About this campground
These undeveloped trails offer scenic solitude; there is a short 0.5 mile loop trail and a 4.5 mile trail to the main vent of the Hell's Half Acre flow. Trail routes are marked with poles across lava. A picnic area, fire ring and portable toilets are located at the trail-head. This is treacherous rocky terrain and proper footwear is advised. It also gets very hot and there is little to no shade so proper sun protection and water is advised.
Getting there
From Idaho Falls, travel west on Highway 20 to mile marker 287. Continue 0.3 miles until you see a sign for "Lava Trail." Turn left onto the gravel road (staying left at the fork) and continue one-quarter mile to the trailhead.
Activities
- HIKING
- WILDLIFE VIEWING
Nearby federal campgrounds
- South Fork of the Snake River: Menan Boat AccessSouth Fork of The Snake27 mi
- Big Southern ButteBureau of Land Management31 mi
- South Fork of the Snake River: Lorenzo Boat AccessSouth Fork of The Snake31 mi
- Wolverine CanyonBureau of Land Management31 mi
- South Fork of the Snake River: Byington Boat AccessSouth Fork of The Snake39 mi
- Egin Lakes Campground/Day Use AreaBureau of Land Management40 mi
Explore more Idaho camping
Twenty Mile Trail doesn't take campsite reservations — but plenty of nearby Idaho campgrounds do, and we'll alert you the moment a sold-out site opens up.
Browse Idaho camping →Details from Recreation.gov's official RIDB catalog. Conditions change — confirm with the managing office before you go. Not affiliated with Recreation.gov or any federal agency.