mostly Tertiary andesite and Mesozoic (Argixerolls), Entisols Toiyabe, Booford, Xeric, Aridic 46/78 white fi r, and incense cedar. Forest openings: fi re-maintained rangeland, woodland grazing, and recreation. Some placer gold mining. Streams Infl uenced and plateaus that are contiguous with or near the 400-2500 Tertiary andesite and tuffs. Mesozoic Alfi sols (Durixeralfs), Ister, Borealis, Aridic 70-120 49/81 mahogany/ Singleleaf pinyon, Utah juniper, low sagebrush, silver mining. Amalgamation processes from late-19th century mines elevated metal medium-gradient, cool, perennial or intermittent granitic rocks; some Jurassic-Triassic shale, (Xeropsamments), Jumbo, Duckhill, bordering on chaparral with manzanita, mountain-mahogany, snowberry, have been diverted to irrigate cropland in lower elevation ecoregions. Lake trout, Sierra Nevada. Seasonal pools and small lakes granitic rocks dominated by quartz Entisols (Xerorthents) Powment bordering on Wyoming big sagebrush, mountain big sagebrush, antelope and concentrations (particularly mercury) in some streams. Active sand, gravel, and gold streams. Riffl e substrates are composed of sandstone, volcaniclastic rocks, andesite, Alfi sols (Haploxeralfs) Inville, Softscrabble, Xeric serviceberry, mountain big sagebrush, Sierra chinquapin, antelope kokanee, brown trout, rainbow trout, and mountain whitefi sh are found in Lake Ranges are scattered throughout the ecoregion. Perennial monzonite and granodiorite. Cretaceous Xeric desert bitterbrush, green ephedra, currant, bottlebrush squirreltail, mining. Includes streams that have been state-designated for protection as priority or cobbles and boulders. Snow-melt and springs and rhyolite. Rock outcrops occur. Gabica bitterbrush, and prostrate ceanothus. Tahoe. or intermittent, high- to medium-gradient, diorite. Jurassic-Triassic shale, sandstone, Thurber needlegrass, Sandberg bluegrass, bluebunch wheatgrass, critical cold water fi shery habitat. Stream diversions for agriculture occur. supply streams with water. cold streams occur. Perennial streams are most volcaniclastic rocks, andesite, and rhyolite. Indian ricegrass, and cheatgrass. Highest areas: mountain brush and common at high elevations. Riffl e sections Rock outcrops occur. small stands of white fi r, ponderosa pine, lodgepole pine, Jeffrey 5b. High Elevation 127 Glaciated. High mountain slopes, peaks, 7500-10800/ Quaternary colluvium, morainal deposits, Entisols Temo, Jorge, Meiss, Frigid, Cryic/ 35-55+. 30-80 18/39; Mostly lodgepole pine–subalpine forest/ Sierra red fi r, white fi r, Mostly mixed evergreen forests with a shrub understory; forests broken by subalpine generally have cobble substrates. pine, western white pine, and whitebark pine. Sierra Nevada ridges, lateral moraines, terminal moraines, and 400-3300 and alluvium. Mostly Tertiary andesite and (Cryopsamments), Tallac, Sibelia, Xeric Mostly 45/73 Jeffrey pine, Sierra lodgepole pine, mountain hemlock, western shrubland and meadows occur at higher elevations. Wildlife habitat and recreation. lakes. Streams are primarily high gradient and Mesozoic granitic rocks; some Jurassic- Andisols Fugawee, Carioca, falling as white pine, whitebark pine, Washoe pine, manzanita, snowbrush, Water quality is only lightly infl uenced by human activities. Streams contain non- 13y. Sierra Nevada- 261 High elevation mountains, ridges, hills, and 9000-13800/ Quaternary colluvium and volcanic ash. Mollisols (Argixerolls, Kiote, Hiridge, Frigid, Cryic/ 12-20 Less than 16/39; Mountain-mahogany/ Subalpine-alpine forbs, mountain big Brushland, shrubland, open evergreen forest, deciduous trees, rangeland, wildlife perennial. Many riffl es occur and have cobble or Triassic shale, sandstone, volcaniclastic (Haplocryands), Boomtown, Witefels snow. prostrate ceanothus, and dwarf sage. native brown, brook, and rainbow trout. The federally-threatened Lahontan cutthroat Infl uenced plateaus. Contains cold, high-gradient, headwater 400-4800 Quaternary breccia, andesite, and basalt. Argicryolls) Devils Aridic 60-100 45/76 sagebrush, low sagebrush, mountain-mahogany, and aspen groves. habitat, and in some areas, recreation. Historic gold and silver mining. Active gold boulder substrates. Snow-melt and cool springs rocks, andesite, and rhyolite. Rock outcrops Inceptisols trout occur in the Truckee River system. streams that are fed by springs and snow- Mesozoic granitics dominated by quartz bordering on Scattered individuals or small stands of high elevation conifers. mines. supply streams with water. are common. (Dystroxerepts, High Elevation melt. Riffl e sections have cobble and boulder monzonite and granodiorite. Cretaceous Xeric, Xeric Dystrocryepts), Alfi sols Mountains substrates. diorite. Jurassic-Triassic shale, sandstone, (Haploxeralfs) volcaniclastic rocks, andesite, rhyolite, and granitic rocks. Rock outcrops are common. 13z. Upper 4628 Nearly fl at to rolling, broad valleys containing 4000-6200/ Valleys: mostly Quaternary alluvial, playa, Entisols (Fluvaquents, Sonoma, Wendane, Mesic/ 5-10 90-120 12/44; Mostly saltbush–greasewood and Great Basin sagebrush Shrubland, rangeland, wildlife habitat, recreation, home sites, and irrigated Lahontan Basin lake plains, alluvial fans, bajadas, a few hills, Mostly less and marsh deposits. Contained pluvial lakes Torriorthents), Aridisols Bubus, Dun Glen, Aridic 48/92 community/ Shadscale, black greasewood, rabbitbrush, bud pastureland and cropland. Stream diversions for agriculture are common. Livestock and eroded gullies. Drained by medium- to low- than 50-500; during the Pleistocene. Hills: Tertiary silicic (Haplocambids, Tenabo, Orovada, bordering on sagebrush, Wyoming big sagebrush, spiny hopsage, fourwing grazing has reduced native grasses and biological soil crusts. Historic gold, silver, 1 3 . CENTRAL BASIN AND RANGE gradient, perennial, intermittent, or ephemeral maximum ash-fl ow tuffs and tuffaceous rocks. Natrargids, Natridurids, Bliss, Weso, Wholan, Xeric, Aridic saltbush, inland saltgrass, alkali sacaton, seepweed, bottlebrush and mercury mining. Active sand, gravel, and gold mines; mine de-watering streams. Riffl e sections have substrates composed 800 Haplodurids), Ricert, Ocala, squirreltail, Indian ricegrass, creeping wildrye, Great Basin has occurred since the mid-1990s. Some streams have been state-designated for Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use of cobble-size or smaller material. A few hot Inceptisols Dunphy wildrye, Sandberg bluegrass, and Thurber needlegrass. Bud protection as priority or critical cold water fi shery habitat. Higher elevation streams springs occur. (Halaquepts) sagebrush and Indian ricegrass are not as abundant as in Ecoregion associated with the Quinn River drainage support populations of the federally- Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation 13j. Wildfi res caused by lightning are common; a post-fi re threatened Lahontan cutthroat trout. Hot springs infl uence water quality in streams. (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 monoculture of cheatgrass tends to replace native grasses and miles) (feet) Regimes (inches) (days) July min/max (oF) shrubs. 13a. Salt Deserts 799 Nearly level playas, salt fl ats, mud fl ats, 4250-6000/ Quaternary playa and marsh deposits; also Aridisols (Aquisalids), Mostly playa; also Mesic/ 5-8 110-160 10/44; Mostly barren; also saltbush–greasewood/ Vegetation is mostly Mostly barren. Wildlife habitat, recreation, and military reservations. Very low 13aa. Sierra Nevada- 2142 Mosaic of terraces, fl oodplains, hills, alluvial Mostly Quaternary alluvium. Tertiary andesite, Mollisols (Endoaquolls, Haybourne, Reno, Mesic/ 7-15 80-135 16/46; Great Basin sagebrush community in east and sagebrush steppe in Shrub- and grass-covered. Rangeland, wildlife habitat, irrigated pastureland, low terraces, and saline lakes. Perennial or 0-50 aeolian deposits. Strongly alkaline, clayey Inceptisols Saltair and Wendane. Aridic 48/92 absent; only scattered, extremely salt-tolerant plants occur such grazing potential. Spring outfl ows provide water for endemic fi shes such as the Infl uenced fans, bajadas, mountain fl anks, and canyons. 4000-6400; basalt, silicic ash-fl ow tuffs, and tuffaceous Haploxerolls, Jubilee, Voltaire, Aridic 48/92 west/ Wyoming big sagebrush, antelope bitterbrush, desert peach, irrigated alfalfa, and small grain farming. Expanding residential and commercial intermittent hot springs are common and lacustrine sediments are characteristic. (Halaquepts) Soils are mostly as pickleweed, seepweed, black greasewood, iodinebush, inland Independence Valley tui chub, Newark Valley tui chub, Diamond Valley speckled Semiarid Hills Cold, perennial, high- to moderate-gradient some hills sedimentary rock. Mesozoic granitic Argixerolls), Aridisols Surprise, Acrelane, bordering on low sagebrush, Lahontan sagebrush, Douglas rabbitbrush, Nevada areas occur. Grazing has reduced native grasses and biological soil crusts. Heavy scattered dunes occur. Internally drained by During the Pleistocene, extensive pluvial clayey, light-colored, saltgrass, and alkali sacaton. dace, relict dace, and the federally-endangered Clover Valley speckled dace and streams are fed by snow-melt and springs. Riffl e to 7000/ rocks dominated by quartz monzonite (Haplocambids, Old Camp, Deven, Xeric ephedra, bottlebrush squirreltail, desert needlegrass, Thurber agricultural water use and many stream diversions for agriculture occur in lower intermittent and ephemeral streams that can be lakes and marshes occurred. strongly affected by Independence Valley speckled dace. Spring outfl ows are commonly diverted for and Basins sections have cobble or boulder substrates. Mostly less and granodiorite. Jurassic-Triassic shale, Argidurids, Haplargids, Galeppi, Mottsville, needlegrass, Indian ricegrass, cheatgrass, bluebunch wheatgrass, elevation areas (e.g. Carson River and East and West Walker River). Historic gold alkaline. Low-lying areas are ponded during wet salt and alkali, poorly agricultural use. than 50- sandstone, volcaniclastic rocks, andesite, Paleargids) Phing, Holbrook, Sandberg bluegrass, and scattered juniper. Riparian cottonwood and silver mining. Extensive, active sand, gravel, clay, limestone, and gold mining. intervals. Water levels rise and fall seasonally and drained, and salt- 1500; some and rhyolite. Koontz, Xman woodland with buffaloberry along major rivers. Water quality is better at higher elevations. Some streams have been state-designated from year-to-year. Eroded by wind when dry. crusted. areas to for protection as priority or critical cold water fi shery habitat. Some stream segments 2400 associated with the Truckee and Walker rivers support sensitive resident cold water 13b. Shadscale- 3161 Mostly gently sloping to nearly fl at valley 4100-6200/ Mostly Quaternary alluvium; also loess, Entisols (Torriorthents), Unsel, Jolan, Ocala, Mesic/ 5-10 100-160 10/44; Mostly saltbush–greasewood; also Great Basin sagebrush Shrubland, rangeland, and wildlife habitat. Some areas are irrigated for small fi sh species such as the federally-threatened Lahontan cutthroat trout. Dominated bottoms with remnant lake terraces and scattered 25-1200 lacustrine, and dune deposits. During the Aridisols (Haplodurids, Sondoa, Batan, Aridic 44/92 community/ Principally black greasewood, shadscale, bud grains or alfalfa. Where cropland is present, streams are usually diverted for sand dunes; also fan skirts. Internally drained by Pleistocene, extensive pluvial lakes and Haplargids), Inceptisols Swingler, Tooele, sagebrush, fourwing saltbush, rubber rabbitbrush, alkali sacaton, agricultural use. Cattle sometimes graze in shallow wetland habitats created Saline Basins a few small intermittent or ephemeral streams. marshes occurred. (Halaquepts) Sodhouse. Soils bottlebrush squirreltail, inland saltgrass, Indian ricegrass, Great from springs. Valleys along the Nevada-Utah border have been degraded by past Storm runoff can contain high sediment loads. are light in color, Basin wildrye, and galleta. Local stands of Rocky Mountain juniper livestock management practices. Dune areas support highly diverse rodent and affected by salt and occur. reptile communities. Streams contain endemic fi shes such as the Diamond Valley alkali, and dry for speckled dace, Independence Valley tui chub, Newark Valley tui chub, White River extended periods. speckled dace, White River desert sucker, relict dace, and the federally-endangered Independence Valley speckled dace, White River spinedace, Moorman White River 1 4 . MOJAVE BASIN AND RANGE springfi sh, and Clover Valley speckled dace. Ponds near Shoshone in Spring Valley support the federally-endangered Pahrump poolfi sh. Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use 13c. Sagebrush 761 Valleys, basin rims, lake terraces, alluvial fans, 4900-6600/ Mostly Quaternary alluvium. Also Aridisols (Haplargids, Xerxes, Lembos, Mesic/ 8-12 100-160 10/39; Great Basin sagebrush community/ Wyoming big sagebrush, Shrubland, rangeland, wildlife habitat, and cropland. Livestock grazing has reduced Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation Basins and low hills, and foothills that are internally drained 100-1000 Quaternary colluvium, Tertiary rhyolite, Haplocalcids, Amtoft, Tarnach. Aridic 52/90 antelope bitterbrush, bluebunch wheatgrass, Indian ricegrass, and native grasses and biological soil crusts. Many streams are diverted for livestock and (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 by a few ephemeral, intermittent, or perennial andesite, and tuffaceous sedimentary rocks, Argidurids) Soils are dry for bordering on Thurber needlegrass along with scattered, invading Utah juniper. cropland uses. miles) (feet) Regimes (inches) (days) July min/max (oF) Slopes streams. Small impoundments occur. and Paleozoic sedimentary rocks dominated extended periods. Xeric On rocky, shallow soils: black sagebrush. Fire has widely destroyed by limestone and dolomite. sagebrush allowing non-native cheatgrass to expand. 14a. Creosote Bush- 5973 Valleys containing stream terraces, fl oodplains, Mostly Mostly Quaternary alluvium; also Aridisols (Petrocalcids, Canoto, Vace, Mesa, Thermic, 3-9. 170-280 20/56; Mostly creosote bush/ Sparse creosote bush, white bursage, cacti, Covered by scattered shrubs, cacti, and grasses. Rangeland (with a low carrying Dominated alluvial fans, isolated hills, mesas, buttes, and 1800-4500; Quaternary playa, marsh, and alluvial fl at Haplocalcids), Entisols Weiser, Wechech, Hyper- Generally 60/102 yucca, ephedra, big galleta, and Indian ricegrass. Mesquite and capacity for cattle), wildlife habitat, urban development, military bases, recreation, 13d. Woodland- and 1649 Low mountain ranges, mountain slopes, ridges, Mostly Quaternary alluvium and colluvium. Mollisols (Argixerolls, Pioche, Itca, Mesic, Frigid/ 10-18. 75-120 19/42; Mostly juniper–pinyon woodland/ Extensive, open Utah juniper Woodland, shrubland, grassland, rangeland, and wildlife habitat. Large areas have eroded washes. Perennial or ephemeral, low- to maximum deposits. Scattered hills: Tertiary andesite, (Torriorthents) Tonopah, Mormon, thermic/ winter acacia increase toward the south and east. Some areas are barren gravel operations, and some pastureland and cropland growing alfalfa hay and sod. Shrub-Covered hills, foothills, and alluvial fans. A few perennial 5000-9000; Tertiary rhyolitic and andesitic rocks, Durixerolls, Argiustolls, Motoqua, Segura, Aridic almost Receives 55/88 and singleleaf pinyon woodland. Wyoming, black, and mountain been cleared in an effort to increase livestock forage. Historic gold and silver mining. Basins medium-gradient, warm streams and rivers occur. 6200/ intrusive rocks, and tuffaceous sedimentary Nickel, Las Vegas, Aridic and spring of vegetation. Stony limestone soils: blackbrush common in the Historically, truck crops, almonds, apricots, and cotton were grown. Farmland in the Low Mountains or intermittent, medium- to low-gradient streams maximum tuffs, and tuffaceous sedimentary rocks. Calcixerolls), Entisols Cropper, Decan, Xeric, Aridic summer big sagebrush variously dominate the understory. SE Nevada: Substrates are composed of cobble, sand, or fi ne Less than rocks; Jurassic shale; Pennsylvanian St. Thomas. Soils are maximum transition to the Arid Footslopes (14b). Riparian natives: desert Las Vegas Valley has almost entirely been replaced by urban development. Historic occur and are fed by snow-melt and numerous 9300/ Paleozoic sedimentary rocks dominated (Torriorthents) Zoate, Linco, bordering on rainfall. understory includes Gambel oak, scrub oak, Joshua tree, and blue sediments. Surface waters are alkaline and have 100-400; limestone; Mississippian limestone; commonly gypsum- rainfall. willow, coyote willow, and mesquite. Tamarisk is rapidly replacing gold and silver mining and nuclear testing. Active sand, gravel, and limestone mining springs. 200-3300 by limestone and dolomite. Cambrian Clavicon. Soils are Ustic grama grass. Above elevational limit of pinyon: narrow band of high concentrations of calcium carbonate and mountains Ordovician limestone, dolomite, and shale; and limestone- Southeast: native desert riparian vegetation. operations are found near Las Vegas. Stream diversions are common. The Muddy quartzite. Rock outcrops occur. often rocky. bitterbrush, cliffrose, western serviceberry, and mountain big total dissolved solids. Flash fl ooding can follow to 1200 Cambrian limestone, dolomite, quartzite, infl uenced, light- summer River headwaters support the federally-endangered and endemic Moapa dace. sagebrush. thunderstorms. Reliable surface water is scarce. and shale; Precambrian gneiss and schist. colored, and alkaline. rainfall Upland habitat supports the federally-threatened desert tortoise. Riparian corridors 13e. High Elevation 916 Partially glaciated, high, rugged, mountains. 8500-13063/ Quaternary colluvium and glacial Mollisols (Calcicryolls, Guiser, Hardol, Cryic, Frigid/ 16-26+. Less than 15/39; Western spruce–fi r forest and Great Basin pine forest community/ Open forest, shrubland, grassland, summer rangeland, wildlife habitat, and becomes support several neo-tropical migrant bird species including the federally-endangered Headwaters for several perennial or intermittent 1000-4500 drift. Mostly Paleozoic carbonates and Haplocryolls, Agassiz, Hackwood, Xeric Receives 30-80 48/78 Stands of white fi r, Douglas-fi r, limber pine, and Engelmann spruce recreation. Limited numbers of Bonneville cutthroat trout inhabit streams in and near more southwestern willow fl ycatcher. Carbonate common. Mountains cold water streams fed by snow-melt and cold conglomerate, Cambrian quartzite and Haploxerolls, Hatur, Croesus summer with an understory of mountain big sagebrush, other mountain Great Basin National Park. springs. On porous limestone and dolomite: only conglomerate, and Precambrian quartzite. Cryrendolls), Alfi sols rainfall. brush species, and grasses. On carbonates above 9,500 feet 14b. Arid Footslopes 4133 Alluvial fans, hills, basalt fl ows, and low Mostly Quaternary colluvium and alluvium. Mostly Entisols St. Thomas, Yermo, Mostly 4-8 180-260 20/54; A diverse mixture of Mojavean forbs, shrubs, and succulents/ Open, multi-layered shrubland, rangeland, wildlife habitat, recreation, and military a limited amount of surfi cial water is available. Also Triassic rhyolite and sedimentary (Haplocryalfs) elevation: bristlecone pine. Limestone outcrops: curlleaf mountain- mountains drained by ephemeral streams, 2800-6200; Tertiary extrusive rocks and conglomerate. (Torriorthents); also Dedas, Upspring, Thermic/ 58/100 Scattered creosote bush, white bursage, Joshua trees and other reservations. Many reptile species occur. Upland areas support bighorn sheep. rocks and Mesozoic granitics. Rock mahogany. Limited areas of alpine meadows or tundra. springs, and washes. Storm events produce high maximum Jurassic siltstone, sandstone, carbonates, Aridisols (Argidurids, Zeheme, Iceberg, Aridic, Aridic yuccas, blackbrush, winterfat, spiny menodora, Nevada ephedra, big Historic gold and silver mining and nuclear testing. Active sand and gravel mines are outcrops occur. sediment yields. Reliable surface water is scarce 7200/ and shale. Triassic limestone, siltstone, and Haplocalcids, Haleburu, Zibate, bordering on galleta, Indian ricegrass, and annual fescue. On rocky sites: cacti found near Las Vegas and gold mines occur near Beatty. 13g. Wetlands 410 Flat to depressional terrain with saline, brackish, 3850-6100/ Quaternary playa, marsh, and alluvial Inceptisols Equis, Paranat, Mesic/ 4-10 90-130 48/94; Tule marshes/ Bulrushes, Baltic rush, cattails, burreed, reed grass Marshland, wildlife habitat, rangeland, cropland, and recreation. Water, marsh, or nonexistent. 200-2000 sandstone. Pennsylvanian-Mississippian Haplargids) Cruzspring Ustic including silver cholla and beavertail. Annual plants are episodically or freshwater wetlands. Some wetlands are 0-25 deposits. (Halaquepts), Mollisols Parran, Yobe Aridic, Aridic 10/44 (except in the Lahontan basin), inland saltgrass, alkali sacaton, and shore birds are common. Several state wildlife management areas and federal limestone. Devonian carbonates. abundant when suffi cient winter precipitation is received. perennial and are maintained by spring and (Endoaquolls), bordering on duckweed, widgeongrass, and iodine bush. The non-native tamarisk wildlife refuges occur. Marshes near Ruby Lake are critical trout and bass habitat Ordovician carbonates and shale. Cambrian groundwater fl ow. Others are ephemeral and Aridisols (Aquisalids) Xeric, Aquic tree has become common in many areas. Wetlands typically contain and contain relict dace. Farmland, home sites, and channelization have reduced carbonates and shale. Precambrian gneiss, are dependent on snow-melt from mountains; hardstem and alkali bulrushes on the margins of water areas more wetland acreage. Reclamation projects and irrigation seepage have created new schist, and granitics. Rock outcrops occur. they are susceptible to droughts and can dry up than 6 feet deep and cattails in water 3 to 6 feet deep. Shallow areas wetlands. Wetland water quality varies and depends upon season and amount of 14c. Mojave 594 Mid-elevation mountain slopes, ridges, and hills 6000-8000/ Quaternary colluvium. Triassic Mollisols (Haplustolls), Welring, Sed, Mesic, Frigid/ 10-16 90-150 26/46; Juniper–pinyon woodland/ Singleleaf pinyon, juniper, Gambel oak, Woodland, brushland, rangeland, recreation, and wildlife habitat containing seasonally. Ditches and dikes regulate water (1 to 12 inches) usually contain no vegetation or inland saltgrass (in irrigation return fl ow. Wetlands in Lahontan Valley and near Humboldt Lake are at Mountain drained by ephemeral streams, springs, and 400-2000 siltstone, limestone, and conglomerate. Entisols (Ustorthents), Lamadre, Seralin, Aridic 62/86 curlleaf mountain-mahogany, cliffrose, Wyoming big sagebrush, Mojavean fauna. Recreational use is especially heavy in the Spring Mountains east levels in many wetlands. saline conditions) or duckweed and widgeongrass (in less alkaline the terminus of rivers; they receive return fl ow from fl ood-irrigated fi elds which, in washes. Storm events produce high sediment Pennsylvanian limestone. Mississippian Aridisols (Haplargids, Pookaloo family, bordering on black sagebrush, serviceberry, snowberry, manzanita, ceanothus, of Pahrump. Historic gold and silver mining. Active gold mines are found south of conditions). turn, degrades water quality. Woodland and yields. Reliable surface water is scarce or limestone. Devonian dolomite and Haplocalcids) Schader Ustic, Aridic silktassel, and Apache plume. Above 7,500 feet elevation: Utah Las Vegas. Shrubland 13h. Lahontan and 2866 Broad, nearly level alkali fl ats, mud fl ats, playas, 3350-5500/ Mostly Quaternary playa, marsh, and Inceptisols Mostly playa; also Mesic/ 4-8 100-160 12/48; Mostly barren; also saltbush–greasewood/ Vegetation is mostly Mostly barren. Wildlife habitat, recreation, and military reservation. Very limited nonexistent. There are no perennial streams. limestone. Silurian dolomite. Ordovician bordering on juniper is replaced by Rocky Mountain juniper. Highest elevations: dolomite and limestone. Cambrian Xeric mountain brush. On soils derived from carbonate rocks: cliffrose. Tonopah Playas lake plains, low terraces, paleobeaches, sand 0-50; alluvial deposits; also Quaternary aeolian (Halaquepts), Entisols Wendane, Mazuma, Aridic 48/96 absent. Only some scattered, extremely salt-tolerant plants such grazing potential and largely unsuitable as cropland. Historic placer gold mining dunes, and sand sheets. Isolated springs support commonly material. Once drowned by Lake Lahontan (Torriorthents, Slaw, Sondoa, Isolde, as alkali sacaton, inland saltgrass, and seepweed occur. Black along playa shorelines. Pyramid Lake, the terminus of the Truckee River, provides limestone and quartzite. Precambrian Canyons: ponderosa pine, Gambel oak, willow, black cottonwood, small wetlands. Saline lakes and marshes occur. nearly level and smaller, more ancient lakes in the Torrifl uvents, Wabuska, Lahontan, greasewood or four-winged saltbush may grow in the transition to the only habitat for the federally-endangered cui-ui sucker fi sh and also contains lake gneiss, schist, granitic rocks, and quartzite. serviceberry, snowberry, and manzanita. Water levels fl uctuate seasonally and from year- Tonopah area. Strongly alkaline, clayey- Torripsamments), Voltaire, Ragtown, the salt shrub community and often stabilize low sand dunes. dwelling populations of federally-threatened Lahontan cutthroat trout. 14d. Mojave High 110 Unglaciated, rugged, isolated, high elevation 7500-11918/ Quaternary colluvium. Pennsylvanian Inceptisols Rosespring, Bricone, Cryic, Frigid/ 16-25+. Less than 24/41; Great Basin pine forest/ Curlleaf mountain-mahogany, mountain Lower slopes: shrubland and brushland. Upper slopes: forests. Woodland grazing, to-year. Water is more alkaline than in higher silty lacustrine sediments occur. Aridisols (Natrargids) Appian, Bubus. Soils Elevation mountains. Dry washes are common even at high 800-3900 limestone. Mississippian limestone. (Eutrocryepts), Paunsaugunt family Mostly Aridic Precipitation 50-100 55/78 big sagebrush, and both ponderosa pine and white fi r forests. recreation, fi rewood gathering, and wildlife habitat. elevation ecoregions. Playas are ponded by are often strongly elevations but a few perennial streams also occur. Cambrian limestone, dolomite, and shale. Mollisols (Haplustolls, bordering on maximum Highest elevations: stands of limber and a few bristlecone pines. On runoff from higher areas during wet intervals and saline and alkaline. Mountains Water is primarily from snow-melt. Rock outcrops are common. Calciustolls), Entisols Ustic, Aridic during north- and east-facing slopes and in hollows: small aspen groves. eroded by wind when dry. (Cryorthents) bordering on summer. Geographic and climatic isolation is pronounced allowing new 13j. Lahontan Salt 9600 Rolling plains with alluvial fans, scattered hills Mostly Mostly Quaternary alluvial, lacustrine, Entisols (Torriorthents, Ricert, Stumble, Mesic/ 4-7 100-160. 12/46; Saltbush–greasewood/ Shadscale, bud sagebrush, Bailey Shrubland, rangeland, wildlife habitat, irrigated alfalfa and small grain farming, Xeric plant species to evolve and relict populations to persist. Many rare and endemic species occur. Shrub Basin and buttes, foothills, stream terraces, fl ood plains, 3400-5500/ playa, marsh, aeolian, and colluvial Torripsamments, Hawsley, Mazuma, Aridic, Aridic Affected 52/94 greasewood, Shockley desert thorn, Indian ricegrass, and Nevada urban areas, irrigated pastureland, and military reservations. Historic gold and silver and sand sheets in internally drained basins. Mostly 50- deposits. Lower areas were once drowned Xerofl uvents, Blacktop, Dia, Izo, bordering on by ephedra are common. On strongly saline and sodic areas: black mining. Active gold, limestone, sand, and gravel mining. Dunes retain moisture 14e. Arid Valleys and 1165 Arid canyons, benchlands, alluvial fans, terraces, Mostly Quaternary alluvium and colluvium. Aridisols Tonopah, Carrizo, Hyperthermic, 2-7 200-350 28/60; Creosote bush/ Creosote bush, white brittlebush, white bursage, Diverse, sparse shrubland, wildlife habitat, rangeland, and recreation. Historic gold Active and vegetation-stabilized sand dunes are 400. Hills by late Pleistocene pluvial lake systems. Torrifl uvents), Aridisols Lahontan, Voltaire, Xeric inversions. greasewood, inland saltgrass, alkali sacaton, and seepweed. Dunes: and support a relatively dense animal community. Streams have been diverted for Canyonlands and fl oodplains in the Colorado River corridor. 500-2000; Tertiary andesitic rocks, basalt, tuffaceous (Haplocalcids, Huevi, Carrwash, Thermic/ 68/110 mesquite, palo verde, and occasional Sonoran species such as and silver mining. Active sand and gravel mining operations are found near Las sometimes found on the lee side of physiographic and buttes: Tertiary basaltic, andesitic, rhyolitic, and (Natrargids), Mollisols Wabuska, Dithod, specialized plants including indigobush, four-wing saltbush, irrigation use, thereby reducing stream fl ow. Water quality has been moderately- Upland erosion potential is high. Concentrations maximum sedimentary rocks, intrusive rocks, and Haplodurids, Cheme, Arizo, Aridic ocotillo. Below 1,000 feet elevation: no white bursage. Along larger Vegas. Upland habitats support bighorn sheep. In many canyons, cold water fi sheries barriers. Perennial, intermittent, and ephemeral higher and tuffaceous rocks often underlie hills. (Haploxerolls, Fallon, Weena. Fine littleleaf horsebrush, dune horsebrush, and Indian ricegrass. to heavily-degraded by human activities. Stream diversions for agriculture and of total dissolved solids and calcium carbonate in 3400/ continental sedimentary rocks. Precambrian Haplogypsids), Entisols Sunrock, Haleburu, rivers: native riparian plants, such as Frémont cottonwood and occur. The razorback sucker, Colorado pikeminnow, humpback chub, bonytail streams occur. Medium-gradient streams have more rugged Endoaquolls), soils derived from Riparian woodland: Frémont cottonwood, coyote willow, silver evaporation have elevated dissolved salt concentrations in Walker Lake, endangering streams are also high. 100-2300 gneiss, schist, and granitic rocks. Rock (Torriorthents) Nipton, Govwash, willow, are being replaced by introduced tamarisk. chub, and woundfi n are all associated with the Colorado River and are all federally- riffl e sections with cobble substrates. Low- Inceptisols lacustrine sediment buffaloberry, and Russian olive along major rivers. its fresh water fi shery. The federally-threatened Lahontan cutthroat trout once thrived outcrops occur. Guardian, Riverbend endangered due to the introduction of non-native fi sh and the alteration of natural gradient streams are generally sediment laden. (Halaquepts) are common and in the Lahontan Basin but most populations have now been extirpated. The federally- habitat (including dams and diversions). The federally-endangered Moapa dace and Surface water is usually more alkaline than in can be saline and threatened desert dace is found in spring-fed areas near Soldier Meadows in western Virgin River chub are both found in the Muddy River and the latter is also found in nearby higher elevation ecoregions. alkaline. Humboldt County. the Virgin River. Riparian habitats support non-native fi sh such as largemouth bass, 13k. Lahontan 4766 Hills, upper alluvial fans, bajadas, and low Mostly Quaternary alluvium and colluvium. Aridisols (Haplargids, Theon, Old Camp, Mesic/ 6-12. 80-140 12/46; Great Basin sagebrush community and sagebrush steppe/ Wyoming Shrub- and grass-covered. Wildlife habitat, recreation, and active gold, silver, clay, black crappie, channel catfi sh, rainbow trout, striper bass, and carp. Sagebrush mountain slopes. Perennial, intermittent, and 4800-7000; Tertiary basalt, andesite, rhyolite, and Haplodurids), Mollisols Olac, Roca, Acrelane, Aridic Sierran 52/92 big sagebrush, Lahontan sagebrush, low sagebrush, littleleaf limestone, and gypsum mines. Extensive historic gold and mercury mining. Limited 14f. Mojave Playas 88 Broad, nearly level alluvial fl ats, muddy lake 1950-3400/ Mostly Quaternary playa, marsh, aeolian, Entisols Mostly playa; also Thermic/ 4-7 170-300 20/56; Mostly barren; also creosote bush/ Vegetation is mostly absent but Mostly barren. Wildlife habitat. Very limited grazing potential. Unsuitable as Slopes ephemeral streams occur. minimum tuffaceous rocks. Jurassic gabbro, basalt, (Argixerolls) Vanwyper, Wylo, bordering on rainshadow horsebrush, rabbitbrush, antelope bitterbrush, green ephedra, grazing potential; livestock grazing has reduced native grasses and biological soil plains, low terraces, sand sheets, and sand dunes. 0-50; and alluvial deposits. (Torripsamments, Bluepoint, Haymont Aridic 60/102 scattered, extremely salt-tolerant plants occur. Cold-intolerant trees cropland. 4300, siltstone, shale, sandstone, and carbonates. Shawave, Grumblen, Xeric, Aridic infl uence is desert needlegrass, bottlebrush squirreltail, Thurber needlegrass, crusts. Stream fl ows are generally diverted for agriculture before reaching main Intermittent saline lakes occur, episodically commonly Torriorthents), Aridisols and woody legumes, such as velvet ash and mesquite, sometimes maximum Cretaceous granitics. Triassic volcanics, Boomstick, Bliss, strong. Indian ricegrass, Sandberg bluegrass, and bluebunch wheatgrass. stem rivers. Water quality is moderately- to heavily-degraded by human activities. fi lling to support a large invertebrate fauna. nearly level (Haplocalcids) are found where there is suffi cient moisture, particularly toward the 8700/ breccia, and limestone. Permian chert, Perla Understory grasses increase in productivity toward the northeast. Includes both cold water fi sheries and warm water fi sheries. south. Locally, scattered creosote bush. 150-2200 argillite, and shale. Ordovician siliceous Introduced cheatgrass tends to replace the shrub community and and volcanic rocks. Cambrian sandstone, provides fuel for recurrent fi res. Summer lightning causes wildfi res. 14g. Amargosa Desert 1691 Nearly level to rolling, internally drained Mostly Valleys: Mostly Quaternary alluvium; Entisols (Torriorthents), Arizo, Yermo, Thermic/ 3-7. 180-300 26/60; Creosote bush/ Creosote bush, white bursage, wolfberry, shadscale, Shrubland, rangeland, wildlife habitat, home sites, recreation, dairy operations, shale and limestone. Rock outcrops occur. valleys that receive discharge from extensive 2000-4200; some Quaternary playa, marsh, and alluvial Aridisols Shamock, Sanwell. Aridic Precipitation 64/104 scattered Joshua trees and other yuccas, Indian ricegrass, and feed lots, and irrigated cropland growing alfalfa, sorghum, and pistachios. Historic underground water systems. Contains fl oodplains, isolated hills fl at deposits. Scattered hills: Tertiary (Haplocalcids, Scattered hills: St. maximum in forbs. Wetland oases occur where the Amargosa River surfaces gold and silver mining. Active sand, gravel, clay, and gold mining occur. Seeps and 13l. Lahontan 855 Low fault block mountains. Perennial and Mostly Quaternary colluvium. Tertiary basalt and Entisols (Torriorthents), Kram, Jobpeak, Mesic, Frigid/ 10-16 60-110 16/39; Mostly juniper steppe woodland/ Open stands of woodland Woodland, shrubland, and grassland, rangeland, and wildlife habitat. Streams are terraces, playas, sand sheets, sand dunes, lower to 6000/ ash-fl ow tuffs, tuffaceous sedimentary Haplodurids) Thomas, Nickel winter. In the and support many endemic plants. Amargosa River meadows are springs support endemic fi sh species. The Ash Meadows area supports threatened Uplands intermittent streams are fed by springs and snow- 6400-8800; tuff. Jurassic shale, siltstone, sandstone, Mollisols (Argixerolls, Hopeka, Sumine, Aridic 51/86 dominated by Utah juniper occur. Singleleaf pinyon occurs only on used by fi sh for spawning, rearing, and/or migration. Includes streams that have been alluvial fans, and scattered hills. Many hot Mostly less rocks, and rhyolitic fl ows; Devonian rainshadow dominated by inland saltgrass. The Ash Meadows area supports and endangered endemic fi sh species such as Ash Meadows Amargosa pupfi sh, Ash melt. Summer stream fl ow is generally low. minimum and carbonates. Triassic granite, andesite, Haploxerolls), Aridisols Tristan, Acrelane, bordering on Fairview Peak and in the Stillwater Range. Understory is composed state-designated for protection as critical or high priority fi shery habitat. Historic and cold springs in the Amargosa Valley. Both than 200; dolomite and limestone; Silurian dolomite. of the Spring many endemic plants such as Ash Meadows gumplant, Amargosa Meadows speckled dace, Warm Springs pupfi sh, and Devils Hole pupfi sh. 5500, rhyolite, and sandstone. Pennsylvanian (Haplargids) Duco, Roca, Xeric of mountain big sagebrush, Wyoming big sagebrush, black gold, silver, and mercury mining. Active gold mines are now reworking old mine intermittent and ephemeral washes and streams maximum Cambrian limestone, dolomite, and shale. Mountains. niterwort, Ash Meadows blazing star, Ash Meadows ivesia, and Ash maximum conglomerate, limestone, sandstone, and Reluctan, Golsum, sagebrush, low sagebrush, green ephedra, antelope bitterbrush, areas. occur and commonly have subsurface fl ow. Many 1000 Precambrian quartzite, phyllitic siltstone, Meadows milkvetch. 9800/ calcareous shale. Ordovician siliceous and Say, Old Camp, and rabbitbrush. Northern herbaceous layer: cool season grasses seeps and springs feed intermittent rivers and conglomerate, limestone, and dolomite. Mostly 500- volcanic rocks. Cambrian sandstone. Rock Belate, Glean, Ister such as Sandberg bluegrass, Thurber needlegrass, and bluebunch streams. 2800 outcrops are common. wheatgrass. Southern herbaceous layer: warm season grasses such as Indian ricegrass. Riparian vegetation can be lacking. 13m. Upper 5245 Broad, rolling plains with scattered buttes, hills, 4600-7700/ Quaternary alluvial and lake deposits. Aridisols (Haplargids, Hunnton, Vanwyper, Frigid, Mesic/ 8-16 70-120 6/40; Great Basin sagebrush community and sagebrush steppe/ Wyoming Shrub- and grass-covered. Mostly rangeland; some cropland especially near the Humboldt alluvial fans, foothills, and a few hot springs. 200-2000 Mostly Tertiary tuffaceous rocks, ash, and Haplocambids, Enko, Cleavage, Aridic 46/94 big sagebrush, Douglas rabbitbrush, bluebunch wheatgrass, Idaho Humboldt River. Grazing has affected sagebrush communities by reducing native Perennial or intermittent streams generally drain andesitic, rhyolitic, and basaltic rocks. Argidurids), Mollisols Orovada, Wieland, bordering on fescue, Sandberg bluegrass, bottlebrush squirreltail, bluebunch grasses and biological soil crusts. Historic gold, silver, and mercury mining Plains into the Humboldt River. Stream gradients are (Argixerolls, Stampede, Donna, Xeric wheatgrass, Thurber needlegrass, and Great Basin wildrye. On predominantly in the west. Today, mines are active in the Elko and Carlin areas. variable. High-gradient streams have many riffl e Durixerolls) Cotant, Roca, Trunk, shallow soils: low sagebrush. On soils derived from rhyolite: The Upper Humboldt River has been moderately- to heavily-degraded by human sections with cobble substrates. Lower gradient Ninemile, Brock, density of grass and forb species in the sagebrush understory tends activities. Tributary water quality has been lightly- to moderately-degraded by 2 2 . ARIZONA/NEW MEXICO PLATEAU streams have fewer riffl es and fi ner substrates. Ramires. Extensive to be higher than on soils derived from other rocks. Lightning fi res human activities. The Humboldt River contains largemouth and smallmouth black Stream fl ows vary seasonally. shallow, stony soils are common; cheatgrass tends to replace native grasses and shrubs bass, channel catfi sh, black bullhead, and carp. Some higher elevation tributaries Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use occur. Soils derived after fi re. contain the Columbia spotted frog and the federally-endangered Lahontan cutthroat Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation from rhyolite have trout. Other tributaries to the Humboldt River support a fi shery containing rainbow (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 a relatively high trout, brook trout, brown trout, and mountain whitefi sh. miles) (feet) Regimes (inches) (days) July min/max (oF) moisture content. 13n. Mid-Elevation 467 Partly glaciated, mid-elevation mountains and 6500-8500/ Quaternary colluvial and morainal deposits. Mollisols (Argixerolls, Sumine, Hendap, Frigid, Cryic/ 12-22+. 60-110 15/35; Juniper–pinyon woodland/ Mid-elevations: mostly singleleaf Woodland, shrubland, wildlife habitat, recreation, and rangeland. Historic lead and 22d. Middle Elevation 46 Dissected, rugged, middle elevation mountains, 4000-8066/ Quaternary colluvium. Mostly Precambrian Mollisols (Haplustolls), Seralin, Virgin Peak, Mesic, Frigid/ 8-18 90-180 27/47; Chaparral and juniper–pinyon woodland/ Between about 5,750 and Brushland, woodland, scattered forest, rangeland, and wildlife habitat. steep ridges, mesas, buttes, and canyons. 600-3000 gneiss and schist. In the south: Permian Entisols (Torriorthents), Boxspring, Nippeno, Aridic 67/89 8,000 feet elevation: mountain brush above and below isolated, Ruby foothills. Snow-melt, cold springs, and small 600-2000 Mostly Mesozoic granitic and metamorphic Haplocryolls, Cropper, Hapgood, Aridic Receives 50/78 pinyon and Utah juniper, mountain big sagebrush, Idaho fescue, zinc mining. Water quality is only lightly infl uenced by human activities. Many Mountains lakes feed many cold, high-gradient, perennial rocks; also Paleozoic sedimentary rocks Haploxerolls) Bullump, Segura, bordering on winter Sandberg bluegrass, and bluebunch wheatgrass. Higher elevations: streams have been state-designated for protection as critical or high priority fi shery limestone, Pennsylvanian limestone, Aridisols (Haplargids), Rosespring bordering on small stands of Rocky Mountain Douglas-fi r and Rocky Mountain Mountains streams. Stream fl ows are seasonally variable. and Precambrian metasedimentary and Quarz Xeric, Xeric rainfall. curlleaf mountain-mahogany and aspen groves. Bottoms: aspen habitat. The federally-threatened Lahontan cutthroat trout occurs in some streams. Mississippian limestone, Devonian Inceptisols Ustic white fi r. Between 5,000 and 5,750 feet elevation: Rocky Mountain sedimentary rocks. and cottonwood. Western slopes of the Ruby Mountains: mostly dolomite and limestone, and Cambrian (Eutrocryepts) juniper, singleleaf pinyon, Gambel oak, Utah serviceberry, sagebrush and mountain brush; only limited pinyon and juniper. limestone, dolomite, sandstone, quartzite, littleleaf mountain-mahogany, curlleaf mountain-mahogany, and shale. Rock outcrops occur. canyon maple, manzanita, ceanothus, and grasses. Below about 13o. High Elevation 123 Heavily glaciated, high elevation mountains 8500-11350/ Quaternary colluvial, morainal, and Mollisols (Argicryolls, Hackwood, Topeki, Cryic, Frigid/ 20-26+. 15-80 16/34; Great Basin pine forest community/ Scattered white fi r, limber pine, Open forests, woodland, shrubland, alpine meadows, subalpine meadows, rangeland, 5,000 feet elevation: desert scrub oak, singleleaf pinyon, Utah Ruby containing cirques, tarns, boulder fi elds, and 600-2800 periglacial deposits. Mostly Mesozoic Haplocryolls), Alfi sols Guiser, Witefels. Xeric, Aridic Receives 47/74 Engelmann spruce, whitebark pine and shrubs and grasses including wildlife habitat, and recreation. Includes designated wilderness. Water is only lightly juniper, and shrublands. On limestone: black sagebrush is common other glacial features. Extensive periglacial granitic and metamorphic rocks. Rock (Haplocryalfs), Entisols Shallow soils are bordering on winter mountain big sagebrush, low sagebrush, lupine, snowberry, curlleaf infl uenced by human activities. High mountain lakes contain brook trout, Lahontan in understory. On gneiss and schist: Wyoming big sagebrush is Mountains features occur including active solifl uction fi elds. outcrops are common. (Cryopsamments) common. Xeric rainfall. mountain-mahogany, sedges, Sandberg bluegrass, and Idaho fescue. cutthroat trout, and lake trout. common in understory. Small, clear, cold lakes and perennial streams are Little closed-canopy conifer forest occurs. Extensive aspen groves. fed by snow-melt and springs. Alpine tundra occurs on thin, poorly drained soils over impervious rocks. Rocky Mountain fl ora is dominant. 13p. Carbonate 9523 Nearly fl at to gently sloping basins, terraces, Mostly Basins and terraces: Quaternary alluvium. Aridisols (Haplodurids, Ursine, Jericho, Mesic, Frigid/ Mostly 100-140 10/44; Great Basin sagebrush community/ A mixture of sparse, carbonate- Shrubland. Mostly rangeland and wildlife habitat; some irrigated pastureland, Sagebrush fl oodplains, fan skirts, and lower hillslopes. 5300-7000; Hills, ridges, and buttes: Tertiary rhyolitic, Argidurids, Haplargids, Blimo, Abgese, Aridic 8-10. 48/92 and drought-tolerant shrubs including black sagebrush, winterfat, irrigated alfalfa, and small grain farming. Livestock grazing has reduced native Scattered rolling hills, ridges, and buttes occur. scattered andesitic, sedimentary, and granitic Haplocambids), Wiffo, Umil, Kobeh, bordering on Receives Wyoming big sagebrush, and rabbitbrush. The understory is grasses and biological soil crusts. Stream diversions for agriculture are common. Valleys Internally drained by low- to moderate-gradient, hills, ridges, rocks and tuffs. Mesozoic granitic rocks. Entisols (Torriorthents, Dewar, Enko, Xeric summer composed of grasses including bottlebrush squirreltail, Indian Stream quality has been heavily- to moderately-degraded by human activities. 8 0 . NORTHERN BASIN AND RANGE perennial, intermittent, or ephemeral streams. and buttes to Paleozoic sedimentary rocks dominated by Torrifl uvents) Hunnton, Alhambra. rainfall. ricegrass, bluebunch wheatgrass, and cheatgrass. In north: cool Water from springs in the upper portions of White River Valley provide downstream Stream fl ow is variable. Riffl e sections have 7600/ limestone and dolomite. Hard pan can limit season grasses. In south: warm season grasses occur with increasing habitat to endemic fi shes such as the Preston White River springfi sh, White River Level IV Ecoregions Physiography Geology Soils Climate Potential Natural Vegetation*/ Land Cover and Land Use substrates composed of cobble-size or fi ner 50-1000 root growth. summer rain. In Spring Valley: winterfat. speckled dace, White River desert sucker, and the federally-endangered White River material. A few hot springs occur. spinedace. Echo Canyon Reservoir east of Pioche contains the endemic Meadow Area Elevation/ Surfi cial and Bedrock Order (Great Group) Common Soil Series Temperature/ Precipitation Frost Free Mean Temperature Present Vegetation Valley Wash speckled dace and Meadow Valley desert sucker fi sh. The federally- (square Local Relief Moisture Mean annual Mean annual January min/max; *Source: Kuchler, 1964 threatened and endemic Big Spring spinedace is found near Panaca. miles) (feet) Regimes (inches) (days) July min/max (oF) 13q. Carbonate 6497 Mid-elevation moderately to steeply sloping Mostly Quaternary colluvium and alluvium. Entisols (Torriorthents), Zimbob, Hopeka, Mostly 9-15. 60-110 15/38; Mostly juniper–pinyon woodland; also some Great Basin sagebrush Woodland, shrubland, rangeland, wildlife habitat, and recreation. Woodlands were 80a. Dissected High 3537 Rolling, high volcanic plateaus dissected 4900-7300/ Mostly Quaternary alluvium and Tertiary Aridisols (Haplodurids, Bartome, Hunnton, Mesic, Frigid/ 8-16 70-120 10/38; Mostly sagebrush steppe/ Wyoming big sagebrush, low sagebrush, Shrub- and grass-covered. Primarily rangeland and wildlife habitat. Some irrigated mountains and ridges. Underground drainage is 6000-9000; Mostly Paleozoic sedimentary rocks Mollisols (Calcixerolls, Hyzen, Cavehill, Frigid; also Receives 51/84 community/ Singleleaf pinyon and/or Utah juniper with a diverse cleared to increase livestock forage and were also widely cleared for charcoal Woodland Zone Lava Plateau by deep, shear-walled canyons. Perennial, Less than basalt and tuffaceous sedimentary rock. Argidurids, Haplargids, Zapa, Zevadez, Mostly Aridic 46/90 Douglas rabbitbrush, bluebunch wheatgrass, Idaho fescue, pastureland and alfalfa, barley, and oat farming. At lower elevations, many stream common and many springs occur. Its moderate- minimum dominated by limestone and dolomite. Argixerolls, Pookaloo, Cropper, some Cryic/ summer understory of black sagebrush, Wyoming big sagebrush, mountain production between 1870 and 1900. Woodland has since recovered and is expanding ephemeral, or intermittent streams, rivers, and 100-1200 Some Quaternary playa and marsh deposits Haplocambids), Linkup, Chen, bordering on bottlebrush squirreltail, Sandberg bluegrass, Thurber needlegrass, diversions for agriculture. Active sand and gravel mining operations are found south to high-gradient, cold, perennial or intermittent 5400, Also Tertiary rhyolitic, andesitic, and Haploxerolls, Fera, Locane, Aridic rainfall. big sagebrush, littleleaf mahogany, curlleaf mountain-mahogany, into lower elevation sagebrush areas. Historic gold mining. Active mining is found reservoirs are fed by snow-melt and springs. and Tertiary rhyolitic and andesitic rocks Mollisols (Argixerolls, Dewar, Chuska, Xeric Indian ricegrass, and cheatgrass. Overgrazed areas: cheatgrass has of Jackpot. In general, water quality is lightly- to moderately-infl uenced by human streams are fed by snow-melt and springs. Stream maximum granitic rocks and tuffs, Mesozoic granitic Argicryolls, Ravenswood, bordering on cliffrose, green ephedra, bluebunch wheatgrass, Idaho fescue, pine near Ely, Eureka, and Pioche. Water quality has been lightly- to moderately-degraded Stream gradients, substrates, and seasonal fl ows and tuffs. Durixerolls) Jackpot, Enko, replaced depleted bunchgrasses. In rocky areas: black sagebrush activities. Concentrations of total dissolved solids and total suspended solids are low. fl ows vary seasonally. 9400/ rocks, and Precambrian metasedimentary Calcicryolls, Bartine, Fusulina, Xeric bluegrass, and bottlebrush squirreltail. In north: cool season grasses. by human activities. Some streams have been state-designated for protection as vary. Some streams (e.g. Salmon Falls Creek) Ackett, Stampede, and scattered junipers. Contains streams that have been state-designated for protection as critical or high 300-3000 and sedimentary rocks. Rock outcrops are Haplocryolls), Tica In south: warm season grasses. Pinyon decreases to the north. critical or high priority fi shery habitat. have medium- to high-gradients and cobble Donna, Orovada priority fi shery habitat. The South Fork Owyhee River has a warm water fi shery. common. Aridisols (Haplargids, substrates. Others, including the Owyhee River Other streams can support cold water fi sheries. Yellowstone cutthroat trout occur in Haplocalcids) system, have low- to medium-gradients and the Goose Creek drainage. 13r. Central Nevada 7629 Rolling to hilly, high elevation valleys. Level Mostly Mostly Quaternary alluvium and Tertiary Entisols (Torriorthents), Tulase, Hayeston, Mesic, Frigid/ 8-10 80-120 12/44; Mostly Great Basin sagebrush community/ Wyoming big sagebrush, Shrubland, grassland, rangeland, wildlife habitat, and some irrigated cropland cobble or pebble substrates. High Valleys ground is limited due to the encroachment 5000-7000; silicic ash-fl ow tuffs. Also Quaternary Aridisols (Haplargids, Armespan, Aridic 48/94 black sagebrush, shadscale, low Douglas rabbitbrush, littleleaf principally growing alfalfa. Rangeland can be heavily grazed. Stream diversions for 80b. Semiarid Hills and 1011 Hills, low mountains, and alluvial fans. Low- to 5800-8300/ Quaternary alluvium. Tertiary extrusives Mollisols (Argixerolls, Gollaher, Cleavage, Frigid, Mesic/ 10-20 50-110 15/35; Mostly sagebrush steppe and juniper–pinyon woodland/ Mountain Shrubland, grassland, woodland, rangeland, and wildlife habitat. Includes streams of alluvial fans. Eroded gullies are common minimum loess, lacustrine deposits, and colluvium Haplocalcids, McConnel, Old bordering on horsebrush, green ephedra, galleta, needleandthread, Indian agriculture are common. Springs support endemic fi sh including the Monitor Valley Low Mountains moderate-gradient, perennial, intermittent, or 400-2300 and tuffaceous sedimentary rock. Jurassic Haploxerolls), Aridisols Xica, Shalcleav, Aridic 49/83 big sagebrush, low sagebrush, scattered Utah juniper, bluebunch that have been state-designated for protection as critical or high priority fi shery and permanent lakes are absent. Spring- and 4200, and Mesozoic volcanic and granitic rocks. Haplocambids) Camp, Singatse, Xeric ricegrass, bottlebrush squirreltail, Thurber needlegrass, Sandberg speckled dace. Resident populations of cold water, threatened and endangered fi sh ephemeral streams occur. Riffl e segments are granitics. Triassic siltstones. Paleozoic (Haplocalcids), Entisols Tecomar, Kram, bordering on wheatgrass, Sandberg bluegrass, Great Basin wildrye, and Indian habitat. Water quality has been lightly- to moderately-degraded by human activities. mountain-fed streams fl ow into the ecoregion but maximum Rock outcrops occur. Pineval, Stewval, bluegrass, and cheatgrass. Valley bottoms: Wyoming big sagebrush including Lahontan cutthroat trout are associated with the Reese River and Edwards common. Stream fl ows are seasonally variable. carbonates, shale, sandstone, conglomerate, (Xerorthents) Sumine, Amtoft, Xeric, Xeric ricegrass. Above about 7,000 feet: mountain brush. On alluvial Historic gold mining occurred Montello. Yellowstone cutthroat trout occur in the may be intermittent. Low-gradient streams with 8000/ Jung, Buffaran, and associated grasses. Riparian habitat is generally lacking. Creek drainages. and quartzite. Rock outcrops occur. Ridgecrest fans: aspen groves. Riparian areas: aspen, Geyer willow, and Booth Goose Creek drainage. few riffl es occur. Substrates are composed of fi ne 100-2000 Rebel, Silverado, Volcanic hills and alluvial fans: black sagebrush. willow. sediment. Coils, Bucan 80d. Pluvial Lake 342 Nearly level to gently sloping, internally drained 4600-6200/ Quaternary lacustrine, playa, alluvium, and Entisols (Torriorthents), Mazuma, Mesic, Frigid/ 8-12 80-130 16/38; Sagebrush steppe/ Wyoming big sagebrush, basin big sagebrush, Shrub- and grass-covered. Mostly rangeland and wildlife habitat; some recreation, 3586 Mid-elevation mountain side slopes and summits. Mostly Quaternary colluvium. Tertiary andesite, Entisols (Torriorthents), Itca, Bellehelen, Frigid, Mesic, 12-18 60 -110 17/40; Juniper-pinyon woodland and mountain-mahogany/ Singleleaf Discontinuous open woodland, shrubland, rangeland, wildlife habitat, and recreation. 13s. Central Nevada Basins basins containing lake terraces, playas, beach Less than marsh deposits. Aridisols (Natrargids, Longdis, Dugway, Mostly Aridic 48/86 rubber rabbitbrush, Great Basin wildrye, bottlebrush squirreltail, irrigated pastureland, and irrigated cropland growing alfalfa. Water diversions for Mid-Slope Its perennial or intermittent, moderate-gradient 6500-8000; rhyolite, and tuffs. Mesozoic siltstone, Mollisols (Argixerolls, Hopeka, Sumine, Cryic/ 50/84 pinyon, Utah juniper, black sagebrush, Wyoming big sagebrush, Pinyon and juniper were widely cleared for charcoal production between 1870 and plains, stream terraces, intermittent lakes, fan 50-400 Paleargids, Spangenburg, bordering on Indian ricegrass, Sandberg bluegrass, Thurber needlegrass, and agriculture occur. Occasional vernal pool species are found near seasonal fresh-water Woodland and streams are fed by snow-melt and cold springs. minimum shale, sandstone, conglomerate, limestone, Haplocryolls) Ravenswood Aridic green ephedra, rabbitbrush, desert bitterbrush, Thurber needlegrass, 1900. Woodland has recovered, expanding into lower elevation sagebrush areas. skirts, and cool springs. Reliable surface water Haplocambids, Disabel, Enko, Xeric cheatgrass. In strongly saline and sodic areas: black greasewood, bodies. 6000, and granitics. Permian chert, argillite, bordering on Sandberg bluegrass, bluebunch wheatgrass, Idaho fescue, and Many stream diversions for agriculture occur. Extensive historic gold and silver is limited; water levels fl uctuate seasonally and Natridurids) Updike inland saltgrass, and seepweed. Brushland maximum and shale. Devonian carbonates, siltstone, Xeric cheatgrass. Overall, woodland is more limited than in other mid- mines. Active mining near Manhattan and Austin. Water quality is lightly- to heavily- from year-to-year. 8500/ and chert. Silurian dolomite. Ordovician elevation ecoregions. Highest elevations: mountain big sagebrush infl uenced by human activities. Water temperatures vary and a variety of warm water 400-2000 carbonates, chert, phyllite, quartzite, and and curlleaf mountain-mahogany. Rocky, shallow soils: woodland and cold water fi sheries occur. Resident populations of cold water, threatened and 80e. High Desert 56 Valley containing remnant wetlands, fl oodplains, 5300-5400/ Quaternary alluvium and lacustrine Mollisols (Argixerolls, Hayspur, Thacker, Frigid, Mesic/ 10-16 60-110 12/36; Sagebrush steppe/ In wettest areas: sedges, rushes, tufted hairgrass, Shrubland, grassland, wetland, rangeland, and wildlife habitat; also irrigated shale. Cambrian quartzite, sandstone, and with little or no shrub understory. Riparian areas: cottonwood, endangered fi sh including Lahontan cutthroat trout are associated with the Reese Wetlands alluvial terraces, lakes, and reservoirs. Its Less than sediment. Haploxerolls, Soonahbe, Aridic almost 44/86 meadow barley, creeping wildrye, and bluegrass. Elsewhere: pastureland and irrigated cropland growing alfalfa and barley. Marshes and lakes are limestone. Rock outcrops are common. aspen, water birch, chokecherry, and coyote willow. River drainage. Available riparian habitat may contain the Columbia spotted frog. perennial or ephemeral streams have low- to 25-100 Endoaquolls), Paynecreek, Zola, Xeric, Xeric. basin big sagebrush, Wyoming big sagebrush, silver sagebrush, critical habitat for nesting and migratory birds as well as associated upland birds and moderate-gradients. Alfi sols (Durixeralfs, Boulder Lake, Wettest: aquic Idaho fescue, Great Basin wildrye, Nevada bluegrass, bluebunch mammals. 13t. Central Nevada 1221 High elevation, moderately to steeply sloping 7500-11000/ Quaternary colluvium. Tertiary extrusive Mollisols (Argicryolls, Hapgood, Layview, Cryic, Frigid/ 14-25+ Less than 18/38; Mostly mountain-mahogany/ Mountain big sagebrush, low Brushland, shrubland, summer rangeland, wildlife habitat, recreation, and mining. Haploxeralfs), Vertisols Schamp, Fernpoint conditions in wheatgrass, Thurber needlegrass, and cheatgrass. Bald Mountains mountains and ridges. Contains moderate- to 600-3500 rocks. Triassic conglomerate, limestone, Haplocryolls, Packer, Foxvire, Xeric, Aridic 50-90 48/78 sagebrush, bitterbrush, snowberry, curlleaf mountain-mahogany, Because of fi re, aridity, and dense shrub cover, trees have not reestablished after (Epiaquerts), Aridisols growing season. high-gradient headwater streams that are fed by and siltstone. Permian chert, argillite, and Palecryolls, Flygare, Podmor, bordering on western serviceberry, Sandberg bluegrass, Idaho fescue, mountain early settlement, mining, and logging. Stream discharge and water quality are (Haplargids) cold springs and snow-melt. Riffl e sections have shale. Devonian carbonates. Ordovician Haploxerolls), Hackwood, Xeric brome, Thurber needlegrass, arrowleaf balsamroot. Highest peaks: typically only lightly infl uenced by human activities. Water temperatures vary cobble substrates. sandstone, volcanics, phyllite, chert, and Inceptisols Underdown family scattered limber pine and bristlecone pine. Moist sites: aspen. Crests and a wide range of warm water and cold water fi sheries occur. Populations of the 80g. High Lava Plains 5740 Nearly level to hilly, elevated volcanic plateau Mostly Quaternary colluvium, alluvium, and Mollisols (Argixerolls, Home Camp, New- Frigid, Cryic, 8-16 50-110 12/40; Sagebrush steppe/ Wyoming big sagebrush, low sagebrush, Shrub- and grass-covered. Mostly rangeland and wildlife habitat; some irrigated limestone. Cambrian limestone. Rock (Eutrocryepts) of the Toiyabe Range: alpine grasses, Drabas, and buckwheats. federally-threatened Lahontan cutthroat trout are associated with the Reese River with internal drainage. Scattered lakes and 4200-6800/ aeolian material derived from volcanic Argicryolls, lands, Softscrabble, Mesic/ 44/92 Lahontan sagebrush, bluebunch wheatgrass, Sandberg bluegrass, pastureland and cropland growing alfalfa, barley, and oats. Stream diversions for outcrops are common. Only Great Basin tree communities occur. and Edwards Creek drainages. ephemeral pools occur and support unusual fauna Mostly 100- ash. Mostly Tertiary basaltic, rhyolitic, and Durixerolls, Olson, Mascamp, Aridic Thurber needlegrass, bottlebrush squirreltail, and Idaho fescue. In livestock are common. Historic gold and silver mining in the northwest. Active assemblages. Lake and pool levels fl uctuate 2500 andesitic rocks as well as ash-fl ow tuffs. Haploxerolls), Millerlux, Powley, areas depleted by grazing: cheatgrass. opal mines occur south of Denio and clay quarries are found west of McDermitt. 13u. Tonopah Basin 9655 Broad, nearly fl at to rolling valleys containing 4000-7000/ Valleys: mostly Quaternary alluvial and Entisols (Torriorthents, Wardenot, Koyen, Mesic/ 3-9. 100-170 16/52; Mostly saltbush–greasewood; some Great Basin sagebrush Shrubland, rangeland, wildlife habitat, and some irrigated cropland growing alfalfa, seasonally and from year-to-year; reliable surface Aridisols (Haplargids, Fertaline, Bucklake, Productive fi sheries occur in small reservoirs or impoundments. Higher elevations lake plains, scattered hills, alluvial fans, bajadas, Less than lacustrine deposits. Once contained several Torripsamments), Rustigate, Penoyer, Aridic, Aridic Available 56/96 community/ Sparse stands of shadscale, bud sagebrush, spiny small grains, potatoes, or sugar beets. Pahranagat Valley has many springs that are water is limited. Argidurids, Natrargids) Vanwyper, Ninemile, once supported Lahontan cutthroat trout but water availability limits their present sand dunes, and hot springs. Ephemeral washes 50-1800 Pleistocene pluvial lakes and marshes. Aridisols (Haplargids, Gynelle, Cliffdown, bordering on summer hopsage, seepweed, fourwing saltbush, spiny menodora, Nevada used for agriculture, domestic purposes, and wildlife and support the federally- Glean, Catnip, Wylo distribution. The federally-threatened Warner sucker fi sh lives in permanent but occur. Surface water comes from springs and Hills: Tertiary andesite, basalt, silicic ash- Haplocambids, Tickapoo, Ardivey, Xeric moisture ephedra, littleleaf horsebrush, Douglas rabbitbrush, winterfat, endangered White River springfi sh, Hiko White River springfi sh, and Pahranagat shallow, weedy lakes and spawns in Twelvemile Creek in northwesternmost Nevada. sporadic foothill precipitation events but is fl ow tuffs, and tuffaceous sedimentary Natridurids, Candelaria, Stonell, increases inland saltgrass, and alkali sacaton. Alien and toxic halogeton is roundtail chub. Springs support endemic fi sh including the Railroad Valley tui chub The Wall Canyon area supports a unique fi sh species, the Wall Canyon sucker. generally scarce. rock; Jurassic shales, siltstone, andesite, Haplocalcids, Papoose, Silent, Izo, toward the common. Shrub understory contains warm season grasses including and the federally-threatened Railroad Valley springfi sh. Oil and gas production rhyolite, and volcaniclastics; Devonian Argidurids) Stumble, Delamar, east and Indian ricegrass and galleta. In the western 2/3 on lower alluvial occurs in Railroad Valley. Historic gold and silver mining. Today, military 80j. Semiarid 3151 Hills, low- and mid-elevation mountain slopes, 5800-9700/ Quaternary colluvium. Tertiary andesite, Mollisols (Argixerolls, Cleavage, Hapgood, Frigid, Cryic, 12-18 50-100 16/35; Mostly juniper steppe woodland and sagebrush steppe/ Mostly Woodland, mixed shrubland and grassland, rangeland, recreation, and wildlife limestone and dolomite; Silurian dolomite. Monte Cristo, Alko, south. slopes: Bailey greasewood and Shockley wolfberry are widespread reservations and active gold, silver, clay, sand, gravel, limestone, and decorative Uplands volcanic cones, and buttes. Moderate- to high- 400-3700 basalt, rhyolite, and tuff. Cretaceous Haplocryolls, Sumine, Ninemile, Mesic/ 48/80 mountain big sagebrush, low sagebrush, and grasses such as habitat. Cold water fi sheries occur; threatened bull trout are found in the Jarbidge Ordovician limestone, dolomite, shale, Nuyobe, Gabbvally, and often codominate. In east and south: warm desert species stone mining operations occur in Esmeralda County. gradient, perennial, intermittent, or ephemeral granitics. Jurassic shale, siltstone, Argicryolls, Softscrabble, Aridic Idaho fescue, cheatgrass, Sandberg bluegrass, Nevada bluegrass, River watershed and limited numbers of Lahontan cutthroat trout are found in a few quartzite, and volcanic rocks. Jolan, Yomba, Oricto, including blackbrush, Joshua tree, banana yucca, and cholla cactus. streams occur. Riffl e segments often have cobble sandstone, and carbonates. Upper Paleozoic Haploxerolls), Aridisols Linkup, Chad, bordering on bluebunch wheatgrass, Great Basin wildrye, bottlebrush drainages in the Santa Rosa Range east of McDermitt as well as in streams further Stewval, Handpah Saline bottoms: black greasewood. substrates. carbonates and shale. Permian chert, (Haplargids) Glean, Shalcleav, Xeric, Xeric squirreltail, and Thurber needlegrass; also serviceberry, snowberry, to the west. Water quality has been lightly- to moderately-degraded by human argillite, and shale. Silurian limestone and Hackwood, Parkay, and mountain-mahogany. In protected snow pockets: aspen activities. Historic gold mining south of Mountain City. Extensive gold mining 13v. Tonopah 2995 Foothills, hills, mesas, fans, and low mountains. 4600-8000/ Quaternary colluvium and alluvium. Aridisols (Haplargids, Armespan, Stewval, Mostly 8-12. 90-180 16/48; Great Basin sagebrush community/ Mostly Wyoming big sagebrush Shrubland, rangeland, wildlife habitat, and military reservations. Grazing has limy siltstone. Ordovician volcanics, shale, Cavanaugh, Tusel and chokecherry. Riparian areas: willows and chokecherry. operations continue, especially in the mountains near Jarbidge and Tuscarora. Sagebrush Ephemeral washes are common. Surface water 400-3000 Tertiary andesite, basalt, rhyolite, and Argidurids, Gabbvally, Zadvar, Mesic/ Available 56/96 and black sagebrush; also shadscale, blackbrush, spiny hopsage, affected sagebrush communities by reducing native grasses and biological soil crusts. chert, and limestone. Rock outcrops occur. Northwestern Nevada: western juniper woodland elements occur at comes from springs and sporadic foothill tuffs. Jurassic granitic rocks. Mississippian Haplocalcids), Entisols Breko, Entero, Aridic summer cliffrose, littleleaf horsebrush, littleleaf rabbitbrush, bottlebrush Rangeland has a low carrying capacity for cattle. Historic gold and silver mining. mid-elevations. Foothills precipitation events but is generally scarce. shale, siltstone, sandstone, conglomerate, (Torriorthents) Armoine, Lomoine, bordering on moisture squirreltail, Nevada ephedra, desert needlegrass, Indian ricegrass, Active gold, silver, and clay mining operations are found in Esmeralda County and and limestone. Devonian carbonates. Whilphang, Handpah Xeric, Aridic increases galleta, and scattered juniper. In the south and east: Mojave Desert Lincoln County. 80k. Partly Forested 105 Partially glaciated. High, rugged mountains with 8000-10900/ Quaternary colluvial and morainal deposits. Inceptisols Longhike, Jarbidge, Cryic, Frigid/ 16-26 Less than 14/31; Great Basin pine forest community/ Subalpine fi r, scattered limber Forest, brushland, shrubland, rangeland, forestland, wildlife habitat, and recreation. Ordovician carbonates, shale, and quartzite. toward the plants become more common and include yucca species (e.g. Mountains glacial features including moraines, cirques, 600-2900 Tertiary rhyolitic and andesitic rocks. (Eutrocryepts), Tusel, Hackwood, Xeric, Aridic 30-80 44/71 pine, and aspen groves. Near tree line, whitebark pine. Understory: Historic gold mining; exploration continues. Streams in the Jarbidge Mountains near Cambrian shale, quartzite, and limestone. east and Joshua tree). Basalt fl ows: spiny menodora. and tarns. Perennial or intermittent, high- Upper Paleozoic limestone and dolomite. Mollisols (Argicryolls, Foxmount, Layview, bordering on low juniper, mountain big sagebrush, serviceberry, snowberry, Jarbidge support the federally-threatened bull trout. Precambrian phyllite. Rock outcrops occur. south. gradient, cold streams are fed by snow-melt and Cambrian quartzite, limestone, and Haplocryolls, Segura, Hapgood Xeric mountain-mahogany, Idaho fescue, mountain brome, and Sandberg springs. Riffl e segments have cobble or boulder dolomite. Rock outcrops occur. Argixerolls) bluegrass. Highest elevations: some alpine tundra and meadows on 13w. Tonopah 789 Mountains and hills drained by ephemeral 6000- Quaternary colluvium and alluvium. Mollisols (Argixerolls, Powment, Lazan, Mesic, Frigid, 11-18 50-120 18/42; Juniper–pinyon woodland/ Mostly singleleaf pinyon and Utah Woodland, shrubland, rangeland, wildlife habitat, military reservations, and mining. substrates. poorly drained sites. Uplands washes. Surface water comes from infrequent 9500; most Tertiary andesite, rhyolite, and tuffs. Haploxerolls, Cucamungo, Cryic/ 53/85 juniper with an understory of mountain big sagebrush, Wyoming Historic gold and silver mining. precipitation events and scattered springs but is mountain Cretaceous granitics. Jurassic granitics, Palexerolls, Bellehelen, Aridic big sagebrush, desert bitterbrush, low sagebrush, snowberry, green 80l. Salt Shrub 355 Nearly fl at to gently sloping, internally drained 4200-5200/ Quaternary alluvium, loess, and playa, Inceptisols Wendane, Valmy, Mesic/ 6-10 100-130 18/40; Saltbush–greasewood and sagebrush steppe/ Black greasewood, Mixed shrubland and grassland, rangeland, wildlife habitat, and irrigated cropland generally scarce. summits: conglomerate, sandstone, and tuff. Triassic Haplocryolls), Entisols Nupart, Mohocken, bordering on ephedra, bottlebrush squirreltail, bluegrass, lupine, and prairie Valleys basins fl anked by alluvial fans and bajadas. Less than lacustrine, marsh, and landslide deposits. (Halaquepts), Entisols Delvada, Tenabo, Aridic, Aridic 51/89 rubber rabbitbrush, inland saltgrass, alkali sacaton, shadscale, bud growing alfalfa and small grains. Water diversions for livestock and cropland are 8000-9500/ limestone. Upper Paleozoic chert, argillite, (Xerorthents) Ravenswood, Brier, Xeric junegrass. In the south and east: interior chaparral components such Contains terraces, dunes, wetlands, hot springs, 50-600 Once inundated by Pleistocene pluvial (Torriorthents), Dugchip, Orovada, bordering on sagebrush, rushes, Great Basin wildrye, bottlebrush squirreltail, common. 400-2600 and shale. Mississippian shale, siltstone, Foxvire as Gambel oak. High elevations: scattered white fi r, limber pine, barren playas, and a few hills. Basin fl oors are lakes. Hills: Tertiary tuffaceous sedimentary Mollisols Knott. Very saline Xeric and cheatgrass. On alluvial fans and hills: Wyoming big sagebrush, sandstone, conglomerate, and limestone. and bristlecone pine occur but are extremely rare. often poorly drained, have a high water table, rocks and rhyolitic rocks. (Endoaquolls), and alkaline soils are spiny hopsage, rabbitbrush, Thurber needlegrass, Indian ricegrass, Devonian carbonates. Ordovician shale and pond water in the spring. Levels of its Aridisols (Natridurids, common. Sandberg bluegrass, and bottlebrush squirreltail. and chert. Cambrian shale, carbonates, and intermittent lakes vary seasonally and from year- Haplocambids) quartzite. Rock outcrops occur. to-year. Ephemeral and perennial streams occur.

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