The historic town, established in the 1880s, was named when a fossilized mammoth bone was found in the vicinity. True to its name, Fossil offers visitors a chance to do some free prospecting at the public fossil-collecting site in town. This ancient lakebed deposit contains numerous leaf imprints of ancient deciduous trees as well as a few vertebrate fossils.

John Day Fossil Beds National Monument.

The area is comprised of three widely separated units: the Sheep Rock Unit, the Painted Hills Unit and the Clarno Unit. Each offers picnic areas, restrooms, information kiosks, hiking trails with exhibits and brochures and outstanding scenery. The main visitor center, located at the Sheep Rock Unit, features displays of fossils found throughout the John Day Basin. Hours vary throughout the year. Few places so accessible to the public present a better selection of fossilized bones, shells, leaves wood, teeth, tracks, nuts and seeds. These artifacts provide an informative overview of the Age of Mammals—the 40 million years that elapsed between the extinction of the dinosaurs and the beginning of the Ice Age. The Clarno formation in the Clarno Unit, just 18 miles from the town of Fossil, consists primarily of huge mudflows or lahars, which roared down the slopes of ancient volcanoes, engulfing everything in their paths. Although the Clarno volcanoes have long since eroded, the hardened lahars remain—along with fossilized plants and animals trapped in the flows.