Three Sisters Wilderness, OR
Obsidian Summit Trail
Distance
9.6 mi
Elev. Gain
+1,820 ft
Time
4–5 hrs
Difficulty
Moderate
ModerateVolcanic pumice, obsidian fieldsDog-friendlyBest: Late June – October
A volcanic plateau hike through otherworldly obsidian lava fields and lodgepole pine forest that emerges onto a pumice summit with direct views of South Sister. The volcanic geology is unlike anything else in the Oregon Cascades — chunks of natural glass glitter in the trail.
Highlights
- Native obsidian field — glass shards litter the trail naturally
- Direct summit view of South Sister (10,358 ft)
- Sparse lodgepole forest typical of high-elevation volcanic soils
- Vivid sunset alpenglow on clear evenings
Trail tips
- →A Northwest Forest Pass is required; purchase at Recreation.gov
- →Obsidian is protected — do not collect specimens
- →Pumice is deceptively tiring underfoot; pace yourself on the ascent
- →Lightning risk on open plateau — turn around if afternoon clouds build
out-and-backvolcanicalpineviewsdog-friendly
Done this trail?
Log your hike — date, distance, and notes — in your private SnowyKrish logbook.
Open my logbook →