A tornado came through the area in the 1920 s, which ripped up trees and blew them into Grand Gulf. These trees washed into the cave and have acted as a gigantic clog to its natural drain. The cave is now inaccessible past the clog and water no longer quickly drains from Grand Gulf. After heavy rains, the water can become 50-75 feet deep and take weeks to drain from the basin. Although many have tried to clear the debris from the cave, no one has been successful.
Grand Gulf consists of a larger main canyon and a smaller side canyon.
Both of these branches were once part of a cave system. A fault runs through the area and is thought to be associated with the formation of the gulf. Within the past 10,000 years, the rock composing roof of the cavern became too weak due to fracturing and dissolution rock and collapsed. Most of the cave collapsed, but a small part is left as a large natural bridge. It is thought that the gulf was not formed all at once.