Salmon Mountain Lookout stands on Salmon Mountain in the Idaho portion of the West Fork of Bitterroot National Forest near Darby, at 8,943 feet in the Frank Church River of No Return Wilderness. Salmon Mountain has the oldest documented use as a lookout site on the Bitterroot Forest, with a 1915 journal recording fire observation there using a phone line, tent camp, and a rock wall around a portable alidade. A log cabin lookout with an observation cupola was built in 1928, and the present 1936-pattern L-4 building replaced it in 1949. Still staffed by volunteers, it was listed on the National Register of Historic Places in 2018.