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Big Obsidian Flow Loop Hike

From Oregon Hikers Field Guide

Lost Lake at the edge of the Big Obsidian Flow, Newberry Caldera (bobcat)
Scree edge, Big Obsidian Flow, Newberry Caldera (bobcat)
On the Big Obsidian Flow, Newberry Caldera (bobcat)
Shady bench, Big Obsidian Flow (bobcat)
The interpretive loop at the Big Obsidian Flow (not a GPS Track) (bobcat) Courtesy: USFS/Caltopo
  • Start point: Big Obsidian Flow TrailheadRoad.JPG
  • End Point: Big Obsidian Flow
  • Trail Log:
  • Hike Type: Lollipop loop
  • Distance: 0.8 miles
  • Elevation gain: 200 feet
  • High Point: 6,600 feet
  • Difficulty: Easy
  • Seasons: Mid-spring into fall
  • Family Friendly: Yes
  • Backpackable: No
  • Crowded: Yes



The one-square-mile Big Obsidian Flow is one of the most memorable features in a landscape of outstanding volcanic features in the Newberry National Volcanic Monument. This lava flow, composed of black glass (obsidian) and pumice, is the youngest in Oregon and issued forth only 1,300 years ago. The lava erupted from a magma chamber two to four miles deep at a temperature of 1600 degrees Fahrenheit. At first, the eruption was gas-charged and explosive. Later, the lava emissions slowed to a 100-foot-high silica-infused creep that produced a thick dome over the vent. Three layers emerged: white pumice from the frothing of the lava's surface; glassy obsidian in the middle; and gray pumice charged with huge bubbles on the bottom. Lighter pumice attempted to rise, while heavier obsidian tried to sink and a general mixing and shattering of liquid and solid components resulted in the fractured landscape you see today. Native Americans took full advantage of the natural resource and fashioned obsidian fragments into tools and weapons, such as spear and arrow heads. Note that collecting obsidian is forbidden within the Newberry National Volcanic Monument.

The lollipop loop to the Big Obsidian Flow Trail #3958A begins on the south side of the parking area. A paved trail reaches a flight of steel steps that takes you up to get views down to the base of the flow and the ponds that remain of Lost Lake. Interpretive signs along this trail detail the volcanic, human, and natural history of the Big Obsidian Flow. The first trail junction is with a short spur leading left. The second junction is the beginning of the loop, so go left here. You’ll soon get a view up to the looming prominence of Paulina Peak. At the top of the loop, a spur leads left to a bench, one of several along the trail. Paulina Lake glistens to the north. Note how whitebark pines have colonized the lava flow, establishing footholds where no other species can. Wind down through the black boulders, and go left at the junction which closes the loop to return to the Big Obsidian Flow Trailhead.

Fees, Regulations, etc.

  • Northwest Forest Pass (or America the Beautiful Pass) required
  • Restrooms, picnic area, interpretive trails
  • No dogs on the obsidian flow (sharp rocks)


  • Maps: Hike Finder
  • Newberry Caldera & Paulina Lakes (Maplets)
  • U.S. Department of Agriculture, Forest Service: Fort Rock Ranger District
  • U.S. Department of Agriculture, Forest Service: Deschutes National Forest
  • Adventure Maps: Bend, Oregon, Trail Map
  • National Geographic Trails Illustrated Map: Bend – Three Sisters

Trip Reports

Related Discussions / Q&A

Guidebooks that cover this destination

  • 100 Hikes/Travel Guide: Eastern Oregon by William L. Sullivan
  • Hiking Oregon’s Geology by Ellen Morris Bishop
  • Day Hiking: Bend and Central Oregon by Brittany Manwill
  • Best Easy Day Hikes: Bend & Central Oregon by Lizann Dunegan
  • Best Hikes Near Bend by Lizann Dunegan
  • Hiking Oregon by Lizann Dunegan
  • Bend, Overall by Scott Cook
  • Day Hikes in Central Oregon by Jan Siegrist
  • Hiking Central Oregon & Beyond by Virginia Meissner
  • Oregon & Washington: 50 Hikes With Kids by Wendy Gorton
  • Best Hikes With Kids: Oregon by Bonnie Henderson & Zach Urness
  • Central Oregon: Walks, Hikes & Strolls for Mature Folks by Marsha Johnson
  • Trail Running: Bend and Central Oregon by Lucas Alberg
  • Oregon's Southern Cascades: Camping & Hiking by Tom Stienstra & Sean Patrick Hill
  • Oregon Hiking by Sean Patrick Hill
  • Pacific Northwest Hiking by Scott Leonard & Sean Patrick Hill

More Links

Page Contributors

Oregon Hikers Field Guide is built as a collaborative effort by its user community. While we make every effort to fact-check, information found here should be considered anecdotal. You should cross-check against other references before planning a hike. Trail routing and conditions are subject to change. Please contact us if you notice errors on this page.

Hiking is a potentially risky activity, and the entire risk for users of this field guide is assumed by the user, and in no event shall Trailkeepers of Oregon be liable for any injury or damages suffered as a result of relying on content in this field guide. All content posted on the field guide becomes the property of Trailkeepers of Oregon, and may not be used without permission.