Dutch Frank Hot Spring
Dutch Frank Hot Spring runs at a scalding 149 degrees F along Middle Fork Road in the Boise National Forest, making it one of the hotter accessible springs in the Idaho backcountry. At 4,100 feet elevation in Boise County near Idaho City, the water emerges just 87 feet from the road with a pH of 9.6 and extremely low mineral content.
The spring sits in a forested canyon where ponderosa pine and Douglas fir line the Middle Fork drainage. Steam rises visibly from the source in cooler months, drifting through the canopy and carrying a faint sulfur note. The creek runs nearby, its cold water a sharp contrast to the thermal outflow. This stretch of forest sees heavy snow, averaging over 10 feet annually, and the surrounding hills hold white well into spring while the hot water keeps its channel clear.
The Boise National Forest sits atop the Idaho Batholith, a massive granitic intrusion where deep fractures channel rainwater miles underground before it resurfaces superheated. Dutch Frank's chemistry, dominated by sodium at 57 mg/L with minimal calcium and magnesium, is typical of these deep-circulating batholith systems. The spring's 149-degree temperature suggests a reservoir well below the surface. The area saw placer mining activity in the 1860s gold rush centered on Idaho City.
The Barber Flat Cabin, a 1935 CCC-built rental about 6 miles away, offers reservable lodging with historic character. The spring itself is roadside but extremely hot at 149 degrees F. Do not enter the source pool. This is National Forest land with open public access. Snow exceeds 10 feet annually, so winter visits require preparation. The nearby town of Idaho City has services.
Is Dutch Frank Hot Spring worth visiting?
Best for
- Observing powerful hot springs
- Easy day trips
- Overnight camping trips
Not ideal for
- Casual soaking
The water at Dutch Frank Hot Spring is alkaline (pH 9.6).
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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...