Lower Loon Creek Hot Spring

Also known as: Loon Creek Hot Spring
Custer County, Idaho · Near Challis
44.7990°N, 114.8060°W · 4,094 ft
120°F 36°F air · Good soaking weather 4,094 ft Open Short Walk US Forest Service Camping nearby (20.8 mi)

Lower Loon Creek Hot Spring, which OpenStreetMap lists as Loon Creek Hot Spring, is on the Challis National Forest in Custer County, thirty-five miles from Challis. It comes out hot, above soaking temperature at the source. Access is open. It is under half a mile from the nearest road, and there is a photo on file.

Location

Under half a mile on foot from a road that has no name in our data. Elevation is around four thousand feet, with heavy snow, eight or nine feet a year, and moderate precipitation. Yellowjacket Guard Station is twenty-one miles distant, the nearest camping on record. National Forest land, no wilderness tag attached.

Our chart shows midwinter as the dry season, but snow will be the limiting factor then. Let it cool. Test it with a hand before anything else goes in. Chemistry from a 1980 survey. Listed as open. Nobody has recorded a fee.

History of Lower Loon Creek Hot Spring

In June 1980 the USGS sampled the spring. OpenStreetMap drops the Lower from the name and calls it Loon Creek Hot Spring.

Terrain

Aircraft with laser scanners measured this ground to within inches. The scan strips out trees and buildings, leaving the bare shape of the land around Lower Loon Creek Hot Spring.

Aerial view of the ground around Lower Loon Creek Hot Spring LiDAR bare-earth view of the same ground around Lower Loon Creek Hot Spring
Aerial LiDAR bare earth

Drag the handle to compare the two views. The orange dot marks the spring, in a frame about three quarters of a mile wide.

Setting
Canyon floor
Steep ground climbs away on both sides of the spring.
Highest ground nearby
841 ft above the spring
Within a quarter mile, to the west
Cross-section through the spring

A slice through the ground from southwest to northeast, about 0.6 miles end to end.

Elevation data: USGS 3D Elevation Program. Aerial imagery: USGS The National Map. Public domain.

Heat Below
126 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 77% of the springs on this site.

Heat flow measures the warmth working its way up through the ground from deep inside the earth. Where it runs high, rain and snowmelt that seep down through cracks in the rock come back up hot.

Heat flow estimate: Stanford Thermal Earth Model (Aljubran & Horne, 2024), CC BY 4.0.

Monthly Climate
28°
Jan
30°
Feb
37°
Mar
42°
Apr
51°
May
62°
Jun
73°
Jul
72°
Aug
62°
Sep
47°
Oct
33°
Nov
25°
Dec
Annual Precip: 22.5 in Annual Snow: 101.9 in
Best Time to Visit
December Air 25°F · Water 120°F · +95° contrast
January Air 28°F · Water 120°F · +92° contrast
February Air 30°F · Water 120°F · +90° contrast
December offers 48°F more contrast than July
Current Conditions
36°F
Clear N 0.0 mph 75% Good soaking weather
Today 75° Low 46° Sunny
Spring is +45° warmer
Wednesday 80° Low 50° Sunny 11% precip
Spring is +40° warmer
Thursday 75° Low 49° Rain then Showers And Thunderstorms 81% precip
Spring is +45° warmer
Friday 72° Low 47° Chance Light Rain then Chance Showers And Thunderstorms 52% precip
Spring is +48° warmer
Saturday 76° Low 47° Sunny 10% precip
Spring is +44° warmer
Water Chemistry Sampled 1980-06-28

The water at Lower Loon Creek Hot Spring is alkaline (pH 9.0).

pH 9.0 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Sodium 94 mg/L
Supports circulation and skin hydration
Sulfate 50 mg/L
Traditionally used for skin conditions and inflammation
Chloride 11 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
Yellowjacket Guard Station 20.8 mi away

Overview Yellowjacket Guard Station is a historic Forest Service Ranger Station and Work Center. Originally constructed in 1925 and remodeled in 1934 by the Civilian Conservation Corps, the structure is eligible for listing on the National Register of Historic Places. Recreation Hikers, horseback riders, mountain bikers and off-road enthusiasts will find many trails in the surrounding area. Hunting is also a popular activity. Click here for an Idaho OHV safety messageFacilities The spacious...

Reservable Yes
Reserve on Recreation.gov →
Temperature
120°F
Warm Hot Boiling
Water Temp 120°F (49°C)
Avg Air Temp 47°F
Above Ambient +73°F
Great soaking conditions September
Access
Open
Road Access Short Walk
Distance to Road 0.4 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Challis National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Lower Loon Creek Hot Spring?
Lower Loon Creek Hot Spring has a water temperature of 120°F (49°C). This is considered a hot spring, well above body temperature.
Where is Lower Loon Creek Hot Spring located?
Lower Loon Creek Hot Spring is located in Custer County, Idaho at 4,094 feet elevation, near Challis. Coordinates: 44.7990°N, 114.8060°W.
How do I get to Lower Loon Creek Hot Spring?
Lower Loon Creek Hot Spring has Short Walk road access (0.4 mi from the road).
Is Lower Loon Creek Hot Spring free to visit?
Lower Loon Creek Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Lower Loon Creek Hot Spring?
Yes, Yellowjacket Guard Station is located nearby (20.8 miles away).
What minerals are in the water at Lower Loon Creek Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.0 (alkaline).
Is it safe to soak at Lower Loon Creek Hot Spring?
With care. At 120°F Lower Loon Creek Hot Spring is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.