The Warm Springs HMA covers 474,547 acres in southeast Oregon. Most of the wild horses were captured and removed in 2018 with the intent of supplying mares for sterilization research. BLM says it’s moving ahead with the study despite objections from most advocacy groups.
The plan was to return 200 horses to the HMA, including those that were ‘altered,’ to monitor herd behavior and growth. That has not happened and the operators who graze livestock in the area had unfettered access to forage this year, save for the thirty or so horses that escaped the helicopters.
The story at Warm Springs was the same one repeated by the government and major news outlets: The horses are out of balance with ‘other uses of public lands.’ But they rarely say what’s on the other side of the scales.
The HMA has an AML of 202. The horses graze twelve months per year, so their forage budget is 2,424 AUMs per year (202 × 12). The target population density is 0.4 horses per thousand acres (202 ÷ 474,574 × 1,000).
The pre-gather herd size was around 850 wild horses.
The HMA intersects two grazing allotments, used by seven operators. The acreage of the HMA differs slightly from the acreage of the allotments but for purposes of this post they are assumed to be coincident (subsequent calculations use 474,574 acres).
Table III-3 on page 87 of the Environmental Assessment for the Management Plan provides the allotment sizes, grazing seasons and permitted AUMs. Those figures are on the left side of this spreadsheet:
The forage allocated to livestock by plan amounts to 19,392 AUMs per year, compared to 2,424 AUMs for the horses. Keep in mind the land was set aside for the horses.
The permitted forage can be converted to cow/calf pairs by dividing the AUMs by the grazing seasons. The ranchers would have to place 2,030 cow/calf pairs on the West Warm Springs pastures to consume 11,167 AUMs in 5.5 months (11,167 ÷ 5.5 = 2,030).
The population density for livestock on that allotment would be 6.8 cow/calf pairs per thousand acres (2,030 ÷ 297,375 × 1,000).
The population density for livestock on the HMA is 8.1 cow/calf pairs per thousand acres, compared to 0.4 wild horses per thousand acres (3,858 ÷ 474,574 × 1,000).
The weighted average grazing season is five months (19,392 ÷ 3,858).
These figures are compared in the following charts.
Is this what they mean by ‘thriving ecological balance?’
The number of wild horses allowed on the HMA is not based on the carrying capacity of the land, but what’s left over after the lion’s share of the resources have been sold to the public-lands ranchers.
And how do roundups, contraceptives and sanctuaries fix this problem?
They don’t.
It’s time to end the ranching stranglehold on western rangelands and restore the WHB Act to its original form.
RELATED: Preview: Warm Springs Horses Get Short End of Stick.
Western Horse Watchers Association 
I agree 110%! I went to see this land just before the gather. The difference on the cow grazing side of the fence…eaten down to the roots of every plant, compared to a nibble here and there was eye opening. The cows also stood by their water area and really didn’t move….stomped the area into a muddy mess. Horses come drink and leave.
This HMA was very special. It contained a vast number of old blood line DNA and appaloosas. Some gaited as were the old stock raised my the Nez Perce. I was able to get 3 mustangs but the families were broken apart forever. Many shipped to Germany.
How dare they take this sacred HMA away from us, the public whom it belonged to. The exact horses BLM swore to protect!!! They got away with it with no consequences. This can not be undone.