Specimen Ridge Day Hike Trailhead is a trailhead on Lamar River in Yellowstone National Park, WY.
Beginning from this unmarked trailhead in the western part of Lamar Valley, a strenuous 1.5 mile long trail (one-way) leads up to a petrified forest with many upright and fallen petrified trees. This trail is not connected to the longer trail that traverses the entire ridge. See Specimen Ridge Trailhead.
Hundreds of petrified trees, some 8 feet in diameter and 20 feet tall, are located near the cliffs on the ridge above the trailhead. The trees are remains of 50 million-year-old fir and sequoia trees which fossilized in silica-rich soil. Petrified trees can also be found standing alongside pine trees in the forest right below the cliffs.