Big Obsidian Flow Trail Hiking Guide
The Big Obsidian Flow Trail climbs onto a field of black volcanic glass and pumice in the Newberry Caldera, south of Bend. The Forest Service dates the flow to about 1,300 years ago, making it the youngest lava flow in Oregon, and the short interpretive loop lets you walk right across it. Here is what to expect and when the season ends.
Permit: Big Obsidian Flow is a concessionaire-run fee site in Newberry National Volcanic Monument: $5 per vehicle per day, or a Northwest Forest Pass ($30 annual) or Interagency pass. Commercial vehicles pay $25 to $100 depending on passenger count. No permit is needed to walk the trail.
A Short Loop on Volcanic Glass
The Forest Service describes a one-mile interpretive trail that climbs up and onto the flow of obsidian and pumice. AllTrails maps the loop at 0.7 miles with 203 feet of gain and rates it moderate, mostly for the climb onto the flow and the uneven footing; the average visit is under half an hour. Signs along the way explain the eruption, the plants and animals that have moved back in, and how people have used the obsidian.
Getting to Newberry Caldera
From Bend, the Forest Service routes you 24 miles south on Highway 97 and then 15 miles east on Paulina Lake Road (County Road 21) into the monument. The site has picnic tables and a vault toilet. In summer rangers give talks at the Big Obsidian Flow Amphitheater; the Paulina Visitor Center, which posts the schedule, closed for the 2026 season in late September. On the day this page was checked the Forest Service listed Paulina Lake Road as open.
Why Dogs Should Stay Home
The Forest Service page for this site doesn't list a pet rule, but AllTrails and Visit Central Oregon both advise against bringing dogs because nearly the whole trail is sharp, jagged obsidian that can cut paws and heats up in the sun. Plan this stop for a day when the dog can stay with someone at the picnic area or at home. Sturdy closed-toe shoes matter for people, too; sandals and sharp glass don't mix.
When to Go
The Forest Service lists the season as June to late fall and allows day use only. In winter the caldera turns into a snowmobile and ski destination, and the Forest Service points winter visitors to 10 Mile Sno-Park on County Road 21, where an Oregon Sno-Park permit is required from November 1 through April 30. On summer afternoons the dark glass gets hot, so a morning or evening visit is more comfortable for people as well.
Hiking tips for Big Obsidian Flow Trail
- Wear closed-toe shoes with thick soles; the obsidian edges are sharp.
- Stay on the trail and leave the glass where it lies.
- Visit early or late on hot days; the dark flow holds heat.
- Combine it with Paulina Falls or a lakeshore walk for a full caldera day.
- Check the Forest Service road status before driving up in late fall.
Nearby trails to explore
- Paulina Peak Trail
- Benham Falls Trail
- Pilot Butte Nature Trail
Hike this trail with TrailMates
The Big Obsidian Flow is a short stop on a full day in Newberry Crater, and the drive is better shared. Use TrailMates to find Bend hikers planning a caldera day. Download TrailMates on the App Store or Google Play to join a group.