Hesselbarth W, Vachowski B, Davies MA (2007). "Signs". Trail construction and maintenance notebook. Missoula, MT: USDA Forest Service Technology and Development Program. p. 125. OCLC959245369.
Fuller, Margaret (2002). Trails of the Frank Church-River of No Return Wilderness (2nd ed.). Weiser, Idaho: Trail Guide Books. p. 208. ISBN9780966423327. OCLC50596610.
Hesselbarth W, Vachowski B, Davies MA (2007). "Signs". Trail construction and maintenance notebook. Missoula, MT: USDA Forest Service Technology and Development Program. p. 125. OCLC959245369.