Vandals in New Mexico sprayed graffiti and caused other damage at one of North America's largest petroglyph sites that protects ancient American Indian rock art.

Dennis Vasquez, superintendent of Petroglyph National Monument near Albuquerque, recently found graffiti, debris, evidence of campfires and motorcycle tracks while exploring a section of the park.

It was unclear if any of the artwork was damaged.

The monument has thousands of centuries-old Pueblo Indian markings of symbols and animals and is managed jointly by the National Park Service and the city.

Albuquerque crews are removing litter and debris and restoring sections of downed fence. Vasquez says the Park Service and the city will work to remove the graffiti as quickly as possible and try to prevent permanent damage.