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.
Hiking Trails in the Sheep Rock Unit
There are seven hiking trails in the Sheep Rock Unit, ranging from 0.25 miles to 3.25 miles in length. The trails are listed from north to south, arranged by trailhead. Please remember to recreate responsibly and Don't Hurt the Dirt!
Blue Basin Trailhead
James Cant Ranch Historic District
Thomas Condon Paleontology Center
Fossil Layers of the Sheep Rock Unit
Turtle Cove (30-25 Ma)
Turtle Cove is the thickest and most productive fossil-bearing layer within the John Day Fossil Beds, yet few leaf fossils were preserved.
Other Places to Visit in the Monument
The Clarno Unit is home to the oldest exposed layers of the John Day Fossil Beds, and the only place in the monument to see "wild" fossils.
Painted Hills Unit
The colorful stripes and gentle ripples of the Painted Hills makes it one of the most popular destinations in the park.
Last updated: June 17, 2022