From the record
“Navajo National Monument is a national monument located within the northwest portion of the Navajo Nation territory in northern Arizona, which was established to preserve three well-preserved cliff dwellings of the Ancestral Puebloan people: Keet Seel, Betatakin, and Inscription House. The monument is high on the Shonto plateau, overlooking the Tsegi Canyon system, west of Kayenta, Arizona.”
Wikipedia article Navajo National Monument, CC BY-SA 4.0.
One of 140 National Register listings published here for Coconino County · listed in 1966 · category: District · built in 1909.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service