File:ISS020-E-49348 - View of Idaho.jpg — public domain
Granite Creek Hot Spring delivers 131°F water along Middle Fork Road in the Boise National Forest at 4,205 feet, with a pH of 9.4 that makes the water feel almost oily against the skin. The source sits just 240 feet from the road, offering genuine hot spring water without the hike.
The spring emerges near the roadside where Middle Fork Road traces a narrow valley through ponderosa pine and Douglas fir. The water carries virtually no calcium or magnesium, giving it an unusually soft, slippery texture. Steam rises from the source year-round, thickening in winter when temperatures drop well below freezing and snow accumulates past 10 feet. The forest floor around the spring stays green and mossy from constant thermal moisture.
History of Granite Creek Hot Spring
The water chemistry tells the geological story: sodium-dominant at 52 mg/L with zero detectable magnesium, this water has spent significant time circulating through deep granitic rock of the Idaho Batholith. The high pH of 9.4 and near-absence of calcium at 1.9 mg/L indicate the water rose quickly through relatively unfractured rock, picking up little dissolved mineral along the way.
Access from Middle Fork Road is a short walk of about 240 feet. The source temperature of 131°F is dangerously hot at the point of emergence, so test carefully before entering any pooled area. The historic Barber Flat Cabin, a CCC-built structure from 1935, is reservable about 11 miles away. Bring drinking water and pack out all trash.
Is Granite Creek Hot Spring worth visiting?
Best for
- Hot spring soaking
- Easy day trips
- Overnight camping trips
Granite Creek Hot Spring offers an accessible hot spring experience — great for a day trip.
Annual Precip: 29.9 in
Annual Snow: 121.1 in
December
Air 25°F · Water 131°F · +106° contrast
January
Air 27°F · Water 131°F · +104° contrast
February
Air 29°F · Water 131°F · +102° contrast
December offers 47°F more contrast than July
Recent Temperature
132.8°F
(56.0°C)
Measured May 28, 1981
The water at Granite Creek Hot Spring is alkaline (pH 9.4).
pH influences mineral absorption through skin
May support bone density and joint health
Known for muscle relaxation and stress relief
Supports circulation and skin hydration
Traditionally used for skin conditions and inflammation
Natural antiseptic with skin health benefits
Overview
The Barber Flat Cabin site was established for administrative use by the Forest Service in 1923, and was used prior to that by the Barber Lumber Company. At the time, the Forest Service used a cabin already on-site as a guard station and then built a new one in 1927. The current cabin and outbuildings were built by the Civilian Conservation Corps in 1935, and the cabin today looks much as it did back then.
Guests can drive to Barber Flat Cabin in two-wheel drive passenger cars or tr...
Reserve on Recreation.gov →
Swimsuit & towel
Water bottle
Stay hydrated, especially in hot water
Camping gear
Nearby camping at Barber Flat Cabin (Boise National Forest, Id)
Trash bag
Pack out what you pack in
Water shoes
Hot ground near source
10 miles from Idaho City, ID
USGS Quad: GRAND MTN. 7.5 · PP 492: 120.0 · NOAA: 6.0 · AMS Map: HAILEY
What is the water temperature at Granite Creek Hot Spring?
Granite Creek Hot Spring has a water temperature of 131°F (55°C). This is considered a hot spring, well above body temperature.
Where is Granite Creek Hot Spring located?
Granite Creek Hot Spring is located in Boise County, Idaho at 4,205 feet elevation, near Idaho City. Coordinates: 43.8030°N, 115.4010°W.
How do I get to Granite Creek Hot Spring?
Granite Creek Hot Spring has Roadside road access, with the nearest road being Middle Fork Road (237 ft from the road).
Is Granite Creek Hot Spring free to visit?
Granite Creek Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Granite Creek Hot Spring?
Yes, Barber Flat Cabin (Boise National Forest, Id) is located nearby (6.9 miles away).
What minerals are in the water at Granite Creek Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 9.4 (alkaline).
Is it safe to soak at Granite Creek Hot Spring?
At 131°F, Granite Creek Hot Spring 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 Granite Creek Hot Spring crowded?
Granite Creek Hot Spring is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to Granite Creek Hot Spring?
Essentials for Granite Creek Hot Spring: 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.