Fun on four western rivers :
Middle Fork of the Salmon, Selway, Main Salmon, Snake-Hells Canyon.

APA Citation

United States. Forest Service. Pacific Northwest Region., United States. Forest Service. Intermountain Region., United States. Forest Service. Northern Region. (1987). Fun on four western rivers: Middle Fork of the Salmon, Selway, Main Salmon, Snake-Hells Canyon. [Washington, D.C.?]: USDA Forest Service, Northern, Intermountain, and Pacific Northwest Regions.

MLA Citation

United States. Forest Service. Pacific Northwest Region, United States. Forest Service. Intermountain Region, and United States. Forest Service. Northern Region. Fun On Four Western Rivers: Middle Fork of the Salmon, Selway, Main Salmon, Snake-Hells Canyon. [Washington, D.C.?]: USDA Forest Service, Northern, Intermountain, and Pacific Northwest Regions, 1987.