Map 2 in Appendix A of the 2015 EA for resource enforcement actions indicates that the HA overlaps most of the Twin Buttes Allotment and a small part of the East Douglas Creek Allotment.
The HA covers covers 128,141 total acres, including 123,387 public acres, according to Section 1.2 of the EA.
The AML is zero. No resources have been assigned to the horses, although the area was identified for them in 1971.
The Western Watersheds map does not show herd areas but Western Horse Watchers added its boundary based on the map in the EA. Click on image to open in new tab.
West Douglas includes 113,790 acres from Twin Buttes and 9,530 acres from East Douglas Creek per Section 5.6.1 of the EA. These values determine the percentage of the allotments inside the HA.
The Allotment Master Report from RAS provides acreage, management status and active AUMs. All of the land is in the Improve category.
The average forage density in the two allotments is 79 AUMs per year per thousand acres, enough to support at least six wild horses per thousand acres.
Resources in the allotments must be considered when estimating the carrying capacity of areas designated for wild horses. They are routinely ignored by the advocates in their efforts to spread the Montana Solution across the American west.
The forage assigned to livestock inside the HA would support 9,991 ÷ 12 = 832 wild horses, for a True AML of 0 + 832 = 832.
The stocking rate at the new AML would be 6.7 horses per thousand acres.
The 832 horses displaced from the HA by permitted grazing represent about 1.5% of the animals in off-range holding. Every horse in short-term and long-term holding can be explained by this principle.
Most of the horses were removed from the area last August in an emergency roundup prompted by wildfire and drought but the allotment data suggest otherwise.
The incident was not necessary from a resource viewpoint and was likely carried out to protect the public-lands ranchers.
RELATED: West Douglas Horses Hit Hardest at Cañon City Corrals.
Western Horse Watchers Association 
Excellent analysis. The BLM in cahoots with the ranchers are acting shamelessly to deprive the wild horses of their rightful land/habitat and natural life style/freedom. This is based on sheer narrow-minded, tunnel vision selfishness and greed — that is destroying precious Life.