Marten Hot Springs
Marten Hot Springs sits deep in the backcountry of the Nezperce National Forest, more than 8.4 miles from the nearest road. Also mapped as Martin Hot Springs on OpenStreetMap, this remote thermal feature at 4,540 feet straddles the Idaho-Montana border near the Selway River drainage, requiring serious route-finding skills to reach.
The surrounding forest receives nearly 14.4 feet of snow annually and 41 inches of rain, creating dense conifer stands broken by steep drainages. At this elevation the average annual temperature hovers around 42 degrees, and winter buries the landscape for months. The spring emerges in a wild, unvisited setting where the sounds are limited to water, wind, and the occasional bird. No trails lead directly to the source, and the terrain between the nearest road and the spring is rugged and heavily timbered.
The spring's temperature was historically recorded only as "H" for hot, without a precise measurement, reflecting the difficulty of accessing this site even for government surveyors. It sits within a region shaped by the Idaho Batholith, where granitic intrusions created the fractured rock systems that channel heated groundwater to the surface. The Selway-Bitterroot country surrounding Marten Hot Springs remains one of the least developed areas in the contiguous United States.
This is a genuine wilderness-grade destination. The 8.4-mile distance from the nearest road crosses trackless, steep terrain with no maintained trail. Plan for a multi-day trip with full backcountry gear. Paradise Campground, 17 miles away on the Selway River, serves as the closest staging point and offers 11 sites with vault toilets. Check current conditions with the Nezperce National Forest ranger district before attempting access, especially regarding snow levels and river crossings.
Is Marten Hot Springs worth visiting?
Best for
- Backpacking adventures
- Overnight camping trips
Not ideal for
- Day trips with young children
Paradise Campground is located near the Paradise Boating Site which is one of the most popular launching sites on the Selway River. The campground consists of 11 sites complete with picnic tables, and fire rings. Other facilities include 3 vault toilets, hitching rails, and feed bunks. Campground can accommodate RV's or trailers to 25 feet.