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 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 Challis HMA is located at the East Fork of the Salmon River. The herd area is bordered on the north by the Salmon River, on the west by the East Fork of the Salmon River, on the south by the ridgeline between Herd Creek and Road Creek and on the east by U.S. Highway. It encompasses 154,150 acres of public land.
Elevations range from 4,600 feet to nearly 8,000 and reach slopes up to 80 percent. High ridges with patches of Douglas fir and wide sagebrush basins, dissected by drainages with active riparian areas containing willows, birch and aspen.
Wildlife living in the area include elk, pronghorn, mule deer, sage grouse as well as many rodents, birds of prey and songbirds. The HMA also provides critical winter range habitat for big game species, as well as a full complement of large predators with mountain lions, bears, and wolves.
The Challis HMA has an Appropriate Management Level of 185 horses.
The dominant colors for the present day HMA are gray, black, and bay. About 21% of the horses in the 1973 inventory were grey or progeny of grays. Other colors noted were sorrel, red roan, and pintos.
Mature horses average approximately 1000 pounds and are 14-16 hh. Confirmation is considered good with the large stature being the greatest trait of the herd.
Idaho's wild horses are descendants of domestic horses that escaped to or were turned out on the public lands prior to passage of the Wild Free-Roaming Horses and Burros Act of 1971. During the Great Depression in the 1930's, many farmers and ranchers released their animals onto public lands because they couldn't afford to feed them.
It is believed that the wild horses near Challis originally started from the livestock miners and ranchers brought to the area around 1870. John Bradbury is the first person known to have introduced horses into what is now the Challis wild horse area. Other early day ranchers frequently released stallions into the herd to improve or upgrade the quality. Additionally, several breeds of work horses were released into the area. Ranchers depended on work horses for their livelihood and therefore bred work stock among the wild horses.
The Challis Herd is comprised of hardy stock. They are generally larger than most wild horses that live in rugged, steep mountainous regions. Herd genetics are very diverse, with little possibility of becoming inbred.
A total of 46 blood samples were taken during the 2002 gather in order to create baseline data for establishing the current level of genetic diversity for the HMA. Dr. Gus Cothran, a geneticist, conducted the tests at University of Kentucky. A summary of these results indicates the following:
· Genetic variation is well above average for both wild and domestic breeds.
· Genetic similarity. The highest mean was with the New World Spanish breeds, followed closely by North American Gaited breeds. However, a dendrogram of genetic similarity of the Challis herd to domestic breeds placed the Challis herd within the cluster of the Heavy Draft and True Pony breeds. This likely indicates a mixed breed origin for the herd which also accounts for the high variability and high proportion of rare genes.
· Variation in the Challis herd is fairly high, most likely due to a mixed breed origin of the herd and a relatively high recent population size.
· The Challis herd is a single interbreeding group.