By Conor Watkins Grand Gulf State Park, near Koshkonong, MO, is home to what has been called Missouri s Little Grand Canyon and The Little Grand Canyon of the Ozarks. As with many natural features in Missouri, Grand Gulf was formed by karst processes.
Grand Gulf is the remains of a massive collapsed cave system.
Its natural bridge and caves are remnants of the original cavern. The cave serves as the drain for the water in Grand Gulf and the some of the surrounding area. Water from Grand Gulf resurfaces at Mammoth Spring in Arkansas, which is nine miles away. The tracing of this water was done by adding special dyes to the water at Grand Gulf and watching them re-appear at Mammoth Spring around a day later. Two streams draining a combined 26 square miles of land are captured, or pirated by Grand Gulf.