McWethy, David B., author.
Fort Collins, Colorado : U.S. Department of the Interior, National Park Service, Natural Resource Program Center, 2010.
2010
United States. Congress. House. Committee on Natural Resources. Subcommittee on National Parks, Forests, and Public Lands.
Washington : U.S. G.P.O. : For sale by the Supt. of Docs., U.S. G.P.O., 2008.
2008