Mummy Cave in northwestern Wyoming is a broad rock shelter whose dry, stable volcanic setting preserved rare organic remains and a deeply layered record of human use. Occupied from about 7280 BC to AD 1580, it yielded more than 28 feet of deposits divided into 38 occupation levels, creating one of the Rocky Mountains' most important long-term archaeological sequences. Excavations in the 1960s helped establish dating and comparison standards across the region, including a typology for stone projectile points in the American West. Finds also documented long-term changes in climate, population, hunting practices, and cultural traditions, including the remains of Mummy Joe.