Petty John's Cave popular destinations of the cave. Formations in Petty John's Cave include: Stalagmites that are a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. Stalactites are also found in the cave. These formations hang from the ceiling or wall of the cave. There are also pillars, soda straws, cave pearls, flowstones, and cave popcorn are other formations in the cave. In addition, waterfalls can be found in the stream passage section. This cave hosts tri-colored bats during their winter hibernation because temperatures are low
Black Canyon of the Colorado the Nevada side of the canyon is the Sauna Cave. This cave was drilled by miners working on Hoover Dam while it was being constructed. It is a deep cave with calcium carbonate crystals on the walls. At the end of the cave is a hot spring, which causes temperatures in the cave to reach . One prominent canyon that splits from this canyon south of the Hoover Dam is Boy Scout Canyon. Boy Scout Canyon has water running through it that is warmed from a geothermal source. On the Arizona side of the river, there are several large hot