National Park Service. (1990). Petroglyph National Monument: Boca Negra Canyon; trail guide. National Park Service.
Chicago Style (17th ed.) CitationNational Park Service. Petroglyph National Monument: Boca Negra Canyon; Trail Guide. Albuquerque: National Park Service, 1990.
MLA (9th ed.) CitationNational Park Service. Petroglyph National Monument: Boca Negra Canyon; Trail Guide. National Park Service, 1990.
Warning: These citations may not always be 100% accurate.