A little info below.

“The Kasha-Katuwe Tent Rocks National Monument is a remarkable outdoor laboratory, offering an opportunity to observe, study, and experience the geologic processes that shape natural landscapes. The National Monument, on the Pajarito Plateau in north-central New Mexico, includes a national recreation trail and ranges from 5,570 feet to 6,760 feet above sea level. It is for foot travel only, and contains two segments that provide opportunities for hiking, birdwatching, geologic observation, and plant identification.

The cone-shaped tent rock formations are the products of volcanic eruptions that occurred 6 to 7 million years ago and left pumice, ash, and tuff deposits over 1,000 feet thick. Tremendous explosions from the Jemez volcanic field spewed pyroclasts (rock fragments), while searing hot gases blasted down slopes in an incandescent avalanche called a “pyroclastic flow.”

Precariously perched on many of the tapering hoodoos are boulder caps that protect the softer pumice and tuff below. Some tents have lost their hard, resistant caprocks, and are disintegrating. While fairly uniform in shape, the tent rock formations vary in height from a few feet up to 90 feet.”