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Winnemucca District/Elko District

BLM Wild Horse & Burro Program LogoOwyhee Complex Wild Horse Gather

About the Owyhee Complex HMAs

Owyhee Complex Gather Q&As

Owyhee Complex Wild Horse Gather Area:
The Owyhee Complex Wild Horse Gather 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.

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 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. Currently, most of Nevada is experiencing widespread severe and extreme drought which has resulted in substantially reduced production of forage grasses and water sources needed for wild horses and wildlife on the range.

Common wildlife species within the Complex include coyote, black-tail jackrabbit, desert cottontail, bobcat and numerous raptors, reptiles and other small mammal species. Mule deer and pronghorn antelope are common big game species in the area. Elk are common in the Rock Creek HMA and a small number of elk inhabit the Owyhee HMA primarily during the winter period near Desert Ranch Reservoir. Currently, the overabundant population of wild horses is adversely affecting valuable habitat needed to support both wildlife and wild horses.

Population Size and Appropriate Management Level (AML):
The following table displays the current estimated population within these HMAs. 


2012 Estimate 1

Current Population2






Rock Creek 




Little Humboldt




Little Owyhee












  • 1Population estimate originally included in the Preliminary EA based on May 2011 surveys
  • 2Population based on September 2012 surveys

Owyhee Complex Wild Horse Characteristics:   

Wild horses are primarily descendants of ranch horses and cavalry remounts. The dominant colors in the Owyhee Complex are gray, bay, black, brown and roan. Most wild horse herds sampled have high genetic hetrogygosity, genetic resources are lost slowly over periods of many generations, and whild horses are long-lived with long generation intervals (Singer and Zeigenfuss, 2000). Based on past gather and field observations, there are no signs of inbreeding which suggests that the Owyhee Complex wild horses are genetically diverse. The AML within the Owyhee Complex (621-999) is at a level that supports genetic diversity. The wild horse population size at AML should promote adequate conditions for genetic health even after excess wild horses are removed.

The Owyhee, Rock Creek, and Little Humboldt HMAs in the Elko District as well as the Little Owyhee, and Snowstorm HMAs within the Winnemucca District are all contiguous and generally separated only by fencing. Movement does occur (and has been observed) between these HMAs through open gates and crossings, but no formal research has been completed to determine the extent of this movement. Management of the wild horses in these HMAs at the established AML ranges and as an interacting population regardless of boundaries (i.e., as an HMA Complex) would ensure continued genetic diversity and health. Even slight movement helps to diversify the herds.

Livestock Grazing Management: 
Based on escalating drought conditions, all permittee’s in the Elko and Winnemucca Districts have been notified this is a drought year and they should prepare for temporary changes to their grazing use. Permittee's have been asked to continue to observe conditions and speak with their Rangeland Management Specialist on a regular basis to help mitigate the effects of drought. Many of the permittee's that have allotments within the Owyhee Complex are aware of the current situation and have been voluntarily making livestock adjustment throughout the 2012 grazing year.

The Bullhead, Little Humboldt, Little Owyhee, Owyhee, Spanish Ranch, and Squaw Valley Allotments are managed for livestock grazing but portions of these allotments also overlap with HMA boundaries and those overlapping areas are consequently managed concurrently for wild horses. There are a total of seven livestock operators (permittees) currently authorized to graze livestock in these allotments annually. The total permitted use for these permittees is a combined total of 127,029 Animal Unit Months (AUMs) yearly in the 6 allotments (including on non-HMA lands). An AUM is the amount of forage needed to sustain one cow or its equivalent for one month (43 CFR 4100). All of these allotments consist of various pastures that are grazed seasonally following established grazing systems; however, the season of use may vary (by one to two weeks) annually based upon forage availability, drought conditions and other management criteria.

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