WHITE MOUNTAIN HERD MANAGEMENT AREA
The White Mountain HMA encompasses 392,649 acres, of which 240,416 acres are BLM- administered public lands. The majority of the HMA consists primarily of checkerboard land ownership area created by the Union Pacific Railroad grant. Consolidated public lands with state school sections and small parcels of private land make up the remaining lands in the northeast section of the HMA. The HMA is a high plateau that overlooks Rock Springs. Elevations range roughly from 6,300 to 7,900 feet. Precipitation ranges 6-10 inches, predominately in the form of snow. The area is unfenced except for portions of boundary fence and right-of-way boundaries along I-80, and 191 north.
The Appropriate Management Level for this HMA is 250 horses. A full range of colors is present. This herd has a lot of color in it, many of which are paints. Other colors are bay, sorrel, red roan, black, or gray. The Wyoming horses have a diverse background of many domestic horse breeds. They are most closely related to North American gaited breeds such as Rocky Mountain Horse, American Saddlebred, Standardbred, and Morgan. The horses range from 14 to 15.5 hands and weigh between 750 and 1,100 pounds mature weight. The health of the horses is good.
Domestic cattle and sheep utilize the area lightly in the summer and moderately in the winter. Vegetation in the HMA is dominated by sagebrush and grass, with saltbrush, winterfat, and greasewood intermixed. Horses typically use a high amount of grass species, the most favorable being needlegrass, Indian ricegrass, wheatgrass, and Sedges. The area supports significant wildlife populations including elk, deer, and antelope.