[8] They exhibit a wide range of solid colors, including bay, black, chestnut, dun, grullo, and blue or red roan.

[8] The head is convex (sometimes called a "Roman nose) or straight, with wide-set eyes, hooked ears, and a broad forehead that tapers well to the muzzle.

[6][8] The front teeth meet evenly, the upper lip is usually longer than the lower, and the nostrils are small and crescent shaped.

[11] Thousands of feral horses lived in the area by the time American pioneers began settling near the Pryor Mountains in the late 1800s.

[14] By 1968, the wild herd were concentrated mostly on BLM lands owing to previous roundups and construction of boundary fences.

[12] That year, the BLM again stated its intention to remove the herds, this time with the possibility of returning a small number (either 15 or 35) to the range.

In response to the new announcement, the Pryor Mountain Wild Horse Association (PMWHA) was formed with the goal of preventing the roundup, and began working in concert with larger organizations such as the International Society for the Protection of Animals.

[17] The battle over the Pryor Mountain herd moved to the national level on July 11, 1968, when ABC broadcast a special on the horses on the evening news.

At the same time, the BLM was unresponsive to efforts by members of the public, senators and officials from the Humane Society of the United States to ascertain final plans regarding the horses.

[21] After the creation of the refuge the BLM appointed a committee to study the area and make recommendations regarding appropriate herd numbers.

The committee, which met in late 1968 and early 1969, was made up of range and wildlife experts, local citizens interested in the herds and representatives from several federal, state and private organizations.

[23] On December 18, 1971, the Wild and Free-Roaming Horses and Burros Act of 1971 (WFRHBA) was signed into law by President Richard M. Nixon.

The Act made it a crime for anyone to harass or kill feral horses or burros on federal land, required the departments of the Interior and Agriculture to protect the animals, required studies of the animals' habits and habitats, and permitted public land to be set aside for their use.

In 1992, equine geneticist Dr. E. Gus Cothran conducted genetic studies on the herd, and concluded that their primary bloodlines did descend from Spanish Barbs.

[30] Rather, they were linear descendants of the Spanish Barb, with some evidence of genetic similarity to light racing and riding breeds.

In general, BLM initially focused on how many horses the range could support and in maintaining conformity to the Pryor Mountains standard.

However, with the development of DNA testing in the mid 1980s, the focus changed to include maintaining the herd's genetic viability.

[6][37] BLM counts the herd visually about every four years by flying over the range, reporting on each animal found, and using statistical methods to correct for historic undercounting and other problems.

Since adopters favored "pretty" horses, the color genetics of the herd altered so that mostly bays and blacks were left on the range.

[6] In May 2009, after several long-term studies of the rangeland, the BLM determined that the range's maximum carrying capacity was 179 feral horses.

[37] The Cloud Foundation and Front Range Equine Rescue, both feral horse advocacy groups, challenged the roundup in federal court.

[47][48] BLM began its roundup of feral horses on the Pryor Mountains range in early September 2009.

A guzzler is a precipitation (usually rainwater) collection device which traps water in a storage tank ranging in size from a few to several thousand gallons.

[53] In the fall of 2010, BLM issued a set of draft strategy documents for operating its wild horse programs, and solicited public comment on the plans.

[54] After receiving numerous comments, BLM said in February 2011 it would quicken the pace at which it made revisions to its roundup procedures, use of fertility control drugs, and wild horse and burro range land management.

[54] The results of the study by the NAS were released in June 2013, and covered a wide variety of issues, including the carrying capacity of wild horse and burro ranges, wild horse and burro population growth, and best practices in fertility control.

Overall, the NAS was critical of the BLM, saying that herd populations were increasing at an "unsustainable rate" and that the "BLM fails to effectively use contraception tools", criticizing the methods used for estimating populations and available forage, and stating that the agency has failed to communicate appropriately with the public.

[56] The range can be easily accessed via a paved road which parallels Bighorn Canyon, and which provides excellent viewing of the horses.

[57] The range can also be accessed from Laurel, Montana, by traveling south on U.S. Route 310 and then taking the Forest Service gravel road to Dryhead Overlook.

[59] Hiking on the Pryor Mountains Wild Horse range is good, but there are no maintained or marked trails and (as of 2000) no guidebooks to the area.