Sheep Rock Unit

Sheep Rock is an outcropping - not quite a hill but not quite a mountain. It is vaguely pyramid shaped, with a basalt capstone and blue-green and pink sedimentary layers below.
Sheep Rock is named after the bighorn sheep that once populated its slopes.

NPS Photo by Tim Gohrke, 2018 Artist-in-Residence

The Sheep Rock Unit is located on Highway 19, between the towns of Kimberly and Dayville, Oregon. Prominent, non-fossil bearing rocks date back as far as 95 million years old. Fossils of plants and animals are found in a number of geological layers dating from 33-7 million years ago.

The Sheep Rock Unit is the hub of monument operations, with the Thomas Condon Paleontology Center located near the namesake peak, and the headquarters of the monument at the Historic Cant Ranch.

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.

A map depicting major destinations in the Sheep Rock Unit, including the Foree Trailhead, the Blue Basin Trailhead, the Cant Ranch Historic District, the Thomas Condon Paleontology Center, and the Mascall Overlook.
Map of the Sheep Rock Unit

NPS Photo

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!

Foree Trailhead

  • Flood of Fire (0.4 miles round trip)
  • Story in Stone (0.3 miles round trip)

Blue Basin Trailhead

  • Island in Time (1.3 miles round trip)
  • Blue Basin Overlook (3.25 mile loop)

James Cant Ranch Historic District

  • River Trail (0.6 miles round trip)
  • Sheep Rock Overlook Trail (0.5 miles round trip)

Thomas Condon Paleontology Center

  • Thomas Condon Overlook Trail (¼ mile round trip)

Mascall Overlook

  • Mascall Formation Overlook (430 feet round trip)
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    Fossil Layers of the Sheep Rock Unit

    30-25 million years ago, the forest canopy gradually opened allowing more open spaces.

    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.

    Grasses make their mark on the landscape and its fauna.

    Upper John Day (24-20 Ma)

    The ecosystem became an open habitat with the appearance of burrowing and running animals.

    As grasslands expanded some species thrived while others slowly died out.

    Mascall (15 Ma)

    Long-legged hoofed animals including horses, camels, and giraffe-deer swiftly crossed open meadows to escape beardogs and cats.

    Welcome to the semiarid wooded shrubland with giant sloths and saber toothed felines.

    Rattlesnake (7 Ma)

    The ecosystem preserved here is more familiar to modern eyes- except for the occasional elephant and giant sloth.


    Other Places to Visit in the Monument

    Clarno is the best place to see fossils in situ.

    Clarno Unit

    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 consists of fossilized soils from wet forests no longer found in eastern Oregon.

    Painted Hills Unit

    The colorful stripes and gentle ripples of the Painted Hills makes it one of the most popular destinations in the park.

    The monument's visitor center and research facility.

    Thomas Condon Paleontology Center

    The Thomas Condon Paleontology and Visitor Center displays fossils from the entirety of the John Day Fossil Beds.

    Last updated: June 17, 2022

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    32651 Highway 19
    Kimberly , OR 97848


    541 987-2333

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