The geologic formations within the 20-square-mile area of the John Day Fossil Beds contain a remarkable, diverse fossil record covering roughly 40-million years of earth's history. This record provides a view of a large portion of the Tertiary Period, a time when mammals and flowering plants were undergoing dramatic changes. ![]() Painted Hills Unit
Reknowned for the varied hues found in the exposed volcanic layers. This area also is home to a diverse assemblage of leaf fossils. ![]() Clarno Unit
See the Palisades, a cliff formed by a series of ancient volcanic mudflows (lahars) that now is high above the surrounding landscape. ![]() Sheep Rock Unit
The green claystone layers seen here date back 30 million years. New vertebrate fossils continue to be exposed through natural erosion. ![]() Geologic Formations
Learn more about the geologic formations that exist in the park. ![]() Rivers and Streams
Learn about the John Day River and other rivers in the park. ![]() Soils
Soils are a product of the geology of the area. Read about soil in the park. |
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Last updated: August 29, 2024