Barth Hot Springs

Ravalli County 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.

Barth Hot Springs pours out at 140 degrees Fahrenheit deep in the Payette National Forest, over 10 miles from the nearest road. This is a genuine backcountry destination requiring multi-day commitment to reach. At 2,640 feet elevation in a river canyon, it sits nearly 90 degrees above the annual air temperature, producing vigorous steam and hot pools along the riverbank.

The spring occupies a narrow canyon bottom where the Selway-Bitterroot country meets the Frank Church-River of No Return Wilderness. Steep, forested walls rise thousands of feet on both sides. Ponderosa pine and Douglas fir give way to subalpine species on the ridges above. The river runs cold and fast, providing natural mixing pools where hot spring water blends to soakable temperatures. Winter brings over 11 feet of snow to the surrounding mountains, though the low canyon elevation moderates conditions somewhat.

History of Barth Hot Springs

The Magruder Road, built in the 1930s as a Civilian Conservation Corps project, remains one of the most remote maintained roads in the lower 48 states. Barth Hot Springs lies well south of this road, accessible only by trail through country that has seen minimal human development since Nez Perce bands traveled these corridors. The springs emerge along deep crustal faults in Precambrian metamorphic rock overlain by Idaho Batholith granite.

Plan a multi-day backpacking trip to reach Barth Hot Springs. The 10-plus-mile approach from Magruder Road crosses rugged terrain with significant elevation change. Horse Heaven Cabin, a historic Forest Service rental 17 kilometers away, accepts reservations and could serve as a staging point. Source water at 140 degrees Fahrenheit requires mixing with river water for safe soaking. Pack bear-resistant food storage. No cell service. Best attempted July through September.

Is Barth Hot Springs worth visiting?

Best for

  • Observing powerful hot springs
  • Backpacking adventures
  • Overnight camping trips

Not ideal for

  • Casual soaking
  • Day trips with young children
Barth Hot Springs rewards those willing to make the trek with a more secluded soaking experience.
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
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 →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Sturdy footwear Trail or off-road approach
Camping gear Nearby camping at Horse Heaven Cabin
Trash bag Pack out what you pack in
Water shoes Hot ground near source
References
USGS Quad: SHEEP HILL 7.5 · PP 492: 11.0 · NOAA: 2.0 · AMS Map: ELK CITY
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?
At 140°F, Barth Hot Springs is hot enough to require caution. Enter slowly, limit soaking sessions to 15–20 minutes, and stay hydrated. Always tell someone your plans before visiting remote hot springs.
Is Barth Hot Springs crowded?
Barth Hot Springs requires a hike or off-road travel, which naturally limits crowds. You'll generally find fewer visitors on weekdays and outside peak season.
What should I bring to Barth Hot Springs?
Essentials for Barth Hot Springs: swimsuit, towel, water bottle, sturdy footwear for the approach, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.
Temperature
140°F
Warm Hot Boiling
Water Temp 140°F (60°C)
Avg Air Temp 50°F
Above Ambient +90°F
Great soaking conditions March
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