Pine Flat Hot Springs

Also known as: Pine Flats Hot Springs
Boise County, Idaho · Near Idaho City
44.0620°N, 115.6850°W · 3,720 ft
138°F 33°F air · Good soaking weather 3,720 ft Open Short Walk US Forest Service Camping nearby (0.2 mi)

Eighteen miles or thereabouts from Idaho City, in Boise County, Pine Flat Hot Springs sits on Boise National Forest ground that anyone can use. The water runs hot, past the range you would sit in without letting it cool first. OpenStreetMap spells it Pine Flats, with the s, and so does the campground a couple hundred yards away.

Location

Banks Lowman Road runs a few hundred feet off, so reaching the spring is a short walk. The land is national forest at a low elevation for the Boise mountains. Climate figures show more than ten feet of snow a year and close to three feet of total precipitation, so the state of the road matters as much as the spring does.

Pine Flats campground is right there, a couple hundred yards from the water. On file, the best time is the dead of winter. At 138 degrees the source is hot enough to burn skin, so find where it has mixed and cooled before you get in, and keep children back from the outlet. The pH reading is from 1979. Forest Service land, open.

History of Pine Flat Hot Springs

The record carries it as Pine Flat, singular. OpenStreetMap and the campground beside it go with Pine Flats.

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 Pine Flat Hot Springs.

Aerial view of the ground around Pine Flat Hot Springs LiDAR bare-earth view of the same ground around Pine Flat 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
830 ft above the spring
Within a quarter mile, to the northwest
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
131 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 82% 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
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
Current Conditions
33°F
SSE 0.0 mph 97% Good soaking weather
Today 78° Low 42° Sunny
Spring is +60° warmer
Wednesday 86° Low 46° Sunny 2% precip
Spring is +52° warmer
Thursday 78° Low 43° Showers And Thunderstorms 76% precip
Spring is +60° warmer
Friday 77° Low 42° Areas Of Fog 24% precip
Spring is +61° warmer
Saturday 81° Low 43° Sunny 6% precip
Spring is +57° warmer
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
Where to Stay

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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 →
Temperature
138°F
Warm Hot Boiling
Water Temp 138°F (59°C)
Avg Air Temp 47°F
Above Ambient +91°F
Great soaking conditions September
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
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?
With care. At 138°F Pine Flat 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.