The plan sanctions the killing of 36 mountain lions by hounds, snares and firearms to reduce predation on bighorn sheep in the Tonto National Forest and Four Peaks Wilderness area, southwest of Roosevelt Lake. Bighorns once roamed the area in larger numbers but were nearly extirpated by hunting, habitat destruction, drought, and disease from livestock. Despite these factors, it is legal to hunt the bighorns, and the study area serves as a federally authorized domestic sheep driveway, through which thousands are herded to reach grazing allotments. Another factor not considered in the study is that livestock grazing in the Four Peaks Wilderness has contributed to a decline in the mule deer population, and resulted in higher predation levels on bighorns than other areas.