The Selway-Bitterroot Wilderness covers almost 2,000 mi2 in east-central Idaho and western Montana (fig. 1). The wilderness lies across the Bitterroot Range, which forms the boundary between Idaho and Montana, and includes large portions of the drainages of the Selway, Lochsa, and Bitterroot Rivers. Elevations range from 1,800 ft on the Selway River near the wilderness boundary to 10,157 ft at Trapper Peak in the Bitterroot Mountains. Specific areas within the wilderness mentioned in this report are shown in figure 1.