About the North Hills Herd Management Area
The North Hills HMA comprises about 49,900 acres of BLM-administered, state and private lands. The HMA is managed in cooperation with the United States Forest Service (USFS) – Dixie National Forest, Pine Valley Ranger District’s North Hills Wild Horse Territory, which consists of approximately 24,029 acres. Together, the combined area is referred to as the North Hills Wild Horse Management Plan Area (WHMPA). The WHMPA is located in Iron and Washington Counties, about 2 miles northwest from Enterprise, Utah.
The North Hills WHMPA is approximately 74,000 acres and is located within an east west trending mountain range approximately 2 miles northwest of Enterprise, Utah. The wild horses primarily use the lower elevation toe-slopes and canyons. The area is jointly managed with the adjacent USFS Wild Horse Territory. The BLM has management lead for the two areas. The soils within the area are sandy with considerable amounts of surface rock and scattered rocky outcrops within the canyons resulting in wild horses having difficulty traveling long distances and having to take circuitous routes between water and forage.
The WHMPA averages 5,500-6,000+ feet in elevation, and supports vegetation types of big sagebrush and pinyon and juniper trees. The pinyon and juniper trees dominate the WHMPA and is very dense with minimal under story forage. Open areas outside of the pinyon and juniper canopy are dominated by big sagebrush with Indian Ricegrass and needle-and-thread grass as the primary forage species. There are warm season grasses which supplement these cool season species.
The WHMPA has one reliable summer water source (Nephi Spring), which is located on the south boundary of the USFS Wild Horse Territory (on FS property). The water is a spring source with abundant water flow. The water is located in a canyon with rocky outcrops along the north side and a vegetation jumble of pinyon/juniper, big sagebrush, and riparian vegetation such as cottonwood and willow. The riparian area is heavily trampled and over grazed with non-riparian vegetation encroaching. Animal distribution to other portions of the WHMPA is hampered by topography and vegetative cover types. Scattered ponds exist throughout the WHMPA occasionally providing water to the horses. These ponds rely on large thunder storms or heavy winter run-off in order to provide water and are not reliable from month to month.
There are approximately 250 wild horses within the HMA and Wild Horse Territory. Traditionally, the lack of forage within close proximity of the Nephi Spring is causing wild horses to begin using more areas outside of the HMA and Wild Horse Territory. The lack of water and forage during the summer months, combined with the distance the must travel over rocky ground, results in rapid physical deterioration of the animals. In addition, overlapping wildlife dependence for the same habitat as the wild horses necessitates actions to preserve their physical condition.
The last removal of excess wild horses from the North Hills WHMPA was completed in July of 2007 when 88 horses were gathered and 86 were removed. Following the 2007 gather, two stallions were released back into the WHMPA. The un-gathered population was estimated at approximately 50 animals.
The current estimated population of wild horses within the WHMPA is estimated at 250 head. This number is based on an aerial survey direct count of 90% of the total population based on coverage, weather, terrain, tree cover, snow cover, and knowledge of the WHMPA/horses, which estimated the population at that time to be at 208 head of wild horses. The population inventory was conducted in January of 2010. It is estimated that in the spring of 2010 the foal crop and survival of those foals increased the estimated wild horse population within the WHMPA by 20%. When the 20% increase of the 2010 spring foal crop is added to the population inventory the current population in the WHMPA is estimated at 250 head or 500% above AML.