Crack-in-the-Ground is an ancient volcanic fissure over 2 miles long and up to 70 feet deep. Normally, fissures like this one are filled with soil and rock by the processes of erosion and sedimentation. However, because it is in such an arid region, very little filling has occurred, and Crack-in-the-Ground exists today nearly as it did shortly after its formation thousands of years ago.
For more information, visit https://www.blm.gov/visit/crack-ground