Skeleton Cave, a lava tube on Newberry Volcano’s northern flank in central Oregon, was formed by ancient volcanic activity and is estimated to be 75,000 to 400,000 years old. Its name reflects the many bones found inside, which sparked early scientific interest after documentation in the early 20th century and evidence of an 1894 visit. Researchers concluded that animals likely fell in through the skylight entrance and became trapped, leaving remains that included a Pleistocene horse, a very large bear, and species such as deer, elk, dire wolf, lynx, foxes, and short-faced bear. Later surveys mapped the cave more fully, and recent management has aimed to protect its fragile resources and hibernating bats.