The pinkish colored rocks on the slopes and in the cliffs above you are volcanic tuff. About 1.6 and again 1.2 million years ago, there was a tremendous series of volcanic eruptions (600 times larger than the blast from Mount St. Helens in 1980) from the Jemez (HAY-mez) Mountains just northwest of here. Ash from the explosions was deposited across the nearby landscape in thick layers creating the Pajarito (Pah-ha-REE-toe) Plateau. Some ash was carried on the prevailing winds forming thin deposits as far away as Iowa. Looking closely at the tuff, a sandy texture is apparent. Volcanic tuff here is porous and relatively soft. Running water erodes it quickly, cutting deep, steep-walled canyons like this one.
Last updated: February 24, 2015