The Owyhee Complex includes five Herd Management Areas (HMAs), Little Humboldt, Little Owyhee, Owyhee, Rock Creek and Snowstorm. The gather area is located within Elko and Humboldt Counties. The Owyhee, Rock Creek and Little Humboldt HMAs are administered by the Elko District (Tuscarora Field Office). The Little Owyhee and the Snowstorm HMAs are administered by the Winnemucca District, (Humboldt River Field Office).
Little Humboldt HMA: The Little Humboldt HMA is located in northwestern Elko County, approximately 90 miles northwest of Elko, Nevada, and is the smallest HMA with 17, 151 acres (15,734 public/1,417 private). The AML is 48-80 wild horses.
Owyhee HMA: The Owyhee HMA comprises the northeast portion of the Complex and is 17 miles wide, 37 miles long and encompasses 336,262 public-land acres and 2,025 acres of private land for a total of 338,287 acres. The AML is 139-231 wild horses.
Rock Creek HMA: The Rock Creek HMA is located in the southeastern portion of the Owyhee Complex and is located just south of the Owyhee Desert. The Rock Creek HMA contains 98,169 acres of public land and 23,264 acres of private land with an AML of 150-250 wild horses.
Little Owyhee HMA: The Little Owyhee HMA is the largest of the five HMAs and is located in the northwestern portion of the Owyhee Complex. The Little Owyhee HMA encompasses 454,416 acres of public land and 5,811 acres of private land with an AML of 194-298 wild horses.
Snowstorm HMA: The Snowstorm HMA is located in the southwestern portion of the Owyhee Complex. The Snowstorm HMA contains 103,644 acres of public land and 13,465 acres of private land with an AML of 90-140 wild horses.
Topography/Vegetation: The Owyhee Complex is located in the Owyhee Desert area within the Columbia Plateau and Great Basin physiographic regions. These regions are located in the Great Basin which is one of the largest deserts in the world. It is characterized by a high rolling plateau underlain by basal flows covered with thin loess and alluvial mantel. On many of the low hills and ridges that are scattered throughout the area, the soils are underlain by bedrock. The Owyhee Complex is occasionally cut by deep, vertically walled canyons and steep rugged mountains. Elevations range from about 4,570 feet to 7,737 feet.
The primary vegetation in the Owyhee Complex is big sagebrush-bunchgrasses and low sagebrush-bunchgrasses. The major plant associations are dominated by big sagebrush, low sagebrush, shadscale, spiny hopsage, budge sage, rabbit brush and winterfat. Major bunchgrass species include bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, indian ricegrass, Thurber's needlegrass and bottlebrush squirreltail. Forbs include arrowleaf balsamroot, lupine, phlox and aster.
Climate: Climate within the Owyhee Complex is characterized by warm dry days, cool nights and low yearly precipitation that ranges from four inches at lower elevations to approximately 16 inches at higher elevations. Most precipitation occurs as winter snow and spring rains.
In the Great Basin high desert of Nevada, the average annual precipitation is often less than 11 inches (which defines the term desert). Drought conditions occur as frequently as six out of every 10 years.