Indian Ruins, Walnut Canyon National Monument, Arizona
Walnut Canyon National Monument
In densely-wooded plateau country southeast of Flagstaff, the small seasonal stream Walnut Creek has carved a 600 foot deep canyon as it flows east, eventually joining the Little Colorado River en route to the Grand Canyon. The exposed Kaibab limestone that forms the upper third of the canyon walls occurs in various layers of slightly differing hardness, some of which have eroded more rapidly forming shallow alcoves; during the 12th to 13th centuries many were used by the local Sinagua Indians who constructed cave-dwellings along the steep well-protected ledges, high above the canyon floor.