Ashfall Fossil Beds State Historical Park

The Ashfall Fossil Beds of Antelope County in northeastern Nebraska are rare fossil site types called lagerstätten that, due to extraordinary local conditions, capture a moment in time ecological "snapshot" in a range of well-preserved fossilized organisms. Ash from a Yellowstone hotspot eruption 10-12 million years ago created these fossilized bone beds. The Ashfall Fossil Beds are especially famous for fossils of mammals from the middle Miocene geologic epoch. The Ashfall Fossil Beds are stratigraphically part of the Serravallian-age Ogallala Group. The site is now protected as Ashfall Fossil Beds State Historical Park, which includes a visitor center with interpretive displays and working fossil preparation laboratory, and a building over an ongoing excavation site featuring fossil Teleoceras (native hippo-like ancestral rhinoceros) and ancestral horses.