Barth Hot Springs

Ravalli County, Idaho · Near Hamilton
45.5120°N, 115.0460°W · 2,640 ft
140°F 2,640 ft Open Backcountry US Forest Service Camping nearby (10.7 mi)
Very Hot Source, Use Extreme Caution

At 140°F, the source water at Barth 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.

Aerial view of the ground around Barth Hot Springs LiDAR bare-earth view of the same ground around Barth 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.

Ten miles from any road, Barth Hot Springs sits deep in the Payette National Forest, Idaho, a backcountry hot spring. The record lists the county as Ravalli and Hamilton as the nearest town. Source water runs at the top of the hot range, hot enough to scald. Open to the public on Forest Service land.

Location

Around twenty-six hundred feet. Magruder Road is the jumping-off point, ten miles back, and it is the only road the record names. The climate on file is mild on average, around fifty, yet winter still dumps eleven feet of snow. Horse Heaven Cabin, a Forest Service rental, is the camping the record points to, nearly eleven miles off.

This is a multi-day trip. Ten miles each way from Magruder Road, backcountry class, no road closer. Source water is at the edge of scalding, so test before entering anything. The winter months get the nod as best on record, which does not square with the snow total; use judgment. No fee on file.

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 Barth Hot Springs.

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

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

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

Heat Below
82 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 20% 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
31°
Jan
34°
Feb
41°
Mar
46°
Apr
54°
May
65°
Jun
76°
Jul
75°
Aug
65°
Sep
50°
Oct
36°
Nov
28°
Dec
Annual Precip: 30.9 in Annual Snow: 132.7 in
Best Time to Visit
December Air 28°F · Water 140°F · +112° contrast
January Air 31°F · Water 140°F · +109° contrast
February Air 34°F · Water 140°F · +106° contrast
December offers 48°F more contrast than July
Current Conditions
ESE 0.0 mph
Today 74° Low 49° Mostly Sunny
Spring is +66° warmer
Wednesday 79° Low 53° Sunny 1% precip
Spring is +61° warmer
Thursday 77° Low 53° Partly Sunny then Showers And Thunderstorms Likely 68% precip
Spring is +63° warmer
Friday 73° Low 51° Chance Light Rain then Chance Showers And Thunderstorms 52% precip
Spring is +67° warmer
Saturday 78° Low 52° Sunny 5% precip
Spring is +62° warmer
Nearby Camping
Nearby Camping
Horse Heaven Cabin 10.7 mi away

Overview The Horse Heaven Cabin is a historic cabin that sits between two scenic wilderness areas in central Idaho. It provides access to a variety of trails and recreational opportunities unique to the area.  Recreation Visitors to the area enjoy big and small game hunting. Proper licenses are required to hunt within the Idaho and neighboring Montana. There are a variety of hiking and horseback riding trails in the area. Bicycles and motorized travel are not allowed within wilderness boundar...

Reservable Yes
Reserve on Recreation.gov →
Temperature
140°F
Warm Hot Boiling
Water Temp 140°F (60°C)
Avg Air Temp 50°F
Above Ambient +90°F
Great soaking conditions September
Access
Open
Road Access Backcountry
Nearest Road Magruder Road
Distance to Road 10.2 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Payette National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Barth Hot Springs?
Barth Hot Springs has a water temperature of 140°F (60°C). This is considered a hot spring, well above body temperature.
Where is Barth Hot Springs located?
Barth Hot Springs is located in Ravalli County, Idaho at 2,640 feet elevation, near Hamilton. Coordinates: 45.5120°N, 115.0460°W.
How do I get to Barth Hot Springs?
Barth Hot Springs has Backcountry road access, with the nearest road being Magruder Road (10.2 mi from the road).
Is Barth Hot Springs free to visit?
Barth Hot Springs has Open access. It is managed by US Forest Service.
Can I camp near Barth Hot Springs?
Yes, Horse Heaven Cabin is located nearby (10.7 miles away).
Is it safe to soak at Barth Hot Springs?
With care. At 140°F Barth Hot Springs 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.