In 1988, the Whitehorse Ranch joined the Bureau of Land Management, United States Fish and Wildlife Service, Oregon Department of Fish and Wildlife, Oregon Environmental Council, Oregon Cattlemen's Association, Oregon Trout, and the Izaak Walton League to found the Trout Creek Mountain Working Group. The group's goal was to review, discuss and resolve land use conflicts in the Trout Creek Mountains area of southeast Oregon. In 1989, the Whitehorse Ranch voluntarily removed its livestock from of its Whitehorse Butte grazing allotment and two other mountain pastures for a period of three years to prevent over grazing and allow watershed and riparian areas to recover from past grazing. The Trout Creek Mountain Working Group finally agreed on a long-term environmental sustainment plan in 1992. As part of that agreement, the Whitehorse Ranch agreed to reduce the number of its cattle that grazed on public lands from 3,500 to 800.