Can you reserve a site at Twenty Mile Trail?

No. Twenty Mile Trail is not reservable through Recreation.gov, so sites are first-come, first-served or booked elsewhere.

Twenty Mile Trail

Facility · Idaho ·

Managed by the Bureau of Land Management

Upper Snake Field Office (Bureau of Land Management ID) · Open Access

5,116 ft
Elevation

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.

43.55694, -112.44500 · 43°33'25.0"N 112°26'42.0"W

Directions (Google Maps) · Directions (Apple Maps)

Typical weather

Typically 87°F in Jul, down to 29°F in Jan.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
High °F	29	34	47	58	67	76	87	86	75	59	43	30
Low °F	12	16	25	31	38	45	49	48	41	31	22	13
Precip in	0.7	0.6	0.8	1.0	1.6	1.1	0.5	0.6	1.0	0.9	0.7	0.8

1991–2020 averages from the nearest NOAA station, 19.1 mi away — not measured at the facility itself, and elevation can make a real difference over that distance.

Map

Member photos

Add a photo

Common questions about Twenty Mile Trail

Can you reserve a site at Twenty Mile Trail?: No. Twenty Mile Trail is not reservable through Recreation.gov, so sites are first-come, first-served or booked elsewhere.

Camping near Twenty Mile Trail

Egin Lakes Campground/Day Use Area 40.4 mi · Campground · we watch it
Table Rock 43.1 mi · Campground · we watch it
South Fork of the Snake River: Menan Boat Access 26.9 mi · Facility
South Fork of the Snake River: Lorenzo Boat Access 30.8 mi · Facility
Wolverine Canyon 30.9 mi · Facility
Big Southern Butte 31 mi · Facility
South Fork of the Snake River: Byington Boat Access 39.3 mi · Facility
Kelly Island Campground 39.6 mi · Campground
Trail Creek Bridge Campground 39.9 mi · Campground
Stinking Springs ATV and Mountain Biking Trail 41.3 mi · Facility
Wolf Flats Recreation Area 42 mi · Facility
Morgans Bridge Campground 43.1 mi · Campground

Comments

Contact

Recreation.gov last updated this record on 2026-02-25.

Facility information and photographs from Recreation.gov (RIDB). SpotOpened is not affiliated with Recreation.gov or any federal agency.