You'll see a lot of wildlife on the Petrified Tree Trail, a moderately trafficked, 0.1 miles out-and-back trail that features lovely wildflowers and is suitable for all skill levels for walking, nature trips, and bird watching from March until October. The trail is kid-friendly, but no dogs are allowed. This region isn't the most exciting in the park, but you'll discover much of the park's geological history. The trailhead is behind Roosevelt Lodge (if you take a left first, you can see the Lost Falls), then continue to Lost Lake before hitting The Petrified Tree. Continue up the hill to the right past the parking lot for the Petrified Tree to finish the loop. There were three petrified trees in Yellowstone until some souvenir hunters ravaged two of them. The remaining tree had been fenced off since then. The petrified tree is a clue to the warmer, damper, violent Yellowstone landscape. When volcanoes erupted 50 million years ago, they triggered massive landslides into valleys and streams. The rolling mix of ash, water, and sand buried entire forests. Before the trees could rot, the silica in the volcanic flow plugged the living cells and created stone forests.