Stanley Hot Spring

Custer County, Idaho · Near Challis
44.2240°N, 114.9290°W · 6,220 ft
106°F 24°F air · Good soaking weather 6,220 ft Open Roadside US Forest Service Camping nearby (3.5 mi)

Stanley Hot Spring sits within about seventy feet of the Salmon River Scenic Byway, on Challis National Forest ground in Custer County, about forty miles from Challis, the nearest town on file. Measured hot in 1972, only a notch over comfortable soaking. Open to the public. A picture is on record.

Location

Road access is as easy as it gets, the byway passing close enough that there is no walk worth mentioning. High country, averaging around forty through the year, with a dozen feet of snow and a fair amount of rain the rest of the time. Land belongs to the Forest Service.

Sunny Gulch Campground sits three and a half miles off. Winter is listed as the time to go, and with twelve feet of snow the byway's condition is the first thing to check. The temperature reading is from 1972, so treat it as a rough guide. Alkaline water, sampled the same year.

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 Stanley Hot Spring.

Aerial view of the ground around Stanley Hot Spring LiDAR bare-earth view of the same ground around Stanley 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
Gentle slope
The ground tilts gently up to the west.
Highest ground nearby
146 ft above the spring
Within a quarter mile, to the west
Cross-section through the spring

A slice through the ground from west to east, about 0.6 miles end to end.

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

Heat Below
142 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 90% 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
22°
Jan
24°
Feb
30°
Mar
35°
Apr
43°
May
53°
Jun
65°
Jul
64°
Aug
54°
Sep
39°
Oct
27°
Nov
19°
Dec
Annual Precip: 27.3 in Annual Snow: 146.4 in
Best Time to Visit
December Air 19°F · Water 106°F · +87° contrast
January Air 22°F · Water 106°F · +84° contrast
February Air 24°F · Water 106°F · +83° contrast
December offers 46°F more contrast than July
Current Conditions
24°F
S 12.1 mph 91% Good soaking weather
Today 70° Low 28° Sunny
Spring is +36° warmer
Wednesday 75° Low 34° Sunny 6% precip
Spring is +31° warmer
Thursday 69° Low 32° Chance Light Rain then Showers And Thunderstorms 82% precip
Spring is +37° warmer
Friday 68° Low 29° Chance Light Rain 35% precip
Spring is +38° warmer
Saturday 71° Low 30° Sunny 9% precip
Spring is +35° warmer
Water Chemistry Sampled 1972-07-12

The water at Stanley Hot Spring is alkaline (pH 8.8).

pH 8.8 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 60 mg/L
Supports circulation and skin hydration
Sulfate 31 mg/L
Traditionally used for skin conditions and inflammation
Chloride 5 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
Sunny Gulch Campground 3.5 mi away

Overview Sunny Gulch Campground sits along the shores of Salmon River in the forests of central Idaho. Recreation Excellent fishing is right out your back door on the Salmon River, with rainbow trout, Westslope cutthroat trout and occasional hybrid cutbows and bull trout available. Sunny Gulch lies in the heart of the Sawtooth National Recreation Area. A myriad of excellent hiking and biking opportunities are available, and an estimated 750 miles of trails crisscross the valley and surround...

Reservable Yes
Reserve on Recreation.gov →
Mile-High Advisory 6,220 ft

Stanley Hot Spring sits at 6,220 feet above sea level, way above the mile-high mark. You may not feel the altitude strongly, but hot water still dehydrates you faster at elevation. UV is about 25% stronger than at sea level, so bring sunscreen and drink more water than you normally would.

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Temperature
106°F
Warm Hot Boiling
Water Temp 106°F (41°C)
Avg Air Temp 40°F
Above Ambient +66°F
Great soaking conditions September
Access
Open
Road Access Roadside
Nearest Road Salmon River Scenic Byway
Distance to Road 66 ft
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 Stanley Hot Spring?
Stanley Hot Spring has a water temperature of 106°F (41°C). This is considered a hot spring, well above body temperature.
Where is Stanley Hot Spring located?
Stanley Hot Spring is located in Custer County, Idaho at 6,220 feet elevation, near Challis. Coordinates: 44.2240°N, 114.9290°W.
How do I get to Stanley Hot Spring?
Stanley Hot Spring has Roadside road access, with the nearest road being Salmon River Scenic Byway (66 ft from the road).
Is Stanley Hot Spring free to visit?
Stanley Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Stanley Hot Spring?
Yes, Sunny Gulch Campground is located nearby (3.5 miles away).
What minerals are in the water at Stanley Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 8.8 (alkaline).