Ninemeyer Hot Springs
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
Ninemeyer Hot Springs is a primitive hot spring listed near Idaho City, Idaho. No soak temperature is on record. See the visit fact sheet.
Current status
A very hot (~169F source) spring on the far bank of the Middle Fork Boise River directly across from Ninemeyer Campground (~mile 38 on FS-268 near Atlanta); soaking is only possible after fording the river at low water — roughly late July through November — and the long Middle Fork Boise River Road approach is rough washboard that effectively closes in winter.
Checked September 2026 · based on recent visitor reports · 6 sources ↓
Staying overnight?
Stay in Idaho City for its managed soaking venue.
Idaho City is about 14 mi from the spring (straight line).
We may earn a commission from bookings through these links, at no extra cost to you.
Before you go
- Status: Open — last verified below — confirm via Recreation.gov — Ninemeyer Campground (no amenities due to wildfire; FS-268; seasonal road).
- Cost: Reported free access — fees and permits can change, confirm before visiting.
- Getting there: No verified hike distance on record — confirm the route and road conditions.
- Water: No soak temperature on record — always test the water before entering.
- Rules: Reported clothing-optional; pets reported not allowed — confirm current rules.
- Conditions: check weather, fire closures, and land-manager alerts the week you go — mountain access changes seasonally.
- Reservations/permits: None — Boise National Forest, no fee. Check road conditions with Mountain Home Ranger District (208-587-7961) before driving.
- Best time to go: Late July–November when river levels allow a safe ford; mid-May through late September for reliable road weather. Avoid spring runoff entirely.
- Clothing reality: No official policy (undeveloped Boise NF site); remote, lightly visited — clothing-optional in practice; swimsuits common given riverside visibility from the campground.
- Cell service: none — download maps and tell someone your plan.
- Accessibility: Requires an unbridged river ford plus rocky terrain — not accessible.
- Requires fording the Middle Fork Boise River — only advised at low water, roughly late July to November; in spring/early summer you just look at the steam from the far bank
- Source ~169F (76C) — scalding; user-built rock/sand-bottom pools form only in late season where hot meets cold river water
- At the right level it is 'like a heated swimming hole in the middle of the Boise River' (Idaho Statesman); too low and it is a thermal wading pool
- Ninemeyer Campground (8 sites, no fee, first-come) has NO amenities post-wildfire — no water, no developed fire rings; Stage 1 fire restrictions = no fires
- Middle Fork Boise River Road (FS-268) is a long, rough washboard gravel route — allow hours; winter snow closes most routes into Atlanta
- Several other soakable springs line the same corridor (Powerplant, Chattanooga, Greylock, Granite Creek, Loftus) — worth combining
- No cell service; nearest services in tiny seasonal Atlanta
- Hazard: River ford — swift, cold, potentially chest-deep; dangerous except at late-season low water
- Hazard: 169F scalding source; unstable user-built pools with hot spots
- Hazard: Post-wildfire burn area (2016 Pioneer Fire footprint): hazard trees, ash, no campground amenities
- Hazard: Rough remote road — washboard, narrow shelf sections; fatalities noted on Atlanta-area roads
- Hazard: Black bears in corridor; store food properly
About this spring
GNIS-catalogued springs on Boise NF land next to Ninemeyer Campground on the Middle Fork Boise River — a huge scalding flow (~169-173°F) cascades down a hillside building a mineral mound; user-built soaking pockets form at the river's edge where hot and cold mix. Source ~170°F — severe burn hazard. River ford only safe in late-season low water.
Ninemeyer Hot Springs pours one of the largest thermal flows on the Middle Fork Boise River corridor: water measured by the USGS at 168.8°F in August 1982 — alkaline (pH 9.6) with 245 mg/L dissolved solids — cascades from multiple hillside seeps across the river from Ninemeyer Campground on FS Road 268; other observers have logged up to ~173°F. Decades of mineral deposition have built a mound that juts out over the river, spilling scalding water into the cold flow.
Soaking happens only in small, user-built rocky pockets at the river's edge where the two waters mix — and only when the river can be safely forded, typically late July through November; at higher water the site is visible-but-unreachable steam. The Boise National Forest campground beside it lost its amenities to wildfire and has no developed fire rings. Companion corridor springs — Loftus, Vaughn and Smith Cabin — lie within a few miles downstream.
Directions & trailhead access
Middle Fork Boise River Rd (FS 268) to Ninemeyer Campground; pools across the river — ford only advisable at low water (late Jul-Nov).
Idaho geothermal context
Idaho's thermal water rides the old track of the Yellowstone hotspot across the Snake River Plain and surfaces along faults in the surrounding mountains. Many of the best soaks are roadside or river-access pools inside national forests — including springs that only emerge when river levels drop. Backcountry sites demand real navigation skills and long dirt-road drives.
What a primitive site means here
Primitive springs have no facilities: no changing rooms, no trash service, often no maintained road to the pool. Expect natural rock or gravel bottoms, water temperature that varies by spot and season, and other visitors who may treat the site informally. Pack out everything you bring, test the water before entering, and leave the pool cleaner than you found it.
Best time to visit
Year-Round (Best: May – October)Pool temperatures and access can change with weather and season. Outdoor ambient temperatures fluctuate significantly across Idaho. Late spring through autumn offers the most comfortable road access.
Fact sheet
| Reported soak temp | Not reported |
|---|---|
| Source temp (historical) | 169°F |
| Trail access | Recorded coordinates — access unverified |
| Access fee | Reported free — verify locally |
| Clothing policy | Reported clothing-optional |
| Pet policy | Reported no pets |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | Recreation.gov — Ninemeyer Campground (no amenities due to wildfire; FS-268; seasonal road) |
Ninemeyer Hot Springs FAQ
Is Ninemeyer Hot Springs open right now?
A very hot (~169F source) spring on the far bank of the Middle Fork Boise River directly across from Ninemeyer Campground (~mile 38 on FS-268 near Atlanta); soaking is only possible after fording the river at low water — roughly late July through November — and the long Middle Fork Boise River Road approach is rough washboard that effectively closes in winter. (Status based on recent visitor reports, last checked September 2026.)
Is Ninemeyer Hot Springs free?
Ninemeyer Hot Springs is listed as free to access in Elmore County, Idaho. Fees and rules change — verify current status with the land manager before visiting.
What temperature is Ninemeyer Hot Springs?
No soak temperature is on record for Ninemeyer Hot Springs; the geothermal source is reported around 169°F. Always test water temperature before entering.
Is Ninemeyer Hot Springs clothing optional?
Ninemeyer Hot Springs is listed as traditionally clothing-optional in directory records. Confirm current rules before visiting, as policies change.
How do you access Ninemeyer Hot Springs?
Ninemeyer Hot Springs is on public land — verify current road access, fees and rules with the land manager before visiting.
Where to stay in Idaho City
Stay in Idaho City for its managed soaking venue. Remote Middle Fork Boise River springs require a separate road plan.
Idaho City is about 14 mi from the spring (straight line).
We may earn a commission from bookings through these links, at no extra cost to you.
Sources & references
- Recreation.gov — Ninemeyer Campground (no amenities due to wildfire; FS-268; seasonal road) — official · 2026-09
- Idaho Statesman — less-used camping near Boise (Ninemeyer = heated swimming hole at right river level) — news · 2017-06
- IdahoHotSprings.com — Ninemeyer page (user-built pools, ford late July–Nov) — community · 2003-06
- Ordealist — Atlanta Road / Middle Fork Boise River guide (seasonal closure Nov–May/Jun, high clearance upper sections) — community · 2024
- InciWeb — Boise NF Middle Fork Complex fire closure updates (Aug–Oct 2024) — official · 2024-10
Additional references for this record; a source link does not guarantee current conditions.
Details above were verified against the named sources on their listed dates — conditions change, so recheck before traveling. · How we verify our data · Report a correction
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