Fossil Butte definitely paints a vastly different picture of this area than what you see today. Today you see a flat open desert with just a bit of squat bushes dotting the landscape. Some 50 million years ago, however, this was a sub-tropical lake supporting hundreds of thousands of fish and other animals of many different species. These animals provide the fossils that give the park its name and that provide clues to the climate, plants and animals in the area's past. Start your visit at the visitors center where you can get prochures and maps of the park, learn more about the fossils and the history of the area, and get recommendations on how to best enjoy your visit. Hours are 8 AM to 4:30 PM October through April and 9 AM to 5:30 PM May through September. Weather may affect the opening of the park. Entrance is free!