Pitchstone Plateau Trail

Pitchstone Plateau Trail is a remote backcountry point-to-point route from Phantom / Pitchstone Trailhead (8K4) on South Entrance Road to the Mountain Ash Creek Trail junction. Yellowstone lists it at 16.3 miles one way; the mapped tread measures about 17.1, and another route guide gives 17.7, so plan for roughly 17 miles. The payoff is the plateau’s open lava country, meadows and a high-point view south to the Tetons. Allow roughly nine hiking hours and arrange a pickup before you start: this is not a loop, and the far end is another trail junction, not your car.

The trail starts with a short flat stretch, then climbs about 320 feet in the first half-mile up the plateau’s eastern edge. It keeps gaining more gradually through lodgepole forest burned in 1988. Phantom Fumarole appears around mile 4.8: a small, mostly dry thermal area with a few steam vents and mud pots. The ground here can be dangerous; stay on the established trail. If the fumarole is your main goal, a separate out-and-back from the same trailhead is about 9 to 9.5 miles.

Past the campsites near mile six, trees thin and the meadows open up. The tread gets faint, so watch for the chain of rock cairns instead of assuming the path will stay obvious. The low ribs breaking up the meadow are folds in the solidified lava, with glassy obsidian and pitchstone fragments nearby. Snow can linger on this wet corner of the park well into July. In late summer, springs near those campsites are the only reliable water reported along the plateau; carry enough and treat what you collect.

Around mile nine, the route reaches its high point. The Tetons are to the south; open plateau meadows spread to the north. It then bends back into trees and drops roughly 1,700 feet over the final eight miles to the Mountain Ash Creek junction. Bison and elk sometimes use the open meadows, though sightings are never a sure thing. For a photo, include one of the low lava ribs in the foreground with the Tetons beyond; the ribs make the plateau’s unusual surface easier to read.

Treat this as a serious backcountry crossing: carry a map and know how to navigate, especially where the tread fades. The park recommends hiking in groups of three or more, prohibits pets on trails and in the backcountry, and requires a permit for overnight camping. The west end is a trail junction, so arrange your exit before setting out.