National preserve, northwestern New Mexico, U.S. Established as a national monument in 1907, it was redesignated and renamed in 1980.
Occupying 53 sq mi (137 sq km), it contains 13 major pre-Columbian ruins and more than 300 smaller archaeological sites representing Pueblo cultures. Pueblo Bonito, built in the 10th century, is the largest Pueblo excavated site; it contained some 800 rooms.