Obsidian Flow & Paulina Peak
0.8-mile loop 450 feet elevation gain Open late June through October Difficult (to Paulina Peak) 9.6 miles one way (with shuttle) 2260 feet elevation gain Open mid-July through October
Left: Obsidian Flow at Newberry Caldera
In the ruined shell of Mt. Newberry, an easy nature trail tours the freshest lava flow in Central Oregon, a hill of shiny black obsidian glass. If you’d like to leave the tourists behind, hike a tougher trail around the obsidian flow to the desert of Pumice Flat, and up to the views atop cliff-edged Paulina Peak.
The Newberry Volcano is probably Oregon’s strangest peak. It’s the latest protrusion of a geologic “hot spot” that’s been moving westward from Idaho for 10 million years, leaving a string of lava flows and volcanic buttes in its wake. Geologists theorize that North America’s shearing collision with the Pacific plate has been stretching Eastern Oregon diagonally all this time, and lava has been leaking through the shifting cracks.
All that lava has made Newberry the state’s most massive volcano, measured by volume. Countless thin basalt lava flows have built up its 25-mile-wide shield-shaped bulk over the past half million years. Like many aging volcanoes, Mt. Newberry’s eruptions gradually contained more silica, making the lava thicker, glassier, and more explosive. The entire mountaintop has collapsed in Crater Lake fashion at least twice, leaving a gaping, 6-mile-wide caldera. The giant lake that once filled that caldera has since been split in two by lava flows. The largest of these flows, the Big Obsidian Flow, poured more than a square mile of black glass into the caldera just 1300 years ago.
Start by driving south...