Rock Springs Field Office

HMA Map

Great Divide Basin Herd Management Area

Horses in the Great Divide Basin herd management area.

The Great Divide Basin HMA encompasses 778,915 acres, of which 562,702 acres are BLM - administered public lands. The management area is located 40 miles east of Rock Springs, to the Rawlins/Rock Springs field office boundary, west to the Continental Divide, and north of I-80 to just south of South Pass City. The northern portion of the herd management area consists primarily of consolidated public lands with state school sections and small parcels of private land making up the remaining lands. The southern portion is in the checkerboard land ownership area created by the Union Pacific Railroad grant. Topography within the herd area is generally gently rolling hills and slopes with some tall buttes and streams. Elevations range roughly from 6,200 to 8,700 feet. Precipitation ranges 6-10 inches, predominately in the form of snow.

The AML for this HMA is 500 horses. Most horses are bay, sorrel, black, brown, paint, buckskin, or gray, but many colors and combinations are present. 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 weighs up to 1,100 pounds mature weight. The health of the horses is good with no apparent problems.

Domestic cattle and sheep utilize the area lightly in summer and moderately in winter. Vegetation in the HMA is dominated by sagebrush and grass intermixed with greasewood and saltbrush. The area also supports significant wildlife populations including elk, deer, and antelope.

How To Get There

We invite you to view wild horses; however, it is unlawful to chase and/or catch them. Please allow them to live a free and unmolested life.

The HMA is located north east of Rock Springs, Wyoming. The area can be accessed from Rock Springs by going approximately 35 miles east on I-80 and exiting on the Bitter Creek Interchange Exit #142. After exiting I-80 take County Road #19 north and you will be in the Great Divide Basin HMA. Another option is to take the Bar-X Exit # 152 off of I-80 and take County Road #21 north. County Roads are typically improved gravel roads maintained at scheduled intervals.

Therefore road conditions vary from very good to rough and rutted from wet weather and possibly impassable. It is easy to determine if you are in wild horse country by identifying the large piles of horse manure (stud piles) along road sides. Maps that cover this area are available at the Rock Springs Field Office located at 280 US 191 North. A quick stop at the field office would allow you to check local conditions and obtain maps.

The maps needed for this area are Red Desert Basin and South Pass. Before traveling to the area, make sure your vehicle is in good repair. If it has not stormed recently, you can make this trip in any full or mid-sized passenger vehicle, but a four wheel drive sport Utility Vehicle (SUV) is recommended. Make sure your spare tire is usable and have drinking water and emergency supplies with you. This area is fairly isolated, and it could be some time before help could arrive. Do not attempt to make this trip during inclement weather. Be especially cautious when there is snow on the ground. Travel in the area is restricted to existing roads and trails. Cross-country travel is not allowed. Don't forget to bring your camera and binoculars.

Help our wild horses by reporting illegal activity.
Contact your BLM office or call BLM Law Enforcement.

Rock Springs Field Office
280 HWY 191 North
Rock Springs, WY 82902
307-352-0256