Sheep Rock

Image of Sheep Rock.
The John Day River flows north past Sheep Rock on its way towards the Columbia.

NPS / Anderson

The Sheep Rock Unit is located on Highway 19, near the towns of Kimberly Oregon and Dayville Oregon. Geological formations found in the Sheep Rock Unit, including the green claystone layers of the Turtle Cove Member, date back 32-7 million years. New vertebrate fossils are continually being exposed through natural erosion.

Unit Features:

Foree trails
Green claystones at the Foree trailhead

NPS photo

Colorful Strata...

The Sheep Rock unit contains an amalgam of colorful strata and complex geology. From Cretaceous conglomerates to the flood basalts, the geologic features in this portion of the monument are a spectacle to behold.

The predominant exposures of green rock seen on Sheep Rock are a multitude of reworked layers of volcanic ash. The rich green color of the claystone was caused by chemical weathering of a mineral called celadonite. This happened millions of years ago as water moved through the alkaline ash beds under high pressure.

Last updated: December 8, 2017

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Mailing Address:

32651 Highway 19
Kimberly, OR 97848


(541) 987-2333

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