Sunbeam Hot Springs

Custer County, Idaho · Near Challis
44.2680°N, 114.7480°W · 6,160 ft
169°F 23°F air · Good soaking weather 6,160 ft Open Roadside US Forest Service Camping nearby (2.9 mi)
Very Hot Source, Use Extreme Caution

At 169°F, the source water at Sunbeam Hot Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking. Always test the water temperature before entering.

Way too hot to hold a hand in, that is Sunbeam Hot Springs at the source. It rises in Challis National Forest, Custer County, thirty miles or so down the Salmon River Scenic Byway from Challis, and the Forest Service has it open to the public. Anyone soaking has to let the water cool first. Dissolved solids are low for a hot spring. The water is strongly alkaline.

Location

The Salmon River Scenic Byway passes within about fifty yards, which makes this about as easy to reach as a hot spring gets. You are on national forest land at a bit over six thousand feet. Winters pile up a lot of snow here, and the climate is on the dry side the rest of the year.

The record flags December through February as the best months. Pole Flat Campground is about three miles away. The spring is at the roadside, so no walking to speak of. Treat the source as dangerous: at that temperature the water will burn skin on contact, and only where it has cooled should anyone think about getting in. The chemistry sample dates from late 1983.

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 Sunbeam Hot Springs.

Aerial view of the ground around Sunbeam Hot Springs LiDAR bare-earth view of the same ground around Sunbeam Hot Springs
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
623 ft above the spring
Within a quarter mile, to the north
Cross-section through the spring

A slice through the ground from north to south, about 0.6 miles end to end.

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

Heat Below
134 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 85% 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
44°
May
55°
Jun
66°
Jul
65°
Aug
55°
Sep
40°
Oct
28°
Nov
19°
Dec
Annual Precip: 23.9 in Annual Snow: 125.0 in
Best Time to Visit
December Air 19°F · Water 169°F · +150° contrast
January Air 22°F · Water 169°F · +147° contrast
February Air 24°F · Water 169°F · +145° contrast
December offers 47°F more contrast than July
Current Conditions
23°F
N 0.0 mph 92% Good soaking weather
Today 62° Low 35° Sunny
Spring is +107° warmer
Wednesday 67° Low 39° Sunny 7% precip
Spring is +102° warmer
Thursday 61° Low 37° Chance Light Rain then Showers And Thunderstorms 82% precip
Spring is +108° warmer
Friday 60° Low 35° Chance Light Rain 36% precip
Spring is +109° warmer
Saturday 64° Low 36° Sunny 10% precip
Spring is +105° warmer
Water Chemistry Sampled 1983-11-02

The water at Sunbeam Hot Springs is alkaline (pH 9.0) with 291 mg/L total dissolved solids.

pH 9.0 Alkaline
pH influences mineral absorption through skin
Higher mineral concentration for therapeutic soaking
Calcium 2 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 88 mg/L
Supports circulation and skin hydration
Sulfate 45 mg/L
Traditionally used for skin conditions and inflammation
Chloride 15 mg/L
Natural antiseptic with skin health benefits
Iron 20 µg/L
Iron-rich springs may support circulation
Where to Stay

Some links are affiliate links. We may earn a commission at no extra cost to you.

Nearby Camping
Pole Flat Campground 2.9 mi away

This campground is away from the main road and up the hill overlooking the river and the dredge ponds. Campsites include picnic tables tent pads fire rings with cooking grills. Campground amenities include a vault toilet and drinking water. Sites accommodate trailers and motorhomes up to 32 feet long.

Reserve on Recreation.gov →
Mile-High Advisory 6,160 ft

Sunbeam Hot Springs sits at 6,160 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.

As an Amazon Associate, we earn from qualifying purchases.

Temperature
169°F
Warm Hot Boiling
Water Temp 169°F (76°C)
Avg Air Temp 40°F
Above Ambient +129°F
Great soaking conditions September
Access
Open
Road Access Roadside
Nearest Road Salmon River Scenic Byway
Distance to Road 143 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 Sunbeam Hot Springs?
Sunbeam Hot Springs has a water temperature of 169°F (76°C). This is considered a hot spring, well above body temperature.
Where is Sunbeam Hot Springs located?
Sunbeam Hot Springs is located in Custer County, Idaho at 6,160 feet elevation, near Challis. Coordinates: 44.2680°N, 114.7480°W.
How do I get to Sunbeam Hot Springs?
Sunbeam Hot Springs has Roadside road access, with the nearest road being Salmon River Scenic Byway (143 ft from the road).
Is Sunbeam Hot Springs free to visit?
Sunbeam Hot Springs has Open access. It is managed by US Forest Service.
Can I camp near Sunbeam Hot Springs?
Yes, Pole Flat Campground is located nearby (2.9 miles away).
What minerals are in the water at Sunbeam Hot Springs?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 9.0 (alkaline). Total dissolved solids measure 291 mg/L.
Is it safe to soak at Sunbeam Hot Springs?
No, not at the source. The water at Sunbeam Hot Springs reaches 169°F, which can cause severe burns within seconds. Look for cooled side pools or downstream stretches, and test with a hand before anything else.