Salmon Hot Spring

Lemhi County, Idaho · Near Salmon
45.0950°N, 113.8360°W · 4,920 ft
113°F 34°F air · Good soaking weather 4,920 ft Roadside Camping nearby (8.0 mi)

Salmon Hot Spring sits beside an unnamed road in Lemhi County, six miles or so from the town of Salmon. Hot water at the source, beyond soaking comfort, so it needs testing. Ownership and public access are not recorded, which is worth settling first. Williams Lake Campground is about eight miles away.

Location

Close to five thousand feet, with moderate precipitation and five or six feet of snow each season. The approach amounts to crossing a hundred feet of ground. Neither land owner nor management unit appears in the file, and the record is silent on the surroundings. Williams Lake Campground is the camping on record, eight miles out.

The record favors a winter visit. Test the outlet before anything else; it runs hot. For camping the record gives Williams Lake Campground. No fee listed. The chemistry is from 1980. Ask locally who owns the ground, since access is not recorded. The temperature figure dates back decades, so verify it on the spot.

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 Salmon Hot Spring.

Aerial view of the ground around Salmon Hot Spring LiDAR bare-earth view of the same ground around Salmon 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
Hillside
The spring sits on a steep slope that climbs to the south.
Highest ground nearby
280 ft above the spring
Within a quarter mile, to the south
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
99 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 45% 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
21°
Jan
24°
Feb
33°
Mar
40°
Apr
50°
May
60°
Jun
70°
Jul
69°
Aug
59°
Sep
44°
Oct
29°
Nov
19°
Dec
Annual Precip: 18.9 in Annual Snow: 65.7 in
Best Time to Visit
December Air 19°F · Water 113°F · +94° contrast
January Air 21°F · Water 113°F · +92° contrast
February Air 24°F · Water 113°F · +89° contrast
December offers 51°F more contrast than July
Current Conditions
34°F
Clear N 0.0 mph 86% Good soaking weather
Today 69° Low 44° Sunny
Spring is +44° warmer
Wednesday 73° Low 48° Sunny
Spring is +40° warmer
Thursday 71° Low 48° Light Rain Likely then Showers And Thunderstorms Likely 70% precip
Spring is +42° warmer
Friday 65° Low 45° Light Rain Likely then Chance Showers And Thunderstorms 57% precip
Spring is +48° warmer
Saturday 69° Low 46° Sunny 11% precip
Spring is +44° warmer
Water Chemistry Sampled 1980-08-07

The water at Salmon Hot Spring is neutral (pH 7.1).

pH 7.1 Neutral
pH influences mineral absorption through skin
Calcium 21 mg/L
May support bone density and joint health
Magnesium 10 mg/L
Known for muscle relaxation and stress relief
Sodium 190 mg/L
Supports circulation and skin hydration
Sulfate 31 mg/L
Traditionally used for skin conditions and inflammation
Chloride 49 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
Williams Lake Campground 8.0 mi away

This campground has 11 sites near Williams Lake. Opportunities abound to hike or ride into the Salmon-Challis National Forest or to fish in the nearby lake or creek. The lake can be accessed at the Forest Service boat ramp and day-use area.

Reserve on Recreation.gov →
Temperature
113°F
Warm Hot Boiling
Water Temp 113°F (45°C)
Avg Air Temp 43°F
Above Ambient +70°F
Great soaking conditions September
Access
Road Access Roadside
Distance to Road 100 ft
Frequently Asked Questions
What is the water temperature at Salmon Hot Spring?
Salmon Hot Spring has a water temperature of 113°F (45°C). This is considered a hot spring, well above body temperature.
Where is Salmon Hot Spring located?
Salmon Hot Spring is located in Lemhi County, Idaho at 4,920 feet elevation, near Salmon. Coordinates: 45.0950°N, 113.8360°W.
How do I get to Salmon Hot Spring?
Salmon Hot Spring has Roadside road access (100 ft from the road).
Can I camp near Salmon Hot Spring?
Yes, Williams Lake Campground is located nearby (8.0 miles away).
What minerals are in the water at Salmon Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 7.1 (neutral).
Is it safe to soak at Salmon Hot Spring?
With care. At 113°F Salmon 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.
Sources: USGS NWIS