Big Southern Butte — Snake River Plain Volcanic Landmark Viewpoint

Big Southern Butte punches straight up out of the lava flats like it doesn’t belong there — because geologically, it kind of doesn’t. This rhyolite dome formed roughly 300,000 years ago and tops out around 7,560 feet, making it one of the most dramatic isolated summits on the Snake River Plain. From the BLM road on its flanks you get sweeping views of the volcanic terrain that defines this whole corridor — lava fields, cinder cones, and the distant Pioneers to the north. It’s a navigation anchor you’ll see from the moment you leave Idaho Falls heading west.

The BLM manages access roads around the butte. A rough two-track circles the base and a summit trail exists, but the road surface deteriorates fast after wet weather. High-clearance is strongly recommended. No facilities on site. This sits squarely on the corridor between Idaho Falls and Hells Half Acre — hard to miss, worth a stop.

700-ft rhyolite dome above the lava plain.