Cow Creek

Cow Creek covers 17,917 acres of arid prairie on the Thunder Basin National Grassland in northeastern Wyoming, where the eastern edge of the Powder River Basin spreads into a broad mosaic of grassland, sagebrush flat, and isolated ponderosa pine outcrops. The terrain is shallow and dissected rather than dramatic — Archie Draw and Coal Draw cut northward through the area as ephemeral channels, carrying spring runoff and summer thunderstorm flows down to the Lower Dry Creek headwaters. Owl Creek, Piney Creek, Middle Creek, and Deer Creek drain adjacent uplands and converge into the same prairie watershed. Water on this landscape is intermittent rather than perennial: it gathers in draws after storms, sustains shallow seeps in clay swales, and disappears between events into the sun-cracked soils below.

The vegetation reflects the slow climatic gradient that pulls the Great Plains westward into Intermountain country. Northern Great Plains Mixed Grass Prairie carpets the level uplands, dominated by cool-season bunchgrasses on the heavier loams. Where soils thin and salts rise, this gives way to Intermountain Saltbush Flats and Intermountain Greasewood Flat, characterized by low salt-tolerant shrubs on bare alkali ground. Great Basin Big Sagebrush Steppe and Great Basin Big Sagebrush Shrubland occupy the deeper, well-drained mid-slope soils, while Intermountain Mountain Sagebrush Steppe appears on higher benches. Black Hills Ponderosa Pine Woodland and Savanna forms scattered stands on rocky outcrops and north-facing slopes — small, isolated tree islands that serve as nesting and roosting habitat across an otherwise open landscape. Great Plains Sand Prairie holds the sandier substrates between draws. The result is a fine-grained patchwork in which a quarter mile of walking can carry a visitor from sage-dominated steppe across a saltbush flat, into the shade of a ponderosa stand, and back out onto open grass.

Portions of this area fall within the potential range of several federally listed species; see the Conservation section for details.

Moving through Cow Creek means moving across exposure. From a low rise above Archie Draw, the country reads as a long, open horizon broken by the dark crowns of scattered pine on the higher outcrops and the silver-gray of greasewood and saltbush on the alkali flats below. The air is dry; the wind is steady and audible. After a thunderstorm, the draws run loud and brown for a few hours before drying back to gravel, leaving cutbanks and small new alluvial fans where the gradient flattens. In the cool of early morning, the ponderosa islands give shade and a measurable drop in temperature, and at midday the sagebrush flats hold the heat and the smell of resin and dust. A walk down Coal Draw to its junction with Lower Dry Creek crosses every major ecosystem type in the area in a few miles, a working illustration of how slope, soil, salt, and aspect partition a flat-looking landscape into separate ecological neighborhoods.

The mixed-grass prairie of present-day Converse County, where the 17,917-acre Cow Creek Inventoried Roadless Area sits today, has been inhabited for thousands of years. Archaeologists unearthed huge bison bones from an arroyo trap on the Hawken Ranch south of Sundance, Wyoming, in the 1970s, and dated them to more than 6,000 years ago [2]. Before horses, hunters relied on geography and even elaborate wood corrals to trap and slaughter their prey [2]. The grass was eternal, home to many tribes including the Hunkpapa Sioux, Arapaho, Cheyenne, Crow, and others [4]. In the 18th century, the Powder River Basin was home to the Crow Indians, and towards the turn of the 19th century, Oglala and Brulé Lakota tribes arrived from Minnesota [2]. Cheyenne and Arapaho Indians, allies of the Lakota, hunted in southeast Wyoming [2]. The 1868 Fort Laramie treaty granted the whole northeast corner of what is now Wyoming to the Indians [2].

The Battle of Little Bighorn in 1876 was followed by the removal of Native Americans from the Powder River Basin [3]. Cantonment Reno, an army supply base at the Bozeman Trail crossing of the Powder River, was renamed Fort McKinney in 1878 and moved to a site on Clear Creek, officially opening the Powder River country to white settlers [2]. Cattle ranches emerged in the Powder River Basin in the late 1870s, and by 1883 sheep were taken into the basin as well [3]. The Homestead Act of 1862 brought almost six million settlers by 1890 who tried to replace grass with crops more beneficial to economic aspirations [4]. The 1909 Enlarged Homestead Act, also known as the Dry Farming Homestead Law, doubled the amount of free land available [3]. Settlers soon discovered, however, that while these vast grasslands were productive in wet years, they were also subject to serious drought and bitter winters [4]. Land that should never have been plowed yielded its topsoil to incessant dry winds; dust clouds rose to over 20,000 feet above parts of Oklahoma, Texas, Wyoming, Nebraska, Kansas, Colorado and the Dakotas [4]. Ten-foot drifts of fine soil particles piled up like snow in a blizzard, burying fences and closing roads [4].

The federal response reshaped the land. The National Industrial Recovery Act of 1933 and the Emergency Relief Appropriations Act of 1935 allowed the federal government to purchase and restore damaged lands and to resettle destitute families [4]. The Taylor Grazing Act became law in 1934, regulating grazing on public domain and ending almost all homesteading [3]. Thunder Basin National Grassland was initiated in 1934 as the Northeastern Wyoming Land Utilization Project under the Agricultural Adjustment Administration [1]. The program was also administered by the Farm Security Administration, Bureau of Agriculture and the Soil Conservation Service [1]. In 1954, the lands were transferred from the Soil Conservation Service to the Forest Service [1]. On June 23, 1960 — a hundred years after the Homestead Act — the National Grasslands were born, and the area was designated as the Thunder Basin National Grassland with permanent National Forest System status [1][4]. The Grassland was subdivided into three units for grazing administration, each with a grazing association [1]. In 1987, the TBNG was combined with the Laramie Peak area into the Douglas Ranger District [1]. Today, Cow Creek is protected under the 2001 Roadless Area Conservation Rule.

Vital Resources Protected

• Mixed-Grass Prairie Integrity. The roadless condition of Cow Creek's 17,917 acres protects an intact Northern Great Plains Mixed Grass Prairie within an ecosystem that has been reduced regionally by roughly half through direct conversion to crop fields and heavily grazed pastures. Unfragmented prairie of this scale preserves the soil structure, native bunchgrass cover, and prairie-scale processes — fire, drought response, ungulate movement — that disappear once a landscape is broken by roads, fences, and tillage corridors.

• Sagebrush and Saltbush Hydrologic Function. Great Basin Big Sagebrush Steppe, Intermountain Saltbush Flats, and Intermountain Greasewood Flat together govern how a small amount of annual precipitation is captured, slowed, and released across Archie Draw, Coal Draw, and the Lower Dry Creek headwaters. The roadless state keeps these shallow-cover plant communities intact, preserving the sparse but resilient ground cover that resists wind and water erosion on these particularly vulnerable fine-grained salt soils.

• Ponderosa Pine Woodland Islands. The Black Hills Ponderosa Pine Woodland and Savanna stands on rocky outcrops within the area function as habitat islands across an otherwise open prairie — providing nesting and roosting structure unavailable elsewhere on the landscape. Roadless conditions keep these stands' edges intact and their fire regimes accessible to natural ignition, both of which determine whether the islands persist as savanna or convert to denser, fuel-loaded woodland.

Potential Effects of Road Construction

• Fragmentation and Conversion of Mixed-Grass Prairie. Road construction across Northern Great Plains Mixed Grass Prairie introduces the linear disturbances and access corridors that historically have driven its 51% regional loss. Once a road grade is cut, the right-of-way and the access it provides invite invasion by non-native species, support edge effects that depress prairie obligate species, and create conditions under which adjacent acres become candidates for further conversion to crop fields or developed pasture — outcomes the unroaded prairie at Cow Creek currently forecloses.

• Wind and Water Erosion of Saltbush and Greasewood Flats. The naturally sparse plant cover and fine-grained salt soils of Intermountain Saltbush Flats and Intermountain Greasewood Flat make these shrublands particularly vulnerable to wind and water erosion wherever vegetation is depleted. Cut slopes and ditch lines from road construction would expose these soils directly, and disturbed ground in this ecosystem is slow to revegetate because declining water tables and salt accumulation patterns are themselves disrupted by hydrologic alteration along the road corridor.

• Cheatgrass Invasion of Sagebrush Steppe. Roads function as the primary vector by which invasive non-native annual grasses, particularly Bromus tectorum, enter Great Basin Big Sagebrush Steppe and Great Basin Big Sagebrush Shrubland. Once established along a disturbed road corridor, cheatgrass restructures the fire regime — shortening fire return intervals to the point where native sagebrush, which is not adapted to frequent fire, is eliminated from the system. The conversion from sagebrush steppe to annual grass monoculture, once initiated by a road corridor, is difficult to reverse on a management timescale.

Cow Creek spans 17,917 acres of arid prairie on the Douglas Ranger District of the Thunder Basin National Grassland. Recreation here is dispersed prairie recreation rather than developed front-country use: there are no campgrounds and no formal trailheads. Access is built around a small system of native-surface trails on the Cow Creek Buttes themselves, and around walk-in or horse-supported use of the surrounding draws and sagebrush flats.

The trail network is concentrated on and around the buttes. The Cow Creek Buttes Trail (1380) runs 4.5 miles and is the central route; the East Cow Creek Buttes 1 Trail (1384) adds 3.1 miles on the east flank, and the North Cow Creek Buttes Trail (1385) covers another 2.2 miles. Shorter spurs work the other faces — West Cow Creek Buttes 1 (1382) at 1.9 miles, South Cow Creek Buttes (1387) at 1.5 miles, Bobcat Creek (1381) at 1.3 miles, West Cow Creek Buttes 2 (1383) at 1.1 miles, and the short North Cow Creek Buttes Spur (1386) at 0.4 miles. All are native-material surfaces, and the routes around the buttes are designated for horse use. Combined, the system gives stock-supported and walk-in visitors roughly fifteen miles of trail across the area, with loop options around the major butte features.

Hunting is the primary use the area's roadless character supports. The mosaic of Northern Great Plains Mixed Grass Prairie, Great Basin Big Sagebrush Steppe, and Intermountain Mountain Sagebrush Steppe on the uplands, with Intermountain Saltbush Flats and Greasewood Flat in the bottoms and Black Hills Ponderosa Pine Woodland and Savanna on the rocky outcrops, supports a working prairie game complex. The lack of motorized incursion gives walk-in hunters undisturbed approaches across draws and into ponderosa stands that would otherwise be heavily edge-affected.

Birding and wildlife observation depend on the same conditions. The ponderosa pine islands on the buttes function as roosting and nesting structure for raptors and woodland songbirds across an otherwise open landscape, while the sagebrush flats and saltbush bottoms hold a different bird community keyed to sparse shrub cover. The Forest Service notes that across Thunder Basin generally many roads do not provide legal access to public land, and private landowner permission must be obtained before crossing private land. Within Cow Creek itself, the trail system gives lawful, on-foot or on-horseback access into ecological zones that would otherwise be unreachable.

Dispersed backcountry camping is permitted across the area, and the absence of designated campgrounds means visitors carry water and pack out everything they bring in. Photography of the buttes — particularly Archie Draw and Coal Draw at low sun — is a documented use, and the open horizons combined with the small isolated tree islands make for prairie compositions that motorized access would degrade. Every documented use of Cow Creek — the trail system, the prairie hunting, the birding from ponderosa stand to saltbush flat, the dispersed camping under open sky — exists in its current form because the area inside the trail network is unroaded.