National Park Service

U.S. Department of the Interior Specimen Ridge Day Hike Yellowstone National Park

Cautions

All Wildlife: You must stay at least 

100 yards (91 m) away from bears and 

wolves; and at least 25 yards (23 m) away 

from all other animals—including birds.

Bears: Although your chance of 

an encounter is low, your safety 

is not guaranteed. Minimize your 

risks by making loud noises, 

shouting, or singing. Hike in 

groups and use caution where vision is 

obstructed. Carry bear spray and know 

how to use it. Do not hike after dark. 

Avoid carcasses; bears often defend this 

food source. 

Fishing: Anglers must have a 

Yellowstone National Park fishing permit in their possession. Consult the park 

newspaper for purchase locations.

Backcountry Camping: Permits are 

required for backcountry camping.

Loose Rock: Watch your footing; be 

careful not to kick loose rocks onto hikers below you, and watch for rocks from 

above.

Collecting natural or cultural 

objects—like rocks, feathers, 

flowers, antlers, arrowheads, and 

other artifacts—is illegal. Please 

leave everything where you find it. Approx. 1 mi/1.6 km

Open

Sage

Open

Sage

Open

Ridge

Cliff Outcrop

Petrified Tree Trunks

Lamar River

Bridge

Abandoned

Service Road

Crystal Creek

To Tower Junction 4.5 miles/7.2 miles

To Northeast Entrance

^

North

Hiking route described

Roads

^ Parking

Welcome to the Petrified Trees of Specimen Ridge

Overlooking a valley of the Lamar River, Specimen Ridge offers outstanding views and an unparalleled opportunity 

to observe Yellowstone’s geology up close. The route shown on this map takes you directly to this fascinating site. 

The other side of this sheet explains the geology of Specimen Ridge. Always carry rain gear, extra food and water, and 

other emergency equipment when venturing into the backcountry. Be sure to obtain current trail conditions and bear 

activity information at the Tower Backcountry Office.
For more information

www.nps.gov/yell

Visitor centers have a free day hike handout for each major area of the park. A “Day 

Hike Sampler,” with a hike or two per area, is also available along with several guides 

for trails throughout the park. 

Yell 232 • 02/15

Trail Description

Don’t confuse this route with the 

Specimen Ridge Trail. 

Distance, round trip: 3.0 miles (4.8 km)

Estimated time: 2–4 hours 

Difficulty: extremely strenuous

Trailhead: striped pullout 

4.5 miles (7.2 km) east of Tower Junction 

on the Northeast Entrance Road. 

Marked by a sign reading “trailhead.”

This strenuous, high elevation trail is not 

recommended for persons with heart 

and/or respiratory problems.

This trail is not a part of the longer Specimen Ridge Trail. The Petrified Trees of 

Specimen Ridge is a separate, unmaintained and unmarked route. 

From the pullout, look southwest, away from the road. Toward the top of the ridge, at 

approximately the two o’clock position, you will see a cliff outcrop that contains the 

petrified trees. Keep this in mind as your ultimate destination.

To begin your hike, follow the abandoned service road from the pullout for about 100 

yards (91 m). Veer right onto the intersecting path and start climbing toward the ridge. 

Stay on the most obvious trail to the top of the open ridge. Follow the ridge line to the 

southwest in the direction of the cliff outcrop you saw from below. There are several 

wildlife trails that cut across below the top of the ridge, and traverse a forested area 

before ending at the trees. Be careful not to get off track on the wildlife trails.

Take in the magnificent view across the valley. To the north, you can see the Slough 

Creek Valley and Absaroka Range. Descend the way you came up.

Additional references

www.yellowstoneassociation.org

www.greateryellowstonescience.org

Yellowstone Resources & Issues (annual), Yellowstone National Park & Yellowstone Association

Windows Into the Earth: The Geologic Story of Yellowstone and Grand Teton National Parks, Robert B. Smith and Lee J. Siegel

Interpreting the Landscape: Recent and Ongoing Geology of Grand Teton and Yellowstone National Parks, John M. Good and 

Kenneth L. Pierce

Roadside Geology of Yellowstone Country, William J. Fritz

Geology Underfoot in Yellowstone Country, Marc S. Hendrix

What is petrified wood?

Petrified wood is a fossil of woody vegetation. 

Most fossils are imprints of plants or animals. Petrified wood is a threedimensional fossil that is created when trees, or tree parts, are covered 

by silica-rich sediment. Water seeping through the sediment dissolves 

the minerals in the soil and penetrates the cells of the tree. As it flows 

through the plant tissue, it leaves the minerals behind to replace the 

vegetable matter with stone. 

About Specimen Ridge

Nearly 150 species of fossil plants from Yellowstone have been found, 

spanning 500 million years, from the Cambrian to the Holocene. 

Most petrified wood and other plant fossils come from Eocene 

deposits about 50 million years old, which occur in many northern 

parts of the park. 

Best known are the fossil forests of Specimen Ridge, where the remains 

of hundreds of these 50-million-year old trees stand exposed on a steep 

hillside, with trunks up to eight feet in diameter and some more than 20 

feet tall. The specimens include sequoia, fir, and numerous deciduous 

species. 

The first fossil plants from Yellowstone were collected by the early 

Hayden Survey parties. An 1878 report referred to fossil “forests” on Amethyst Mountain opposite the mouth of Soda Butte 

Creek.

Around 1900, F. H. Knowlton proposed the theory that the petrified trees on Specimen Ridge were forests petrified in place. His 

theory remained dominant through most of the 20th century. 

A more recent theory proposes the trees were uprooted by volcanic debris flows and transported to lower elevations. The 1980 

eruption of Mount St. Helens supported this idea. Its mud flows transported trees to lower elevations and deposited some trees 

upright—similar to what you see on Specimen Ridge.

Take only photos—Collecting natural or cultural 

objects is illegal.