Gypsum Sinkhole

Gypsum Sinkhole is a geologic stop in the Cathedral District: a nearly 50-foot-wide collapse pit that drops about 200 feet into layered rock. I'd stop if I'm already making the remote valley drive; I wouldn't make this the only reason for going. It's a striking, short visit after a long stretch of rough road.

From the Highway 24 junction, the sinkhole is 25.6 miles along Cathedral Road on the counterclockwise route. The full loop is 57.6 miles and usually takes six to eight hours. High clearance is required, and 4WD may be needed depending on conditions. Rain, snow and washouts can make the dirt roads impassable. The return leg on Hartnet Road crosses the Fremont River at an unbridged ford; check its condition and don't cross during high water. There is no potable water in Cathedral Valley.

Groundwater dissolved a buried plug of gypsum and left a cavity. The overlying rock collapsed into it, exposing the curved layers around the opening. It is a reminder that the red-rock landscape has softer, easily dissolved material hidden inside it.

The layered bowl is the view, and the park identifies this as a scenic photo stop. Frame the curved rim as well as the dark center to show the sinkhole's scale. Keep well back: the rock around the edge is soft and unstable and can collapse without warning.