Petroglyph National Monument stretches 17 miles (27 km) along Albuquerque, New Mexico's West Mesa, a volcanic basalt escarpment that dominates the city’s western horizon. Authorized June 27, 1990, the 7,236 acre (29.28 km²) monument is cooperatively managed by the National Park Service and the City of Albuquerque. The western boundary of the monument features a chain of dormant fissure volcanoes.