APA (7th ed.) Citation

United States. National Park Service. (1999). National park system map and guide: [United States] ([1999 rev. ed.].). The Service.

Chicago Style (17th ed.) Citation

United States. National Park Service. National Park System Map and Guide: [United States]. [1999 rev. ed.]. Washington, DC: The Service, 1999.

MLA (9th ed.) Citation

United States. National Park Service. National Park System Map and Guide: [United States]. [1999 rev. ed.]. The Service, 1999.