Walnut Canyon National Monument protects about 3,600 acres of canyon landscape and archaeological remains southeast of Flagstaff, Arizona. On the Colorado Plateau, Walnut Creek carved limestone alcoves that allowed the Sinagua to build more than 80 cliff dwellings between about 1125 and 1250. Living here from about 1100 to 1250 AD, they adapted to a dry, demanding environment by conserving water, raising maize, beans, and squash, and likely trading over long distances. The canyon’s geology also supports unusual plant diversity. Created as a national monument in 1915 to preserve the ancient dwellings, the site later gained further recognition for its historic importance and dark skies.