Step 1: Characterize the Watershed

Purpose

To identify the dominant physical, biological, and human processes and features of the watershed that affect ecosystem function or condition.

To relate these features and processes with those occurring in the river basin or province.

To provide the watershed context for identifying elements that need to be addressed in the analysis.

To identify, map, and describe the most important land allocations, plan objectives, and regulatory constraints that influence resource management in the watershed.

Core Topics and Questions

Soil Resources ¾ What is the hierarchy of ecological units in the watershed, and what is the spatial relationship of these units? What are the inherent stability and erosion processes?

The Blue Creek watershed is located within the Dry Domain of the Temperate Steppe Regime Mountains Division of the Southern Rocky Mountain Steppe-Open Woodland-Coniferous Forest Province of the Overthrust Mountains Section of the Centennial Mountains and Island Park Subsection, outlined in the National Hierarchical Framework for Ecological Units (USDA Forest Service 1994). Descriptions of these different levels of ecological units are found in “Targhee National Forest Subsections and Landtype Associations” (USDA-FS 1998). There are three landtype associations nested within the Centennial Mountains and Island Park Subsections. These are identified as Beaverhead and Centennial Mountains- Conifer Forest, Island Park Plains and Falls River Tablelands-Conifer Forest, and Figure 1 Blue Creek Watershed vicinity map. Island Park Tablelands-Conifer Forest. Figure 1 shows the watershed boundary overlain by the Subsections.

Blue Creek Watershed Analysis 4 Physiography The landforms within the watershed consist mainly of caldera floor and scarp, dissected tablelands, foothills, and mountain slopes. Elevation ranges from 9,800 feet at the summit of Sawtell Mountain to 6,200 feet at the mouth of Henrys Fork. Slopes range from nearly level in riparian areas to over seventy percent on mountain sideslopes. Drainage patterns are dendritic with slight to moderate dissections. Some drainages are structurally controlled by bedrock. Aspects are generally southeast and southwest because of the trending slopes of the Island Park Caldera toward the Henrys Fork and the large mountains in the northwest corner of the watershed that form the Centennial Range (Hamilton 1965).

Geology Geological information for the watershed was collected from several publications and maps (Mitchel et al. 1979; Hamilton 1965; and Ross et al. 1967). The Island Park Caldera is an elliptical collapsed structure in the center of a rhyolite shield. Surficial geology in the watershed consists mainly of volcanic rocks of welded rhyolite tuff, basalt flows, and flows from the Madison and Pitchstone Plateaus of the Yellowstone Plateau. The rim of the caldera is the remnant of a broad shield of rhyolite in which ash flows predominate over ash falls and lava flows. Primary geologic formations, identified by the Idaho Department of Lands, Bureau of Mines and Geology, which formed the caldera and rim are post-caldera rhyolite ash flows and olivine basalt. The age of these geologic materials are Quaternary and Tertiary. Many ridges and mountain sideslopes in this watershed have exposed volcanic bedrock. Approximately 11,000 acres (20%) in the watershed have the potential for mass instability; however, no landslides have been mapped.

Ecological Units and Soils This watershed has few areas that have unstable landforms that show active landslides (USDA-FS 1997a). For the purposes of this characterization, three major landform groupings 1.) mountains and foothills, 2.) caldera floors and dissected tablelands/basalt plains, and 3.) terraces, outwash plains and floodplains are discussed. This is followed by a more detailed description of the 6 main ecological landtypes (of the 23 mapped in the area). Soils that formed from the geologic parent materials listed above have base saturation that provides relatively high natural fertility. Because many of the soils in this watershed formed from geology containing rhyolite and basalt, they have a dominance of sand and gravel in the profile. Clayey soils are usually associated with alluvial landforms. These kinds of soils have high erosion potential and may produce high levels of sediment when erosive conditions occur. Following in Figure 2 is an Ecological Unit map of the watershed including a table containing acres of each ecological unit on National Forest System lands. No information is shown for private land.

Blue Creek Watershed Analysis 5

Figure 2 Ecological Unit map of the Blue Creek Watershed.

Ecological Units on Mountains and Foothills On the National Forestland in the watershed, mountain and foothill landforms make up approximately 27,500 acres (47%). Soils that formed on the mountains and ridges are moderately deep to very deep (20”->60”) with some rock outcrop located on the steeper mountain sides. They are mainly Rhylow, Fitzwill, Edgway, Cryumbrepts, Yodal and Koffgo soils. Although these soils formed on steeper landforms, they have moderate to low erosion potential and have soil loss tolerance levels ranging from 2 to 5 tons per acre per year. They have higher potential to erode when they lose their protective ground cover. The potential is highest for mass movement on these landforms when soils become saturated with water.

Ecological Units on Caldera floors and Dissected Tablelands/Basalt Plains Soils that formed on the caldera floor and dissected tablelands/basalt plains are generally moderately deep to very deep (20 to >60”) and are well drained. They are dominantly vegetated with conifers, big sagebrush, aspen and mountain shrubs. These soils have less potential to erode than those formed on the mountains and ridges because they formed on slopes less than 40 percent. Maintenance of ground cover on these soils is important to maintain stable conditions. They have high range productivity potential and support a variety of uses including grazing, recreation and wildlife habitat. Compaction of these

Blue Creek Watershed Analysis 6 soils occurs when areas are used heavily from dispersed recreation, grazing and off-road vehicle use. Erosion from roads in this area is notable because ruts are often formed from vehicles when they are wet and channel sediment into the streams. Road maintenance is often required to reduce these impacts.

Ecological Units on Terraces, Outwash Plains and Floodplains Soils that formed on terraces, outwash plains and floodplains are the most productive in the watershed. They are almost always very deep (>60”) and are influenced by wetness during some period of the year. Riparian vegetation such as willows and sedges grow in most of the riparian soils. Soils on terraces may be affected by grazing livestock and wildlife, recreation, roads and influences from upland conditions. Some areas are susceptible to down-cutting which often lowers the water table. When this occurs, riparian vegetation is gradually replaced by upland species such as sagebrush. Most riparian soils appear to be in a productive condition in the watershed but some gully erosion and trampling in riparian areas has been observed.

Hydrology ¾ What are the dominant hydrologic characteristics and other notable hydrologic features and processes in the watershed? ¾ What are the basic morphological characteristics of stream valleys and segments and the general sediment transport and deposition processes in the watershed?

The Blue Creek Watershed is a 58,492 acre watershed, located within the Henrys Fork basin, between Henrys Lake and Island Park Reservoir. Henrys Fork basin extends from the Idaho border to the Henrys Fork confluence with the South Fork Snake River, north of Idaho Falls, encompassing about 3220 square miles. Average river outflow is about 2,100 cubic feet per second, or about 1,407,000 acre feet per year (Idaho Water Resource Board 1992).

Landscape Characteristics: Ecological Landtype Units The physical features of each sub-watershed have been described by the Targhee National Forest Ecological Unit Inventory (USFS 1999) (see Soils section). Each Ecological Unit (EU) is described by drainage patterns, physiography, soils and climate. Within the assessment area, there are six Ecological Units. These Ecological Units are:

1316 – This EU is delineated from Sawtell peak north and west. It is the extremely steep topography on and directly adjacent to the peak. The EU consists of glacial troughs, cirques and on the north side of topographically dominating peaks and ridges. Very steep slopes support open canopy mixed conifer forests that are frequently dissected by avalanche chutes, rock outcrops and rubble land. The soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. The soils are within hydrologic groups B and C, which means they have a moderate to slow infiltration rate when thoroughly wet and have a moderate to slow rate of water transmission through the soil

Blue Creek Watershed Analysis 7 profile. This would result in moderate amounts of runoff from snowmelt and precipitation events. Annual precipitation averages 32 inches.

1270 – This EU is delineated from Sawtell Peak south and east. Within this unit are the Yale headwaters, East Fork Hotel headwaters, Arrange Creek headwaters, West Fork Hotel Creek headwaters, and east slope Blue Creek headwaters. The EU is a transitional area between the forested and alpine zones. The landscape is characterized by steep (25%-60%), droughty, south facing sideslopes that support mixed conifers. They are lightly to strongly dissected by low spur ridges, shallow drainages and irregular bedrock controlled benches. The geology is igneous. Soils are generally moderately deep (20-40 inches) and well drained. The soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. Soils within the EU are within Hydrologic Group C, which have a relative slow infiltration rate when thoroughly wet. They may have a layer that impedes the downward movement of water or have soils having a fine texture. These soils have a slow rate of water transmission and can result in flashy runoff events from snowmelt or summer storms.

1315 – This EU covers the mid-sections of East Fork Hotel Creek, Yale Creek, White Elephant, and North, Middle and South Sawtell Creeks, and upper Bootjack Creek. It consists of mixed geology, mostly foothills and mountains in the warm portion of the forested zone. The topography is hilly slopes that are lightly to moderately dissected by incised drainageways. Drainageways have dry, south facing and moist, north facing sideslopes. Summits between drainageways support forests with variable canopy cover of mixed conifers and aspen. Dominant soils are generally very deep (60 inches +) and well drained. Slopes have a moderate potential for mass movement. The soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. The soils are within hydrologic groups B and C, which means they have a moderate to slow infiltration rate when thoroughly wet and have a moderate to slow rate of water transmission through the soil profile. This would result in moderate amounts of runoff from snowmelt and precipitation events.

1150 – This EU contains lower Yale Creek, White Elephant and Sawtell Creeks, and most of Coffee Pot and Tyler Creeks. It consists of foothills and mountains in the cool portion of the forested zone. The topography is characterized by south facing dipslopes (15%- 50%) that are moderately or strongly dissected by parallel drainageways. Closed canopy forests and reforesting clearcuts are common. Dominate soils are very deep (>60”) and well drained. The soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. Soils within this EU are in Hydrologic Group B. This means the soils have a moderate infiltration rate when thoroughly wet and a moderate rate of water transmission. This results in a moderate runoff rate from snowmelt and summer precipitation events.

Blue Creek Watershed Analysis 8 1149 – This EU covers most of Bootjack Creek and lower Hope Creek. It is mostly on unstable foothills and mountains in the cool portion of the forested zone. Land characteristics are characterized by concave sideslopes (15%-40%) that support forests of mixed conifers and aspen. The sideslopes are lightly dissected by low spur ridges, shallow draws, subtle benches and short, steep escarpments. Mass movements are common in some areas. Seeps and intermittent streams are common in draws and lower slope positions. Soils are generally very deep (>60”) and well drained. The soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. Soils within this EU are in Hydrologic Group B. This means the soils have a moderate infiltration rate when thoroughly wet and a moderate rate of water transmission. This results in a moderate runoff rate from snowmelt and summer precipitation events.

1594 – This EU is mostly within the Upper Hope Creek drainage. It consists of foothills and mountains, dissected table lands and escarpments of plateaus in the cool portion of the forested zone. The landscape is characterized by steep (30%-60%), north facing sideslopes that are lightly to moderately dissected by low spur ridges and shallow draws. They support reforesting clearcuts and closed canopy forests. However, the soils erode and compact easily when disturbed, which could result in moderate to high rates of erosion and sediment delivered to stream channels from disturbed areas. Soils within this EU are in Hydrologic Group B, which means the soils have a moderate infiltration rate when thoroughly wet and a moderate rate of water transmission. This results in a moderate runoff rate from snowmelt and summer precipitation events.

Climate Climate plays basic role in determining the form and function of a watershed. The kind, amount, and timing of precipitation in a watershed drives a variety of physical and hydrologic characteristics including topographical dissection (the density and spacing of stream channels), channel types and size and the amount and duration of runoff as streamflow.

Data Sources/ gaps ¾ USDA Forest Service RockClime ¾ NRCS SNOTEL – White Elephant site (http://www.wcc.nrcs.usda.gov/cgibin/site-wygraph-multi.pl?state=ID) ¾ Dusek, Gary L. Ed.-in-Chief. 2000. Aquatic Resources of the Henrys Fork ¾ Lack of climate stations on other portions of the watershed are data gaps.

Assumptions ¾ The Island Park and White Elephant sites represent average conditions within the analysis area.

The climate of the Henrys Fork watershed is arid to semi-arid, except at the highest elevations, and is characterized by subfreezing winters and cool summers. Mean annual

Blue Creek Watershed Analysis 9 temperature and precipitation, respectively, range from about 5.3 deg. C (42 deg F.) and 30 cm (12 inches) at the lowest elevations to less than 1 deg. C (32 deg. F) and over 100 cm (39 inches) at the highest elevations. Precipitation is uniformly distributed over the year at the lowest elevations but is characterized by large snowpacks during the winter months at the higher elevations. The vast majority of discharge in the Blue Creek watershed’s streams is derived from snowfall at the higher elevations. Stream hydrographs are dominated by high snowmelt flows during the spring and low base flows during the late summer and winter. At Island Park, located just south of the Blue Creek watershed, the mean annual temperature is 2.8 deg. C (37 deg. F). The mean annual precipitation is 74.8 cm (29.4 inches) (Dusek 2000).

Table 1 Climate parameters for ISLAND PARK DAM ID 44.42oN 111.40oW; 6300 feet elevation 56 years of record. Mean Mean Mean Maximum Minimum Number Month Precipitation Temperature Temperature of wet days (in) (oF) (oF) January 25.8 3.0 3.51 13.5 February 31.4 5.3 3.00 11.1 March 37.9 9.3 2.62 10.5 April 48.1 20.9 1.84 8.0 May 59.6 30.8 2.13 8.9 June 68.8 37.6 2.43 9.3 July 78.6 42.9 1.16 6.1 August 77.7 40.8 1.32 6.3 September 67.9 32.9 1.57 6.3 October 55.0 25.2 1.75 6.7 November 36.7 14.8 2.52 9.7 December 27.4 5.9 3.35 12.4 Annual 27.19 108.8

Rock:Clime 'describe climate parameters' version 2003.04.24 USDA Forest Service, Rocky Mountain Research Station

As stated above, the hydrographs of area streams are typical of snowpack-dominated hydrologic regimes. The depth of snow, and particularly the timing and duration of snowmelt have a profound influence on the type, size and condition of the area streams, as well as how the watershed responds to disturbances, such as timber harvesting and

Blue Creek Watershed Analysis 10 grazing. The following graph (Table 2) depicts the snow-water equivalent at the White Elephant SNOWTEL site located near Sawtell Peak along FDR 024. The long-term average has snow accumulations starting in mid-October, ending in mid-June. Average peak accumulations occur in mid-April, with about 90 inches of snow, and a water equivalent of about 30 inches. Snowmelt is relatively rapid, occurring over a two month period from late-April to mid-June. In 2003, considered a drought year, maximum snowpack occurred in early May (72 inches of snow with a water equivalent of only 24 inches). Snowmelt was extremely rapid, lasting only about three weeks. In 2004, snow season snow water equivalent and precipitation represented average conditions.

Table 2 Average Snow Depth and Water Equivalent 2003 and 2004

Blue Creek Watershed Analysis 11

In addition to the measured climate date, above, the National Oceanic and Atmospheric Administration (NOAA)/National Weather Service has calculated precipitation events of varying intensities. These are used to calculate runoff from varying storm events. Below are calculations for four storm events ( Table 3).

Table 3 Precipitation Frequency Data Output NOAA Atlas 2 Idaho 44.55ºN 111.25ºW Site-specific Estimates. Hydrometeorological Design Studies Center - NOAA/National Weather Service 1325 East-West Highway - Silver Spring, MD 20910 - (301) 713-1669 Map Precipitation (inches) Precipitation Intensity (in/hr) 2-year 6-hour 0.81 0.13 2-year 24-hour 1.36 0.06 100-year 6-hour 1.81 0.30 100-year 24-hour 2.80 0.12

Streamflows and Hydrographs

Data Sources/gaps ¾ USGS Streamflow stations ¾ Lack of gauging stations on individual streams is a data gap

Assumptions ¾ Streamflow data within Henrys Fork represents general runoff characteristics of the watersheds within the analysis area.

There are no stream gauges, either current or historical, on any of the streams within the analysis area. Area stream hydrographs are typical of snowpack-dominated regions. That is, they have relatively low base flows during the late summer and winter periods, with high peak flows during the spring snowmelt period. Streams within the assessment area must carry as much as 30 inches of water equivalent that melts during a two month period during the spring. A stream may see peak snowmelt runoff flows several orders of magnitude greater than base flows. Henrys Fork has been gauged at several locations throughout the system since the early 1900’s. These are: 13039000 – Henrys Lake near Lake, ID; 13039500 – Henrys Fork near Lake, ID; 13041010 – Henrys Fork below Coffee Pot Rapids near Macks Inn, ID; 13042500 – Henrys Fork near Island Park, ID; 13046000 – Henrys Fork near Ashton, ID; 13050500 – Henrys Fork at St. Anthony, ID; and 13056500 – Henrys Fork near Rexburg, ID.

Table 4 summarizes the maximum, minimum, average streamflows for the various gauging stations, as well as the calculated average annual acre foot per square mile for the watershed above each station.

Blue Creek Watershed Analysis 12

Table 4 Streamflows by USGS Station Station Maximum Minimum Average Acre Remarks Name/ Discharge Discharge Discharge feet/sq Number mi.

13039500 – 907 cfs 0 cfs 54 cfs 392 Flows regulated by Henrys June 13, Sept. Henrys Lake 0.2 mi Fork near 1926 1952, upstream Lake, ID 1966 and 1977 13041010 – 2,240 cfs 246 cfs 486 cfs 1,349 Flows partly Henrys May 9, 1997 July 31, regulated by Henrys Fork below 2002 Lake, 16.4 mi Coffee Pot upstream Rapids near Macks Inn, ID 13042500 – 3,030 cfs cfs 627 cfs 944 Flows regulated by Henrys May 23, Nov-Dec, Henrys Lake and Fork near 1984 1938 Island Park dam. Island Park, Diversions above ID station for 15,500 ac of irrigation. 13046000 – 8,140 cfs 53 cfs 1,536 cfs 1070 Flows highly Henrys May 15, Sept 20, regulated by Fork near 1984 1960 reservoirs and Ashton, ID irrigation 13050500 – 13,200 cfs 21 cfs 1,975 cfs 808 Flows highly Henrys May 16, July 9, regulated by Fork at St. 1984 1973 reservoirs and Anthony, irrigation ID 13056500 – 79,000 183 cfs 2,112 cfs 523 Flows highly Henrys June 5, 1976 March, regulated by Fork near (Teton Dam 1934 reservoirs and Rexburg, failure) irrigation ID 16400 May 17, 1984

Blue Creek Watershed Analysis 13 Table 5 summarizes the monthly mean streamflows for the gauge below Coffee Pot rapids, near Macks Inn. The gauge is a new site starting in October 1995, therefore long- term data are not available. Peak flows occur in May. This is slightly before the peak portion of the snowmelt from the analysis area, and reflects the melting snowpack from the lower areas within the watershed, outside the analysis area.

Fremont County, Idaho Hydrologic Unit Code 17040202 Latitude 44°29’00”, Longitude 111°23’37” NAD27 Drainage area 261 square miles Contributing drainage area 261 square miles

Table 5 USGS 13041010 HENRYS FORK BLW COFFEE POT RAPIDS NR MACKS INN ID Period of Record – Oct. 1995 – Present Monthly mean streamflow, in ft3/s YEAR Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

1995 486 464 475 1996 426 376 331 485 1,017 747 495 469 456 448 460 431 1997 490 512 523 619 1,162 851 605 547 547 544 510 494 1998 507 492 467 528 964 753 598 473 455 431 439 424 1999 425 445 454 501 1,008 907 570 500 497 475 459 453 2000 474 472 454 677 610 510 426 384 369 375 355 345 2001 341 340 334 443 404 482 496 431 291 294 285 279 2002 276 266 260 328 444 333 272 271 285 Mean of monthly 420 415 403 512 801 655 495 439 414 436 425 414 streamflows 0.66 nadww01

Table 6 depicts the annual peak flows at Henrys Fork near Island Park. This station is located about 9 miles below the Coffee Pot site. As the Coffee Pot site, above, peak runoff flows occur in May thru June. However, due to flow regulation from Island Park Dam and Henrys Lake, regulated peak flows normally occur within the channel during July and August.

Blue Creek Watershed Analysis 14 Table 6 Annual Maximum Instantaneous Peak Flows, Henrys Fork near Island Park

The lowest peak flow at the Henrys Fork station near Island Park was recorded in 1935 at about 800 cubic feet per second (cfs). During November-December 1938, the lowest instantaneous flows were recorded at 1.0 cfs. The highest peak flow was recorded in 1984 at slightly over 3000 cfs. Average peak flow is in the neighborhood of 2000 cfs. Peak flows in 2001-3 were all below average, ranging from about 1300 cfs to about 1700 cfs.

Vegetation ¾ What is the array and landscape pattern of plant communities and seral stages in the watershed? What processes contribute to these patterns?

Data Source/Assumptions To determine the distribution of cover types within the assessment area, the 1992 Targhee National Forest vegetation GIS data layer was used. This data layer was compiled from a variety of sources such as compartment exams and Landsat imagery data. Approximately 42,955 acres or 73% of the assessment area is classified as forested (Table 7).

Blue Creek Watershed Analysis 15 Table 7 Distribution of Vegetation Cover Types Vegetation Type Acres % FOREST 42955 73% NONFOREST 15307 26% UNKNOWN 231 <1% TOTAL 58493 100%

Of these forested acres, 37,222 or 87% is on National Forest System lands (Table 8). Since there is more detailed forest cover type and structural information available on these lands, the forested vegetation assessment will only address National Forest System lands.

Table 8 Distribution of Forested Acres by Ownership in the Blue Creek Assessment Area Ownership Acres % Forest Service 37222 87% Private 3396 8% Bureau of Land 1198 3% Management State 1138 3% TOTAL 42955 100%

Data Gaps There are several data gaps within the assessment area for forested vegetation. They are:

¾ Limited information and lack of a complete inventory of old growth and late seral forest within the assessment area.

¾ Majority of the stand exam information is 15-20 years old.

¾ Lack of detailed mapping of minor and high risk cover types such as whitebark pine and aspen.

Forest Cover Type Overview Forest cover type distribution within the assessment area has been influenced by historical management, disturbance, and forest succession. Lodgepole pine (Pinus contorta) dominates the assessment area (Figure 3). This cover type is predominantly found in lower elevations of the assessment area. The other forest cover types have been broken into categories; however, most of the landscape can be considered a mix of Douglas-fir (Pseudotsuga menziesii), quaking aspen (Populus tremuloides), and subalpine fir (Abies lasiocarpa). At the highest elevations, and in minor amounts, whitebark pine (Pinus albicaulis) and Engelmann spruce (Picea engelmannii) can be found (see Table 9).

Blue Creek Watershed Analysis 16

Figure 3 Forest Cover Types for the Blue Creek Assessment Area.

Blue Creek Watershed Analysis 17 Table 9 Distribution of Forest Cover Types in the Blue Creek Assessment Area

Forest Cover Types 4% <1% <1% 13% LODGEPOLE DOUGLAS-FIR MIXED LP/DF 46% OTHER MIXED 19% SPRUCE/SUBALPINE FIR WHITEBARK PINE ASPEN 18%

Aquatic Species and Habitat ¾ What is the relative abundance and distribution of aquatic species of concern that are important in the watershed? What is the distribution and character of their habitats?

Mountain whitefish and Yellowstone cutthroat trout are the only native salmonid species that occurred in these streams. The Regional Forester has designated Yellowstone cutthroat as a sensitive species. The US Fish and Wildlife Service is currently being sued to list the Yellowstone cutthroat under the Endangered Species Act. Within the analysis area, recent stream surveys by the Caribou–Targhee National Forest reported no cutthroat. Two streams are tributaries to Henrys Lake, which supports a large population of adfluvial (lake dwelling) cutthroat. Past and current actions in the analysis area include fish eradication projects, stocking of non-native trout, dams and irrigation diversions, flow alterations, grazing, vegetation management, roads, dispersed camping, authorized trails, unauthorized ATV trails, and adjacent subdivision development. These activities have affected the ability of cutthroat to survive or compete.

The Blue Creek Watershed contains streams that are tributaries to Island Park Reservoir, upper Henrys Fork, and Henrys Lake. There are 13 perennial tributaries known to contain fish, and one tributary that contained fish as recently as 2002, but apparently these fish have succumbed to the drought and low flows.

Fish known to be native to the area and likely occurring in the analysis area at one time, if not currently, are the Yellowstone cutthroat (Oncorhynchus clarki bouvieri), mountain whitefish (Prosopium williamsoni), mottled sculpin (Cottus bairdi), redside shiner (Richardsonius balteatus), mountain sucker (catostomus platyrhynchus) speckled dace (Rhinichthys osculus), and the longnose dace (Rhinichthys cataracate). The following introduced species are known to occur: brook trout (Salvelinus fontinalis), rainbow trout (Oncorhynchus mykiss) Utah chub (Gila atraria), and Utah sucker (Catostomus ardens).

Blue Creek Watershed Analysis 18

The primary cause of the extirpation in small streams of Yellowstone cutthroat is thought to be direct competition and predation by the highly piscivorous (fish eating) introduced brook trout. Rainbow trout also pose a threat of hybridization and dilution of the cutthroat genes. Since no hybrids were found in stream surveys it is thought that brook trout are the main cause of the loss. Other management activities that had a profound effect on the Henrys Fork River are the repeated chemical treatments of Island Park Reservoir and the Henrys Fork to control Utah chub and whitefish, which removed the fluvial and adfluvial populations of cutthroat from the watershed. With the removal of the cutthroat population the source to re-found cutthroat populations was lost. Dewatering and degradation of habitat by irrigation flows also played a role in the removal of cutthroat.

Unauthorized motorized recreation trail building associated with adjacent subdivision development continues to threaten water quality and habitat. Some areas could benefit from improved management by the Forest Service.

It is difficult to re-establish meaningful populations of cutthroat due to issues of chemical treatments, re-colonization by non-natives, diversions, dewatering, and conflicts perceived and real with the famous sport fisheries of the area.

The effects from irrigation flows out of Henrys Lake Outlet and the resultant unstable channels and erosion have caused a major increase in sedimentation of the Henrys Fork. This is the major challenge facing the upper river.

Terrestrial Species and Habitat ¾ What is the relative abundance and distribution of species of concern that are important in the watershed? What is the distribution and character of their habitats?

Threatened and endangered species that may occur in the Blue Creek watershed are Bald eagles, wolves, grizzly bears and possibly lynx.

The Blue Creek watershed is within the Yellowstone nonessential experimental population area of the Gray Wolf (Canus lupus). The Northern Rocky Mountain wolf population is currently estimated at a minimum of 1300 animals.

Wolf Management Plans for Idaho and Montana have been completed and approved by USFWS. There have been track reports and observations of wolves in the Blue Creek

Blue Creek Watershed Analysis 19 watershed area since the late fall of 2003. These tracks were verified by Bryan Aber, District Wildlife Biologist, Ashton/Island Park Ranger District and by IDFG.

Canada Lynx (Lynx Canadensis) - the Blue Creek watershed area is considered Lynx habitat. Primary vegetative types (lynx habitat), as described in the Lynx Conservation Assessment Strategy (LCAS) (Ruediger et.al 2000) (USDI 2000) are patchy on the Targhee National Forest east of I-15 but may provide suitable lynx habitat. Most of the watershed area is considered suitable habitat to sustain a lynx population, regardless, it is important to retain cover and manage the area as a linkage corridor between LAU’s (Lynx Analysis Units). Blue Creek watershed is within LAU 4 and 5 as mapped by the Caribou-Targhee National Forest and approved by the US Fish and Wildlife Service in April 2005.

Grizzly Bear (Ursus arctos) habitat is a mixture of alpine tundra and subalpine mountain forests. In Idaho, grizzly bears occupy lodgepole pine/ Douglas-fir forest near Yellowstone National Park. Herbaceous matter dominates their diet, but they also eat carrion, mammals, fish, insects, and garbage. A Yellowstone area study found ungulate remains composed a major part of early season diet, graminoids dominate May- June, and Whitebark pine seeds were important in late season; berries composed a minor portion of scats in all seasons. (Groves et. al. 1997). The Blue Creek Watershed provides alpine meadows and subalpine forests with Whitebark pine as a component.

The Blue Creek Watershed also provides habitat for several Forest Service sensitive species including Wolverine (Gulo gulo), Boreal owl (Aegolius funereus), Great gray owl (Strix nebulosa), Northern goshawk (Accipiter gentilis), Three-toed woodpecker (Picoides tridactylus), and Spotted frog (Rana pretiosa). Sensitive species that do not exist because of lack of habitat include the spotted bat (Euderma maculatum), Townsend’s Big-eared bat (Corynorhinus townsendii), trumpeter swan Cygnus buccinator, common loon (Gavia immer), Harlequin duck (Histrionicus histrionicus), Peregrine falcon (Falco peregrinus), Columbian sharp-tailed grouse (Tympanuchus phasianellus), Flammulated owl (Otus flammeolus), and fisher (Martes pennanti), (Groves et. al. 1997, Spahr et.al 1991).

Other Species of interest The watershed provides year round habitat for whitetail deer, mule deer, elk and moose. No areas of the watershed are managed as winter range habitat; however whitetail deer, moose and occasionally a few elk winter along the Henrys Fork of the Snake River. Most ungulates migrate south to the Sand Creek winter range or north to the Madison River in Montana.

Range and Livestock ¾ What are the rangeland resources in the watershed, and what are the major livestock grazing activities that occur?

Blue Creek Watershed Analysis 20 There are 7 grazing allotments within the Blue Creek Watershed Analysis area (Figure 4). Namely; Blue Creek Sheep & Goat (S&G), Coffeepot S&G, Hotel Creek S&G, Icehouse/Willow S&G, Sawtell S&G, Bootjack Cattle & Horse (C&H), and Meadow View C&H allotments. Over the past decade there has been very little grazing activity within the watershed analysis area. Grazing has occurred on Bootjack (Meadow View) C&H, and the Icehouse/Willow S&G allotments. Approximately 33% of the Icehouse/Willow S&G Allotment is included in the analysis. All other allotments (sheep & goat) within the analysis area have been closed. This closure came through direction from the 1997 Revised Forest Plan for the Caribou-Targhee National Forest; specifically, Management Prescription 5.3.5 (Grizzly Bear Habitat). This management prescription places elevated emphasis upon a high degree of security and resource conditions which contribute toward the conservation and subsequent recovery of the grizzly bear (1997 Targhee RFP, lll-46-47). Because of this direction sheep allotments were, and continue to be closed on an opportunity basis (typically, as the permit expires).

Figure 4 Range Allotments within the analysis area.

Fire and Fuels ¾ What are the major fire regime condition classes (FRCC) that occur in the watershed?

¾ Where does the wildland/urban interface occur and what condition is it in?

Blue Creek Watershed Analysis 21

Increasing development on private land within the analysis area along the south boundary increases the probability of fire spreading between National Forest lands and private developments.

A district interdisciplinary team (IDT) conducted a Fire Regime Condition Class (FRCC) assessment for the Blue Creek Watershed and determined that the overall FRCC for the watershed is FRCC II (FRC classes defined in Figure 5 Description of FRCC condition classes (taken from USDA Forest Service, 2007).). That is a Fire Regime of III and a Condition Class of II. Within the watershed, most of the aspen is in a FRCC III, Douglas-fir and lodgepole pine is in FRCC II, and most of the higher elevation habitat types are in FRCC I. Whitebark Pine FRCC is higher due to influence of exotic disease, such as white pine blister rust, and insects such as the bark beetle.

Figure 5 Description of FRCC condition classes (taken from USDA Forest Service, 2007).

Conifer cover types have gained considerable acres from the aspen cover types through the process of vegetation succession over the past century. A high percentage of stands now dominated by Douglas-fir have either a minor component of residual aspen or skeletons of aspen in the form of down woody debris. Any evidence of aspen within a stand of conifer indicates that an aspen cover type once occupied that place in the landscape (Bartos and Campbell 1998).

Data from forest stand exams completed in the watershed (2002) indicate forest succession in the absence of fire is allowing dense, small-diameter stands of Douglas-fir

Blue Creek Watershed Analysis 22 to occupy sites where historically light-intensity fires would have reduced densities. Fire return intervals now average well over 100 years, with increasing susceptibility to stand replacement fires. Ladder fuels exist where plant succession has led to dense regeneration of Douglas-fir under existing canopies.

Fuel loadings are increasing due to high mortality of Douglas-fir from the recent bark beetle outbreak. Most of the hazardous fuel loading occurs in the high elevation subalpine fir habitat type, and in those stands with high mortality rate from beetle kill and other disturbances. Fuel loading in the watershed ranges from 3 ton/acre in the more open stands of timber to 30 ton/acre in the more decadent and insect infested stands.

Human Uses ¾ What are the major human uses and where do they generally occur in the watershed?

Recreation activities in the watershed include hunting, hiking, mountain biking, camping, sightseeing, fishing, firewood cutting, berry picking, motorized and non-motorized boating, and motorized use by ATV’s. The majority of the private land within the watershed has been developed into subdivisions. Commercial uses including outfitter and guides, ditch bill easements, communication site leases, County/State maintenance buildings and snowmobile trail grooming. All commercial uses on National Forest System lands are authorized through Special Use Permits.

The majority of the recreation use in the watershed occurs during the months of June, July, and August. Much of that recreation originates from vacation homes located in the Island Park area. National Forest System (NFS) lands share approximately eighteen miles of boundary with private land with the watershed area. There are 6 large subdivisions located along that boundary. In addition, there are private in holdings, within the NFS boundary, that will potentially be developed in the near future.

Dispersed camping occurs in Bootjack, Blue Creek, Stamp Meadows and Mill Creek areas. Most dispersed campers use Recreation Vehicle trailers (RV’s) often accompanied by ATV’s. The Mill Creek area is a very popular boating site on Island Park Reservoir. A boat ramp, floating docks, fire rings and a SST vault toilet are provided at that site. The area is also popular during the fall hunting season. It is an especially popular during archery season, primarily in the Sawtell, Bootjack and Blue Creek areas.

The watershed offers a profusion of snowmobiling opportunities. There are approximately 30 miles of groomed snowmobile trail within the watershed. The area is a popular off-trail destination for snowmobilers as well, although most of the more popular areas are located to the west of the watershed in the Centennial Mountains. Fremont County currently maintains plowed parking areas for snowmobilers at Blue Creek, Stamp Meadows (2) and Red Rocks Road.

Blue Creek Watershed Analysis 23 The five mile long Sawtell Peak trail is maintained as a hiking, horseback and mountain bike trail. There is an additional 6 miles of non-motorized trail located in the Rock Creek and Hope Creek drainages that are not currently being maintained. The Big Springs National Scenic Water Trail borders the southwest corner of the analysis area There are currently approximately 4000 acres open to cross-country motorized use, the remainder of the National Forest lands may only be traversed on the twenty-five miles of existing Forest roads. These areas are used extensively by ATV users.

There a number of commercial activities, authorized by Special Use Permit, within the watershed. Those activities are as follows:

Outfitter and Guide: Eagle Ridge Ranch - Day-use horse rides, wagon rides, and hunting Tom Angell - Day-use horse rides

Snowmobile Outfitters: Kevin Philips Three Bears Lodge Yellowstone Artic Cat/Yamaha Yellowstone Adventures Loomis Enterprises

BYU-Idaho - Hiking, Horse Rides, Mountain Biking

Communication Leases: Sawtell Communications Site

County/State/Federal Maintenance Buildings: Idaho Department of Transportation Maintenance Sheds FAA Storage Shed Fremont County Maintenance Sheds

Utility Easements: Cold Springs Sub-station Buried Telephone cable Power Transmission Lines

Blue Creek Watershed Analysis 24