Grand Gulf State Park with it's natural features, is a spectacular collapsed chasm that is three-quarters of a mile long. 50 to 200 feet wide and up to 120 feet deep. A portion of the collapsed cavern's roof remains and forms one of the largest natural bridges in Missouri. Other geologic features include an underground stream, cave, and one of the outstanding Ozark examples of subterranean stream piracy. Interesting terrestrial communities include moist and dry limestone/dolomite cliffs. Water flowing into the remaining portion of the cave has been traced to Mammoth Spring, AR by Toney Aid of West Plains, MO. Take Hwy 19 S about 25 miles from Alton.

Grand Gulf State Park