Upper Loon Hot Springs

Upper Loon Hot Springs is a complex of four separate hot spring sources strung along the Loon Creek Trail in the Frank Church–River of No Return Wilderness, passed in consecutive order as you trek up Loon Creek toward Warm Springs Creek. With everything from a two-person soaker to a 10–15 person pool fed by a hot waterfall, it’s one of the finest backpacking soaks in Idaho — reachable only in a short summer-to-fall window.

The Pools

All four sources have rock-walled pools with sand, gravel, and rock bottoms. Upper Loon #1 (“None Too Soon”) is a small two-seater at 101°F. Upper Loon #2 is a medium, four-person soaker whose main pool runs hot — 115–120°F, with a bucket on site for tempering; its other pools run too cool. Upper Loon #3 (“Crescent Moon”) is the glory: a 10–15 person pool fed by a hot waterfall, at 90–98°F depending on where you sit. Upper Loon #4 holds two stagnant, low-flow, algae-laden pools that are not suitable for soaking. Owen Cabin Hot Springs lies just beyond.

Seasonal Notes

The access road to the Loon Creek Trailhead is open only from July through October — the whole Loon Creek corridor, Upper Loon included, is a summer-to-fall trip.

Camping

A sweet campsite next to Upper Loon #2 sits beside an old cabin with a partially collapsed roof: room for 2–5 tents, a very nice fire pit with custom benches (one bench is supported by large gears from old mining equipment), and the hot springs a few paces away. Another semi-large site just beyond, near #3, is also nice but lacks shade.

Upper Loon Hot Springs in Idaho