APA (7th ed.) Citation

United States. National Park Service. (2013). Yellowstone National Park, Idaho/Montana/Wyoming ([2012 revised edition].). National Park Service, U.S. Department of the Interior.

Chicago Style (17th ed.) Citation

United States. National Park Service. Yellowstone National Park, Idaho/Montana/Wyoming. [2012 revised edition]. [Washington, D.C.]: National Park Service, U.S. Department of the Interior, 2013.

MLA (9th ed.) Citation

United States. National Park Service. Yellowstone National Park, Idaho/Montana/Wyoming. [2012 revised edition]. National Park Service, U.S. Department of the Interior, 2013.