United States. Forest Service. (1985). Changing canyon trail. The Service.
Chicago Style (17th ed.) CitationUnited States. Forest Service. Changing Canyon Trail. [Washington, D.C.?]: The Service, 1985.
MLA (8th ed.) CitationUnited States. Forest Service. Changing Canyon Trail. The Service, 1985.
Warning: These citations may not always be 100% accurate.