Nowhere else in Oregon can you hike through a 1,300-year-old lava flow inside an active volcano’s caldera—but such is the charm of the Big Obsidian Flow Trail, which offers a dramatic look at the region’s explosive past within the broader Newberry National Volcanic Monument.
The Big Obsidian Flow Trail, largely accessible between June and October, measures roughly one mile (round-trip) and challenges hikers with about 200 feet of elevation gain along the way. It takes visitors into the heart of Oregon’s youngest lava flow, offering up-close looks at glassy obsidian rocks and softer pumice rocks that cover one square mile.
Learn about the area’s natural history, geology, and other fascinating facts with seven interpretive panels that line the path—and take time to rest on benches along the trail and admire the disparate landscapes that sit within Newberry Volcano’s remarkable caldera (including old-growth forests and a pair of crystal-clear lakes). The trail is free of shade, so be sure to bring plenty of water if hiking in summer.
Rangers give talks at the on-site Big Obsidian Flow Amphitheater each summer, and a few picnic tables invite visitors to enjoy lunch or dinner in the shadow of the expansive lava flow.
Open Season
Late May-mid-Nov.
Dog Friendly and/or Leash Rules
Due to the rocky, jagged nature of this trail, dogs are not advised.
Best time to visit
June-Oct.
Don’t Miss
Get started early to enjoy cooler temperatures and enjoy solitude at the eerie landscape.
Fees or Pass Needed
A Forest Pass ($5 per day pass or $30 per annual pass) or America the Beautiful pass ($80 per annual pass) is accepted.
Restrictions
Motorized vehicles (including e-bikes) are not permitted on the trail.
Activities
Hiking
Viewpoint
Parking
Parking is available at the Big Obsidian Flow Trailhead.
Directions
From La Pine, the 21-mile drive to the Big Obsidian Flow Trailhead takes about 35 minutes via northbound Highway 97 and Paulina-East Lake Road.