Indigenous people inhabited what became Arizona more than 12,000 years ago. Today, 22 American Indian communities preserve their cultures and traditions on land that accounts for one-quarter of Arizona. From the Navajo Nation in the high country—the largest reservation in the United States—to picturesque areas along the fertile flood plains of the Colorado River, the forests of central Arizona and the vibrant Sonoran Desert of Southern Arizona, American Indian communities share unique cultural experiences with visitors.