Clarno Unit

Two people read a sign along a trail. A large cliff dominates the skyline behind them.
The Clarno Palisades are the eroded remnants of ancient volcanic mudslides.

NPS photo / Tim Gohrke, 2018 Artist in Residence

The Clarno Unit is located 18 miles west of the town of Fossil, Oregon. The Palisades are the most prominent landform and are volcanic lahars, or mudflows, that formed 54-40 million years ago in a lush semi-tropical rainforest environment. Tiny four-toed horses, huge rhino-like brontotheres, crocodilians, and meat-eating creodonts that once roamed ancient jungles are now found in the rocks of the Clarno Unit, as well as an incredibly diverse range of plant life. Leaves, fruits, nuts, seeds, and petrified wood from 173 species of trees, vines, shrubs, and other plants have been found here thus far.

Glimpses of fossilized plants can be seen along the cliff walls.

Unit Features:

  • Trails

  • Picnic Area

  • Restroom Facilities

  • Water is not available


Trails at the Clarno Unit

This map zooms in to the area along Highway 218 to show where the Geologic Time Trail, the Trail of Fossil, and the Arch Trail are in relationship to each other and the picnic and parking areas.
The trails at the Clarno Unit are all located at or near the picnic area along Highway 218.

NPS map

The Palisades Trailhead is located ¼ mile west of the picnic area along Highway 218. The Trail of Fossils and the Clarno Arch Trail start at the trailhead. There is limited parking at this area. The Geologic Time Trail connects the trailhead with the picnic area, where additional parking is available.

Trail of Fossils (¼ mile loop) This is the only trail in the park where visitors can readily see fossils in the rocks. Large boulders strewn below the Palisades contain dozens of visible plant fossils from the near-tropical forest that blanketed the region 44 million years ago.

Clarno Arch Trail (¼ mile round trip) A 200 foot elevation climb brings visitors directly under a natural arch cut into the cliff by erosion. Petrified logs are visible in the cliff face.

Geologic Time Trail (¼ mile each way) This trail connects the picnic area and trailhead. Signs along the way note events of the last 50 million years. Each foot of trail represents 37,000 years.


Clarno Fossil Layers

44 Million Years Ago, Oregon was Semitropical

Clarno Nut Beds (44 Million Years ago)

Over 170 identified plant fossil species have been identified and includes leaves, seeds, nuts, and wood.

Hancock Mammal Quarry has a large concentration of fossils.

Hancock Mammal Quarry- 40 Millions Years

Temperatures and rain decrease compared to the Clarno Nut Beds but remained mostly above freezing.


Other Places to Visit in the Monument

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.

Eroded claystone reveals the past with blue, tan, pink, and brown rock layers.

Sheep Rock Unit

Home to the Thomas Condon Paleontology Center and the Cant Ranch Museum, the Sheep Rock Unit also has many trails and scenic views.

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: September 26, 2021

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32651 Highway 19
Kimberly , OR 97848


541 987-2333

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