Great Expectations Cave Nature Preserve

Great Expectations Cave contains almost eight miles of surveyed passage with a vertical extent of more than 1,400 feet. It is the fifth deepest limestone cave in the United States, the second deepest cave in Wyoming, and the second-longest cave in Wyoming. Great Expectations Cave contains Wyoming’s largest room, The Great Hall, more than 2,000 feet long and up to 100 feet high and wide. The cave is located at an elevation of 8,500 feet on a pristine creek in the Bighorn Mountains, Wyoming.

The creek sinks into the cave at the entrance and reappears approximately six miles down the canyon, near the lower entrance to the cave, the Great Exit. The Great Exit, near the “Grim Crawl of Death,” is on Federal land managed by the U.S. Bureau of Land Management. This high-altitude karst area contains several other significant caves including Tres Charros Cave, Bad Medicine Cave, and P-Bar Cave.

The NSS acquired the main (upper) entrance to Great Expectations Cave and Johnny Creek Cave in January 2003 to ensure that NSS members have access to the cave and the surface property for recreation, exploration, science, and surveying. The 40-acre property has an eastern boundary with the Bighorn National Forest and a northern boundary with lands managed by the U.S. Bureau of Land Management. The western and southern boundaries border private land. The preserve is accessible for about six months a year due to snow.