Agate Fossil Beds National Monument is in northwestern Nebraska. It has the fossil bones of extinct animals that lived about 20 million years ago. The fossils include those of two-horned rhinoceroses and of animals that had horselike heads, rhinoceroslike forelegs, bearlike hindlegs, and clawed feet. The monument was authorized in 1965. For its area, see National Park System (table: National monuments).
