This vibrant scene is gone now because of profound climate changes and the disappearance of the lakes. But the site of ancient Fossil Lake and many of the fossils that tell its story will be protected in perpetuity at Fossil Butte National Monument. Here, paleontologists and park visitors alike can discover the past. Fossils of Ancient Fossil Lake For number, variety , and detail of fossil fish, few places can equal ancient Fossil Lake. Its fossils enable us to take a close look at what life was like at Fossil Lake 50 million years ago.
Fish are the most common fossils by far.
Besides the fossil fish, there are hundreds of other forms of life captured in stone. The delicate bones of a fossil bat, the oldest known in North America, and a remarkably complete fossil snake were preserved here. No one knows for sure, but after careful study scientists have developed theories to explain the process. One essential ingredient for preservation, they believe, was rapid burial in calcium carbonate, which precipitated out of the water and fell like a constant gentle rain to the bottom of Fossil Lake. Year after year for hundreds of thousands of years, this reoccurred.