Definition of john day fossil beds national monument in English English dictionary
National monument, north-central Oregon, U.S. With an area of 14,014 acres (5,676 hectares), it is located along the John Day River (named after a Virginian scout of the 1811 Astor overland expedition). Fossils more than 30 million years old provide a paleontological record of five epochs of the Cenozoic Era