In 1971, wild horses and burros were found roaming across 53.8 million acres of Herd Areas (HAs), of which 42.4 million acres were under the Bureau of Land Management’s (BLM’s) jurisdiction. Today the BLM manages wild horses and burros in subsets of these HAs, known as Herd Management Areas (HMAs) that comprise 31.6 million acres, of which 26.9 million acres are under BLM management.
The 670,000-acre Eagle HMA is located in Lincoln County, Nevada. The 38,995-acre Chokecherry and 34,047-acre Mt. Elinor HMAs are located in western Beaver and Iron counties, Utah, adjacent to the Eagle HMA. All three HMAs consist of large mountain ranges bounded by valleys. Elevations range from about 5,673 feet in the valleys to as high as 9,296 feet on Mt. Wilson.
The HMAs afford a classic Great Basin environment marked by extremes of almost every kind. Summertime temperatures can exceed 100 degrees Fahrenheit, and winter lows can fall well below zero or lower. Precipitation in eastern Nevada and western Utah occurs mostly in the winter in the form of snow with sparse summer moisture. Summer rains are localized, short and very intense while winter/spring rains are gentler and over a wider area. Annual average precipitation varies from approximately 14 inches at the higher elevations to 8 inches or less at the lower elevations. Water sources are limited to a very few natural springs and man-made wells. There are also a few small perennial streams within the HMAs. As a result of limited water, the HMAs are prone to drought every few years.
Vegetation in the HMAs is characteristic of the Great Basin with dominant plants having evolved to survive the extremes. Typical vegetation varies according to elevation with the upper mountain slopes generally covered with stands Aspen, fir and open meadows. Through the mid elevations, pinion and juniper trees are dominant and often form closed stands which prevent other vegetation from growing. As the elevation and moisture supply falls, the vegetation shifts towards shrub dominated community. Sagebrush is the most common shrub along the pinion juniper perimeter. Sagebrush gives way to white sage, black sage, saltbrush, and other “salt Desert shrub” type communities.
Wildlife in the area includes mule deer, elk, mountain lions, coyotes, and bobcats. There are also prairie falcon, ravens, quail, starlings, and horned larks. Reptiles include many species of lizards, poisonous (rattlesnakes) and non-poisonous snakes