The Middle Mountains extend from Oakley, Idaho at the north end towards the Idaho/Utah state line on the south. Goose Creek runs along the west side, and Junction Valley and the Albion Division are to the east. Much of the Middle Mountain area is BLM land. Parts of the mountains are state lands, and there are extensive private holdings on the east side of the range. See Figure M-1.

The Middle Mountain region and adjacent lands are part of the Western Basin and Range ecosystem subregion (Ecoregions of the United Sates, USDA Forest Service, 1994). At one time the Middle Mountain area was known as South Mountain. South Mountain was the name given by Alfred Anderson to the area in 1931; the names are still used interchangeably (Geology and Mineral Resources of Eastern Cassia County, Anderson, 1931). Elevations in the Middle Mountains range from 4,500 feet to over 8,000 feet. Many of the Middle Mountain valleys are glacial in origin. The Middle Mountains are a tilted block formation, made primarily of quartzites. Closer to Goose Creek the range surface is quartz latite volcanics that cap ash beds (Geology and Mineral Resources of Eastern Cassia County, Anderson, 1931).

Summers are generally quite dry. Average annual precipitation for Middle Mountain and adjacent lands is less than 12 inches per year (Geology and Mineral Resources of Eastern Cassia County, Anderson, 1931). Average annual temperatures range from daytime highs of 35 ⁰F or less in January to 90 ⁰F or more in July. Access is mainly limited to unimproved canyon roads from the west side. Higher elevations are generally inaccessible from the end of December through the middle of May.

The recreational values and uses of the Cotterel Mountains are mainly hunting, fishing, prospecting, and other related outdoor activities. Recreational fishing still occurs in the main Goose Creek, Cold Creek, Blue Hill Creek, and Little Birch Creek waters with varying success. Fisheries values have been limited by habitat conditions for a number of years. Public access is limited; most upper roads are accessible only by high-clearance or 4-wheel drive vehicles. Public access from the east side of Middle Mountain is blocked by large expanses of posted private land. Good access for most vehicles (in dry weather) can be obtained to lower Emery Creek and Little Birch Creek Canyons on the west side. Much of the north end of the Middle Mountains are currently under mining operations with limited or no public access allowed, depending on the location. Middle Mountain has no improved camping or other public recreational facilities.

The Middle Mountains and adjacent lands support a variety of plant communities. Sagebrush-steppe and shrub-steppe communities occupy much of the lower foothills as well as valleys and hillsides at higher elevations. Sagebrush communities include both Big Sagebrush and Low Sagebrush species (Sagebrush-Grass Types of Southern Idaho, Hironaka et al, 1983). Bitterbrush communities are common among upper rocky outcrops and along mesa edges.

Juniper woodlands are present over much of the mountain area, and include a small percentage of Pinyon Pine. Juniper cover ranges from scattered individuals to 75% and more in some locations. Isolated pockets of Douglas Fir and aspen exist on north facing slopes and in higher drainages. A wide variety of both native and introduced forbs (herbaceous plants) and grasses are present throughout these shrub and tree communities.

Rare plant values include the presence and potential for additional populations of Idaho Penstemon (Penstemon idahoensis) and Goose Creek Milkvetch (Astragalus anserinus). The exposed volcanic ash soils found in areas of the Middle Mountains are the soil type that hosts Idaho Penstemon. Known populations of these plants are located within the Goose Creek watershed (CDC Database, Idaho Department of Fish and Game, 1999). Other rare plant values of the Middle Mountain area include the sensitive plant Simpson's Hedgehog Cactus (Pediocactus simpsonii). Additional rare plant inventories have yet to be conducted in this region (Idaho Rare Plant Conference, Cheney, 2000).

Native vegetation has been altered in some of the region through past activities including prescribed burns and Crested Wheat-grass seedings. Rangelands at lower elevations, particularly in areas of controlled or natural burns, have been heavily invaded by Cheat Grass (Bromus tectoum) in recent years. Cheat Grass competes with perennial native grasses, and is common on overgrazed or disturbed rangelands (Weeds of the West, Whitson et al, 1999).

Watershed values of the Middle Mountain region and adjacent public lands are high. Despite limited precipitation, the region produces a lot of surface flow in the form of creeks and springs. Many drainages contain ephemeral and intermittent streams that run during wet years or after heavy precipitation events. A number of streams are perennial and sustain riparian and wildlife values. Remnant riparian vegetation in some drainages and at dry spring sites indicates that even more surface water may have been available in the past.

Aspen groves are a valuable watershed component (Aspen Community Types of the Intermountain Region, Mueggler, 1988) but are present in limited amounts. Wells have been drilled at some lower elevations to provide water sources for livestock. Historic springs in the region have been developed for livestock use and many no longer provide surface water at their original sites.

The Middle Mountains and adjacent lands support a wide variety of both game and non-game wildlife species. The waters of Goose Creek contain Leatherside Chub, an Idaho sensitive fish species. Perennial streams throughout the region are historic habitat for Yellowstone Cutthroat Trout (Idaho Department of Fish and Game, 2000). Rainbow, Brook Trout, and other species also inhabit the regions waters.

The Middle Mountains support Mule Deer, Elk, Mountain Lions, and many other mammals. Snowshoe Hares are present at higher elevations of the Middle Mountains. Idaho state sensitive species in the Middle Mountains include the Merriam's Shrew, Kit Fox, Pygmy Rabbits, and occasional Big-horned Sheep (CDC Database, Idaho Department of Fish and Game, 1999). The many rocky canyons are important bat roo sting sites and many locations are being actively used by a variety of species, including Pallid Bats (CDC Database, Idaho Department of Fish and Game, 1999). The Middle Mountains also contain suitable habitat for the Cliff Chipmunk, known in Idaho exclusively from Cassia County (Atlas of Idaho's Wildlife, Idaho Department of Fish and Game, 1997).

The Middle Mountains provide foraging and nesting habitat for many species of raptors including the Western Screech Owl, Sawhet Owl, Prairie Falcon, Golden Eagle, Northern Harrier, and Ferruginous Hawk. The Ferruginous Hawk is a state sensitive species, with active nest locations in the Middle Mountains (CDC Database, Idaho Department of Fish and Game, 1998). Western Burrowing Owls, also a state sensitive species, are successfully nesting at lower elevations of the range and along the foothills that extend out into the valleys. Other Idaho state sensitive bird species in the region include the Loggerhead Shrike, Least Goldfinch, Lark Bunting, and Pinyon Jay (CDC Database, Idaho Department of Fish and Game, 1999). Bobolinks have been found in the region (Idaho Department of Fish and Game, Ritter, 1996). Rocky cliffs and canyons, such as the Goose Creek Narrows are suitable habitat for the White-Throated Swift.

Many other species of birds also rely on the habitats provided by the Middle Mountains, including the Vesper Sparrow, Brewer's Sparrow, and Sage Grouse; all sagebrush obligates (Atlas of Idaho's Wildlife, Idaho Department of Fish and Game, 1997). Sage Grouse have active lek sites near Worthington Springs and on the lower northwest slopes (Idaho Department of Fish and Game, 2000).

The Middle Mountains provide habitat for a number of Idaho's reptile and amphibian species. Amphibians, both frogs and toads, are present at riparian and aquatic sites. The BLM feels that the area may still host some of the state's less common amphibians such as the Spotted Frog. The Middle Mountains host Idaho reptiles such as the Rubber Boa and Striped Whipsnake. The Middle Mountains contain suitable locations that may have been historical habitat for the uncommon or rare Longnose Snake (Rhinocheilus lecontei) as well as possible historical habitat for the Ringneck Snake (Idaho's Amphibians and Reptiles, Idaho Department of Fish and Game, 1994). Unconfirmed reports of Longnose Snakes exist for the Goose Creek area, south of the Cold Creek confluence.

Habitat conditions have profound short and long-term effects on which species are able to successfully use a location. Mammal and bird observations were recorded during the surveys performed at a variety of riparian locations in the Middle Mountain region. This data is included in Appendix F for the benefit of interested land managers or members of the public. The presence or non-presence of species, presence of habitat-generalists, and other clues provided by the frequency observations can aid in determining the health of a riparian system or identifying needed changes. Although short-term data is not definitive for these locations, it is indicative and has been made available as a management resource.

The Middle Mountains are currently being used for livestock grazing purposes. Livestock utilization of riparian habitat can lead to adverse impacts of vegetation, watershed, and wildlife values if proper guidelines and standards are not applied. A survey has been performed of representative seeps, springs, and riparian zones in the Middle Mountains and on adjacent lands in order to determine the condition of riparian habitats following the 1999 grazing season.

Each of the following summaries contains a short description of impacts, recommendations for action, and photographic documentation. The recommendations reflect current (year 2000) riparian recovery times recommended by the USDA Forest Service Intermountain Region and Rocky Mountain Research Station scientists.

*Wildlife frequency data originally preceeded the summary section. Due to the large volume of data collected and to avoid confusion, frequency charts are now located in Appendix F.