The Public Lands Council issued a news release today condemning a decision by the BLM to change the livestock type and grazing seasons on seven allotments near the Charles M. Russell National Wildlife Refuge in the northern half of the state.
The project began with the acquisition of base properties by American Prairie that secured grazing preference on the allotments.
American Prairie then submitted a plan to the BLM to graze bison on those allotments.
Refer to Map 1-1 in Appendix A of the Final EA for the arrangement and Section 1.1 for an overview (pages 93 and 7 in the pdf).
The Allotment Master Report puts five of the allotments in the Improve category, one in Maintain and one in Custodial.
The Authorization Use Report shows five of the allotments permitted for cattle and two for indigenous animals.
The long-term effect of bison on rangeland health is not known.
The BLM news release said the allotments currently provide 7,969 AUMs across 63,500 public acres, or 125 AUMs per year per thousand acres.
That resource would support ten wild horses per thousand acres (125 ÷ 12).
The government has stated repeatedly that public lands in the western U.S. can only support one wild horse per thousand acres (27,000 animals on 27 million acres).
The Virginia Range was carrying ten wild horses per thousand acres before the advocates got involved. Now they’re forcing the herd into the government box.
Western Horse Watchers Association 
These numbers and studies have to be figured out by children! No long term studies on how BISON will affect the rangeland! Read your history books! The bison numbered in the millions before the white men started their killing spree! And there was plenty of grazing for them and the mustangs. The Native Americans had huge herds of horses. The whites killed their livelihood, for the bison provided so much of what they needed to live and the horses that provided transportation and wealth.