Pool Creek Hot Spring

Boise County, Idaho · Near Idaho City
43.7600°N, 115.5600°W · 3,760 ft
108°F 33°F air · Good soaking weather 3,760 ft Open Short Walk US Forest Service Camping nearby (0.5 mi)
Aerial view of the ground around Pool Creek Hot Spring LiDAR bare-earth view of the same ground around Pool Creek Hot Spring
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.

Pool Creek Hot Spring comes out of Boise National Forest in Boise County, fourteen miles from Idaho City. It is hot, a little above what most people sit in, and the 1982 sample found soft water with low dissolved solids and a strongly alkaline pH. Public access is open. Ninemeyer Campground is half a mile away.

Location

Middle Fork Road is three or four hundred feet from the water. The spring sits low for the forest, in a spot that collects a lot of snow, roughly ten feet a winter, and a good deal of rain besides, thirty inches of precipitation in an average year. Forest Service land, designated national forest.

Camping is easy, with Ninemeyer Campground half a mile off. The three winter months are marked best, which means snow on Middle Fork Road is the main obstacle. The water is only a few degrees past soaking heat, about as comfortable as a natural spring gets without cooling. Nothing in the record restricts access. The sample is from 1982.

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 Pool Creek Hot Spring.

Setting
Hillside
The spring sits on a steep slope that climbs to the northwest.
Highest ground nearby
542 ft above the spring
Within a quarter mile, to the northwest
Cross-section through the spring

A slice through the ground from southwest to northeast, about 0.6 miles end to end.

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

Heat Below
135 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 86% 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
27°
Jan
30°
Feb
36°
Mar
42°
Apr
52°
May
62°
Jun
73°
Jul
72°
Aug
62°
Sep
48°
Oct
35°
Nov
26°
Dec
Annual Precip: 30.1 in Annual Snow: 122.0 in
Best Time to Visit
December Air 26°F · Water 108°F · +82° contrast
January Air 27°F · Water 108°F · +81° contrast
February Air 30°F · Water 108°F · +78° contrast
December offers 47°F more contrast than July
Current Conditions
33°F
NW 0.0 mph 98% Good soaking weather
Today 75° Low 48° Sunny
Spring is +33° warmer
Wednesday 82° Low 52° Sunny
Spring is +26° warmer
Thursday 73° Low 48° Showers And Thunderstorms Likely 74% precip
Spring is +35° warmer
Friday 74° Low 47° Mostly Sunny then Slight Chance Rain Showers 21% precip
Spring is +34° warmer
Saturday 77° Low 49° Sunny 5% precip
Spring is +31° warmer
Water Chemistry Sampled 1982-08-19

The water at Pool Creek Hot Spring is alkaline (pH 9.6) with 245 mg/L total dissolved solids.

pH 9.6 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 64 mg/L
Supports circulation and skin hydration
Sulfate 28 mg/L
Traditionally used for skin conditions and inflammation
Chloride 2 mg/L
Natural antiseptic with skin health benefits
Nearby Camping
Nearby Camping
Ninemeyer Campground 0.5 mi away

Overview:Due to a wildfire, there are no amenities at the campground.  Currently there are no developed campfire rings therefore when Stage 1 fire restrictions area in effect, no fires are permitted.A stay at Ninemeyer Campground enables guests to enjoy all the beauty and recreation offered along the (Middle Fork Boise River Road) Forest Service (FS) Road 268. Weather is usually good from mid-May through late September and is easily accessible by car in good weather, although the road is some...

Reserve on Recreation.gov →
Temperature
108°F
Warm Hot Boiling
Water Temp 108°F (42°C)
Avg Air Temp 47°F
Above Ambient +61°F
Good soaking conditions September
Access
Open
Road Access Short Walk
Nearest Road Middle Fork Road
Distance to Road 351 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 Pool Creek Hot Spring?
Pool Creek Hot Spring has a water temperature of 108°F (42°C). This is considered a hot spring, well above body temperature.
Where is Pool Creek Hot Spring located?
Pool Creek Hot Spring is located in Boise County, Idaho at 3,760 feet elevation, near Idaho City. Coordinates: 43.7600°N, 115.5600°W.
How do I get to Pool Creek Hot Spring?
Pool Creek Hot Spring has Short Walk road access, with the nearest road being Middle Fork Road (351 ft from the road).
Is Pool Creek Hot Spring free to visit?
Pool Creek Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Pool Creek Hot Spring?
Yes, Ninemeyer Campground is located nearby (0.5 miles away).
What minerals are in the water at Pool Creek Hot Spring?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 9.6 (alkaline). Total dissolved solids measure 245 mg/L.
Sources: USGS NWIS