Pine Flat Hot Springs

Also known as: Pine Flats Hot Springs
Boise County County, Idaho · Near Idaho City
44.0620°N, 115.6850°W · 3,720 ft
138°F 3,720 ft Open Short Walk US Forest Service Camping nearby (0.2 mi)

Pine Flat Hot Springs erupts at 138 degrees Fahrenheit on Forest Service land in Boise National Forest, just 110 meters from Banks Lowman Road. USGS readings of 59.5 degrees Celsius confirm the powerful thermal output. The water registers 91 degrees above the local ambient average, one of the largest temperature differentials in the region.

The spring sits at 3,760 feet elevation along the South Fork Payette River corridor, where steep canyon walls of weathered granite rise on both sides. Whitewater rafters and kayakers pass regularly during summer months. Ponderosa pine and Douglas fir shade portions of the riverbank, and the air carries the sulfur-mineral scent typical of high-temperature alkaline springs. Pine Flats Campground lies just 300 meters away, making this an easy walk from camp. The river's cold water provides natural mixing opportunities.

History of Pine Flat Hot Springs

At 138 degrees Fahrenheit, Pine Flat ranks among Idaho's hotter accessible springs. The pH of 9.2, elevated sodium at 75 mg/L, and negligible calcium indicate deep circulation through the Idaho Batholith's granitic core. The Banks-Lowman corridor follows a major fault zone that channels geothermal fluids to the surface at multiple points. Gold miners worked this stretch of the Boise River basin through the 1860s, and the road itself was built partly to service mining claims.

Source temperature of 138 degrees Fahrenheit is dangerously hot and requires substantial cooling or mixing with river water before any contact. Pine Flats Campground accepts reservations and sits within walking distance. The Banks-Lowman Highway provides year-round paved access. Idaho City lies a short drive east for supplies. Check current fire restrictions, as the area has experienced recent wildfire activity.

Is Pine Flat Hot Springs worth visiting?

Best for

  • Hot spring soaking
  • Overnight camping trips
Pine Flat Hot Springs is well suited for hot spring soaking and overnight camping trips.
Monthly Climate
28°
Jan
31°
Feb
37°
Mar
42°
Apr
51°
May
62°
Jun
73°
Jul
72°
Aug
62°
Sep
47°
Oct
35°
Nov
26°
Dec
Annual Precip: 32.8 in Annual Snow: 126.2 in
Best Time to Visit
December Air 26°F · Water 138°F · +112° contrast
January Air 28°F · Water 138°F · +110° contrast
February Air 31°F · Water 138°F · +107° contrast
December offers 47°F more contrast than July
USGS Field Measurements
Recent Temperature 139.1°F (59.5°C) Measured Feb 27, 1979
Water Chemistry Sampled 1979-02-27

The water at Pine Flat Hot Springs is alkaline (pH 9.2).

pH 9.2 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Sodium 75 mg/L
Supports circulation and skin hydration
Sulfate 38 mg/L
Traditionally used for skin conditions and inflammation
Chloride 7 mg/L
Natural antiseptic with skin health benefits
Nearby Camping
Pine Flats (Id) 0.2 mi away

Overview Pine Flats Campground is located a few miles west of Lowman, Idaho, along the Banks-Lowman Highway at an elevation of 3,700 feet. Visitors enjoy rafting, kayaking and fishing on the South Fork Payette River, and soaking in the hot springs at the river's edge.Recreation The South Fork Payette River flows next to the site, down a small hill, and offers trout fishing, rafting and kayaking. The Danskin River Access area is 5 miles west of the campground. A 1/4-mile nature trail begins i...

Reservable Yes
Reserve on Recreation.gov →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Camping gear Nearby camping at Pine Flats (Id)
Trash bag Pack out what you pack in
Water shoes Hot ground near source
References
USGS Quad: PINE FLAT 7.5 · PP 492: 77.0 · NOAA: 38.0 · AMS Map: CHALLIS
Frequently Asked Questions
What is the water temperature at Pine Flat Hot Springs?
Pine Flat Hot Springs has a water temperature of 138°F (59°C). This is considered a hot spring, well above body temperature.
Where is Pine Flat Hot Springs located?
Pine Flat Hot Springs is located in Boise County, Idaho at 3,720 feet elevation, near Idaho City. Coordinates: 44.0620°N, 115.6850°W.
How do I get to Pine Flat Hot Springs?
Pine Flat Hot Springs has Short Walk road access, with the nearest road being Banks Lowman Road (362 ft from the road).
Is Pine Flat Hot Springs free to visit?
Pine Flat Hot Springs has Open access. It is managed by US Forest Service.
Can I camp near Pine Flat Hot Springs?
Yes, Pine Flats (Id) is located nearby (0.2 miles away).
What minerals are in the water at Pine Flat Hot Springs?
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.2 (alkaline).
Is it safe to soak at Pine Flat Hot Springs?
At 138°F, Pine Flat 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 Pine Flat Hot Springs crowded?
Pine Flat Hot Springs sees varying levels of visitors depending on the season and day of the week.
What should I bring to Pine Flat Hot Springs?
Essentials for Pine Flat Hot Springs: swimsuit, towel, water bottle, 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
138°F
Warm Hot Boiling
Water Temp 138°F (59°C)
Avg Air Temp 47°F
Above Ambient +91°F
Perfect soaking weather March
Access
Open
Road Access Short Walk
Nearest Road Banks Lowman Road
Distance to Road 362 ft
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Boise National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use