Explore 8 Midwest National Monuments
Agate Fossil Beds National Monument
On the grassy plains of western Nebraska, Agate Fossil Beds National Monument is best known for its fossils dating from the early Miocene age about 20 million years ago. A visitor center showcases ancient mammals (including dwarf rhinos and beardogs) as well as a collection of Native American artifacts. Trails leading out from the center take visitors to the sites where fossils have been found (308/668-2211; nps.gov/agfo).