Idaho Hot Springs Loop: A Road Trip from Boise
Updated September 2026 · 15 stops · verified status on every stop
Idaho has the densest hot-springs concentration in the country, and the classic loop out of Boise strings together 15 soakable stops over roughly 600 miles: Lowman's famous pools on Hwy 21 (Kirkham, Pine Flats), Stanley's riverside soaks (Boat Box, Sunbeam), the hike-in terraces at Goldbug near Salmon, then McCall's resort row (Burgdorf, Gold Fork) on the return leg. Most are free or a few dollars; only the developed resorts need reservations — Burgdorf and The Springs book out weeks ahead. June–October is the reliable window.
The stops, in driving order
1. Terrace Lakes Resort Hot Springs PoolOpen
Start — ~50 mi north of Boise via Hwy 55 → Banks → Hwy 17 to Garden Valley
The soft opener: a year-round geothermal pool (90–100°F) at a public golf resort in Garden Valley — no booking, walk-in day use ~$15. Swap it for a pure-primitive start if you’d rather skip the resort feel.
2. The Springs (Idaho City)Reservation/permission
~30 mi — back to Banks, then up winding Hwy 21 to Idaho City
Idaho’s upscale developed soak: reservation-only 2.5-hour sessions (~$30), a big mineral pool plus private tubs. Closed Tuesdays/Wednesdays; Mon/Thu/Fri are adults-only. Book ahead — sessions cap out.
3. Pine Flats Hot SpringsOpen
~50 mi east on Hwy 21 toward Lowman, short walk from the campground
Riverside pools on the South Fork Payette with a warm waterfall pouring off the cliff above — ~0.25-mi walk, $5 day-use fee. The 138°F source means the upper pools can scald; test before you settle in. Road is seasonal — check winter access.
4. Kirkham Hot SpringsOpen
~10 mi east on Hwy 21 — the signed day-use site across the bridge
The icon of the loop: steam-curtain pools stepping down a hillside to the Payette River. Boise NF runs it day-use only (7am–9pm, gate locks), $5/vehicle. Go early on summer weekends — it fills. Spring runoff can submerge the riverside pools.
5. Bonneville Hot SpringsOpen
~19 mi east on Hwy 21, then a 0.25-mi trail from Bonneville Campground
A quiet primitive pool in Boise NF — the counterpart to Kirkham’s crowds. $5 self-pay day-use; reachable on foot year-round, though the walk runs ~1 mi longer when the campground road is snowed in.
6. Boat Box Hot SpringOpen
~45 mi — over Banner Summit on Hwy 21, then north on Hwy 75 to Stanley
A free roadside soak on the Salmon River 3.3 mi north of Stanley. The famous metal cauldron was washed away in 2023 flooding (reportedly relocated to Sunbeam), but the ~136°F spring still feeds riverbank pools. Test the pipe outlet — it scalded people before.
7. Sunbeam Hot SpringsOpen
~13 mi east on Hwy 75 — roadside, watch for the steam
User-built rock pools right on the Salmon River, plus the salvaged metal tubs and a viewing-only 1937 CCC bathhouse. The 160–180°F source mixes down to ~100–110°F — some inlets stay dangerously hot. River level controls the pools: spring runoff can drown them.
8. Challis Hot SpringsOpen
~35 mi northeast on Hwy 75 toward Challis
The comfortable midpoint: an Idaho State Parks unit with two untreated mineral pools on the Salmon River — $10/person day use, proper facilities, open year-round. The ~127°F source is flow-cooled, but hot spots linger near inlets.
9. Goldbug Hot SpringsOpen
~50 mi north on US-93 — trailhead just south of Salmon
The most-photographed soak in Idaho: terraced hillside pools reached by a ~4-mile round-trip hike gaining ~900 ft. Year-round, free — but the trailhead crosses a private-property easement, so follow posted rules (no camping within 500 ft, pack out) or access dies with it.
10. Sharkey Hot SpringsOpen
~15 mi — back south on 93, signed BLM turnoff
The most civilized primitive stop: BLM-built concrete pools (~103°F) with heated changing rooms and vault toilets, $3/person via recreation.gov or self-pay. Closed Wednesdays. Untreated water — rinse off after.
11. Burgdorf Hot SpringsReservation/permission
Long leg — ~140 mi west via US-93 → ID-95 → McCall, then 32 mi of forest road north
A 1860s rustic resort that feels like the frontier: reserved 2-hour soak blocks (~$20, book up to 90 days out), walk-ins turned away. Closed Wednesdays and through the Nov–Dec / Apr–May mud seasons when the forest road goes impassable.
12. Gold Fork Hot SpringsOpen
~45 mi south — back through McCall toward Donnelly
Six flow-through mineral pools (85–110°F) including a sand-bottom kids’ pool — the best family-friendly developed soak on the loop. $15/person, CASH OR CHECK ONLY, closed Tuesdays, 2-hour soak cap.
13. Trail Creek Hot SpringsOpen
~20 mi east on Warm Lake Rd — tiny pullout near milepost 60.6
Free year-round primitive pools on Trail Creek — a steep 0.1-mi path down from a blink-and-miss-it highway pullout. Scalding source water; watch footing on the descent.
14. Molly's Tubs (South Fork Plunge)Open
~25 mi — South Fork Salmon River Rd into Boise NF
The wild one: riverside springs where the Forest Service removed the namesake bathtubs in 2009 — visitors keep rebuilding rock pools and a piped tub. ~131°F source and near-boiling mud around seeps; test everything twice.
15. Rocky Canyon Hot SpringsOpen
~40 mi south — Middle Fork Payette, ~13 mi north of Crouch
A fitting finale: tiered rock pools (~105°F upper) that you reach by FORDING the Middle Fork Payette — easy in late summer, genuinely dangerous at high flow. If the river looks pushy, this one waits for another trip.
Plan the drive
Roads & seasons
The backbone is Hwy 55 → Hwy 21 (Ponderosa Pine Scenic Byway, winding and icy Oct–Apr) → Hwy 75 past the Sawtooths → US-93 to Salmon → ID-95/US-95 home via McCall. Paved all the way — the dirt is only at the springs themselves (Burgdorf’s 32-mi forest road is the big one; it closes in shoulder seasons). Check 511.idaho.gov before any leg in shoulder months.
Reservations & money
Book two things ahead: The Springs (Idaho City) — reservation-only sessions that cap out — and Burgdorf’s 2-hour soak blocks, released ~90 days out. Gold Fork is cash-or-check only ($15). Everything else is walk-up, and most of the primitive pools are free. USFS campgrounds cluster along Hwy 21 (Kirkham, Bonneville, Pine Flats) and around Stanley.
Honest cautions
Idaho’s sources run hot — 130–180°F at several inflow pipes; test every pool. Rocky Canyon requires a real river ford (skip it at high flow), Goldbug’s trailhead crosses private land (follow the rules or access dies), and spring runoff drowns the riverside pools. Skinnydipper near Boise is closed by BLM order through Feb 2027 — it’s not a stop, and entering is citable.
Idaho Hot Springs Loop FAQ
What is the best hot springs loop in Idaho?+
The classic loop runs Boise → Garden Valley → Lowman (Kirkham, Pine Flats, Bonneville) → Stanley (Boat Box, Sunbeam) → Salmon (Goldbug, Sharkey) → back west through McCall (Burgdorf, Gold Fork, Trail Creek) — roughly 600 miles and 15 stops over 4–5 days. It covers Idaho’s famous free primitive pools, three reservation resorts, and a state-park soak.
Are Idaho hot springs free?+
Mostly yes — Idaho has one of the best free-soak densities in the West. Boat Box, Sunbeam, Bonneville (with $5 parking), Trail Creek, Molly’s Tubs, Rocky Canyon and Goldbug are free or fee-box cheap. The Springs Idaho City (~$30), Burgdorf (~$20), Gold Fork ($15 cash only), Terrace Lakes (~$15), Challis ($10) and Sharkey ($3) charge admission.
Is Kirkham Hot Springs open?+
Yes — Boise National Forest runs Kirkham as a day-use site, 7am–9pm with a locking gate; $5/vehicle or an interagency pass. Park outside the gate and walk the bridge to the pools. Spring runoff can submerge the riverside pools, and summer weekends get crowded — arrive early.
Do you need reservations for Idaho hot springs?+
Only at the developed resorts. The Springs (Idaho City) is reservation-only with capped 2.5-hour sessions, and Burgdorf runs reserved 2-hour soak blocks that book out up to 90 days ahead — walk-ins get turned away. Everything else on the loop is walk-up: Kirkham, Gold Fork (cash/check only), Challis, Sharkey, and all the primitive pools.
When is the best time for an Idaho hot springs road trip?+
June through October is the reliable window — Hwy 21 and the forest roads are snowbound much of winter, and spring runoff (April–June) can flood riverside pools like Sunbeam, Boat Box and the Kirkham riverbank tubs. September–October is the sweet spot: roads open, crowds gone, rivers low enough for Rocky Canyon’s ford.
Can you do the Idaho loop in winter?+
Partially. Hwy 55 and ID-95 stay plowed, so Terrace Lakes, Gold Fork (check seasonal hours), and trailhead-reachable Goldbug remain possible — but Hwy 21 over Banner Summit sees heavy snow, Burgdorf closes Nov–Dec and Apr–May, and the forest-road springs are out. Winter visits need chains, check 511.idaho.gov, and treat every approach as weather-dependent.
Are Idaho hot springs clothing optional?+
At the primitive public-land pools, clothing-optional is customary — especially early mornings at Sunbeam, Boat Box and the hike-in springs. The developed resorts (The Springs, Burgdorf, Gold Fork, Challis, Terrace Lakes, Sharkey) require swimwear.
What about Skinnydipper Hot Springs?+
Skinnydipper — the famous Boise-area party spring — is CLOSED under a BLM order through February 14, 2027 after years of resource damage and a rockslide injury. It’s deliberately not a stop on this loop; entering is citable. Kirkham and Pine Flats fill the same "close to Boise" slot legally.
Sources & verification
Every stop's status pulls live from the same researched record as its detail page — verified against official sources where available, dated September 2026. Key references:
- Boise National Forest — Kirkham/Pine Flats/Bonneville recreation pages (official)
- Idaho State Parks — Land of the Yankee Fork (Challis Hot Springs) (official)
- BLM Idaho — Sharkey Hot Springs & Skinnydipper closure order (official)
- USFS Sawtooth NF & Salmon-Challis NF — trailhead/closure orders (official)
- The Springs Idaho City / Burgdorf / Gold Fork — operator sites (operator)
- Idaho Transportation Dept. — 511 road conditions (official)
Conditions change — each spring's detail page carries its own named sources and last-checked date. · How we verify · All Idaho springs · Springs near Boise