capital of the extensive Navajo Nation Reservation, Apache county, northeastern Arizona, U.S. It lies 23 miles (37 km) northwest of Gallup, New Mexico. Established in 1936 as the Central Agency Headquarters to consolidate the many Indian agencies scattered throughout the reservation (which overlaps New Mexico and Utah), the town was named for the huge wind-eroded opening in the sandstone cliffs that overlook the administrative buildings from the north. The focal point is the octagonal Navajo Council House where the tribal council meets. The Navajo Nation Zoo and Botanical Garden, containing plant and animal species that are of cultural importance to the Navajo, and the Navajo Nation Fairgrounds, where the annual Navajo Tribal Fair is held, are located at Window Rock. So, too, is the Navajo Tribal Museum. Pop. (1990) 3,306; (2000) 3,059.