South Twin via Gale River

The South Twin via Gale River is 10.5 miles round trip, starting at Gale River Trailhead. At AMC book time — half the distance in hours plus 30 minutes per 1,000 ft of climbing — that works out to roughly 5-9 hours. Most parties take longer than book time on rough or above-treeline terrain, in winter, or with a heavy pack.

The South Twin via Gale River climbs about 3,307 ft over 10.5 miles — an average of roughly 316 ft of gain per mile. That figure is cumulative ascent across the whole out-and-back, not the difference between the trailhead and the high point.

HikerNerd rates the South Twin via Gale River Difficult, scored with the Shenandoah difficulty formula — √(elevation gain × 2 × distance) — applied to its 10.5 miles and 3,307 ft of gain. The score measures physical effort only. Above-treeline exposure, water crossings, and winter conditions can make a moderate-rated route the hardest day of your year, so check current conditions before committing.

The South Twin via Gale River summits 1 named peak: South Twin Mountain.

The South Twin via Gale River starts at Gale River Trailhead. Check the trail alerts on this page before you drive — trailhead access and parking in the White Mountains change with closures and construction.