• Two

    John Day Fossil Beds

    National Monument Oregon

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Geologic Formations

The rock layers of the John Day Fossil Beds spread far beyond the boundaries of the National Monument.
 
Image of a map of Oregon with the geological formations shown in different colors.
The fossil bearing rocks of the John Day basin are wide spread.
 
Image of the John Day Fossil Beds timeline.

Rocks at the fossil beds are stacked up like layers of a cake.Click on the timeline for a larger version.

The oldest layers are on the bottom, the youngest layers are on the top.

To learn more about each of these different Formations click on the links in the index on the left side of this page. They are (from youngest to oldest) the Rattlesnake, Mascall, John Day strata, and Clarno formations.

Did You Know?

Image of the painted hills

The Painted Hills at the John Day Fossil Beds National Monument are made of heavily eroded volcanic ash layers.