Yellowstone National Park in Wyoming, USA hosts a Fossil Forest.
Yellowstone National Park contains the largest known Petrified Fossil Forests in the world.
The hike into Yellowstone National Park's Fossil Forest begins at an unmarked trail-head in Lamar Valley. One-way access is 1.5 miles (2⅜ KM) with vertical elevation of 1,200 ft (395 M). The trail begins on the faded remnants of an old service road.
Along this short, straight stretch there is a herd of about 30 buffalo grazing 100 yards (30 M) away. There are young in the herd so it is important to maintain safe distance.
Soon the old road veers right and morphs into a rustic trail which gradually climbs through grassland punctuated with sagebrush and colorful shrubbery to a stand of trees where trail incline increases substantially. Occasionally there are distinct specimens of petrified forest along the route.
The steep, sandy, loose, volcanic gravel makes footsteps challenging and unstable so tree branches and brush frequently assist stability. Intertwining trails make route finding more challenging and occasionally intuitive.
After a few exploratory missions the hike proceeds by trial and error to reach the destination on the side of a ridge overlooking incredible vistas across the surreal Lamar Valley and Slough Creek bracketed by surrounding meadows and mountains.
Along the trail there is copious evidence of the massive Petrified Forest. When the ascent trail emerges from forest there are huge petrified trees and amazing vistas from the ridge. The massive redwood stump in front of us is 26 ft (8½ M) in circumference with two smaller petrified trees standing below it. The roots are atypically still intact.
By scrambling carefully down the steep, loose rock below the trees it can be determined the tree's root systems and branches are incredibly intact. Tree rings are clearly visible.
This fossil forest is world-renowned and was created 50 million years ago when large forests were buried in mud flows caused by volcanic eruptions. Once the trees were buried, the air spaces within them were plugged by silica from the volcanic ash. As the wood gradually decayed the trees turned to stone.
Most of the trees in this 40-square-mile fossil forest are redwoods but there is also evidence of magnolia, avocado and dogwood, indicating a much warmer ancient climate.
When the lay of the land becomes more familiar and route-finding is less an issue, many more petrified tree specimens are discovered on the return hike by an alternate route across the top of Specimen Ridge where outstanding views of Mount Washburn and the north end of the Grand Canyon of the Yellowstone are accented by many patches of spectacular open meadow which more than justify the effort.
On the return approach to the trail-head, the herd of buffalo has moved onto the trail so there is a sensible obligation to head head off-trail and stepping carefully through the meadow they previously occupied to give the herd a wide berth on the return to the car parked at the trail-head.
Wandering through the Yellowstone National Park Fossil Forest has been a humbling experience where 50 million year old fossils occupy the same ground where eyes widen and imagination soars. The texture of the fossilized trees is remarkably beautiful.