Canyon de Chelly National Monument (icon ) was established on April 1, 1931 as a unit of the National Park Service

National Park Service

The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations...

. It is located in northeastern Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 within the boundaries of the Navajo Nation

Navajo Nation

The Navajo Nation is a semi-autonomous Native American-governed territory covering , occupying all of northeastern Arizona, the southeastern portion of Utah, and northwestern New Mexico...

. Reflecting one of the longest continuously inhabited landscapes of North America, it preserves ruins of the early indigenous tribes that lived in the area, including the Ancient Pueblo Peoples

Ancient Pueblo Peoples

Ancient Pueblo People or Ancestral Pueblo peoples were an ancient Native American culture centered on the present-day Four Corners area of the United States, comprising southern Utah, northern Arizona, northwest New Mexico, and southern Colorado...

 (also called Anasazi) and Navajo

Navajo Nation

The Navajo Nation is a semi-autonomous Native American-governed territory covering , occupying all of northeastern Arizona, the southeastern portion of Utah, and northwestern New Mexico...

. The monument covers 83840 acre and encompasses the floors and rims of the three major canyons: de Chelly, del Muerto, and Monument.