Crack in the Ground is a volcanic fissure that formed at the western boundary of a small graben underlying the Four Craters Lava Field. The Crack and lava field were recently dated at about 14,000 years old. The fissure is about 2 miles long and 70 feet deep, and disappears into lake sediments at its southern end. Therefore, this supports an interpretation that Lake Fort Rock rose no higher than this level in the last 14,000 years.

The length of the fissure can be hiked as there is an established trail along the fissure's bottom. Normally, fissures like this one are filled in with soil and rock by the processes of erosion and sedimentation, but because Crack in the Ground is located in such an arid region, barely any filling has occurred. As a result, Crack in the Ground exists today nearly as it did shortly after its formation.

To get to Crack In The Ground there is a turn off about two miles East of Christmas Valley, then about 6 or 7 miles of cinder road to the parking area at the site. When you get there it is easy to cool off as the bottom of the crack can be as much as twenty degrees below the surface temperature.