Big Hole is a large volcanic maar, or explosion crater, in central Oregon’s Fort Rock basin, northeast of Crater Lake near Oregon Route 31. About 6,000 feet across and 300 feet deep, it is one of the basin’s notable volcanic landforms. It lies near Hole-in-the-Ground, a smaller and less eroded maar in the same area. Together, these craters help define the Fort Rock basin’s distinctive high-desert landscape, where broad open terrain is broken by abrupt circular depressions created by explosive volcanic activity.