Marten Hot Springs

Also known as: Martin Hot Springs
Ravalli County, Idaho · Near Hamilton
46.0060°N, 115.0210°W · 4,540 ft
Hot 4,540 ft Open Backcountry US Forest Service Camping nearby (16.9 mi)
Aerial view of the ground around Marten Hot Springs LiDAR bare-earth view of the same ground around Marten 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.

Deep inside the Nezperce National Forest, Marten Hot Springs is a backcountry thermal site roughly eight and a half miles from the nearest road and better than thirty miles out of Hamilton. Whoever surveyed it wrote the water down as hot and left no number, so there is no temperature on file and no basis for calling it a soak. Public access is listed as open. OpenStreetMap spells it Martin.

Location

This is wet, heavily snowed country in Ravalli County. Upwards of fourteen feet of snow falls in an average winter and the precipitation is heavy, a different climate entirely from the dry springs of southern Idaho. Elevation is moderate, around forty-five hundred feet. Reaching it is a backcountry trip by any measure. The record has no trail in it, so route-finding falls to you.

no best months is on record. Given the snowfall, the practical window is the snow-free part of the year, and you should confirm conditions with the forest before committing. Paradise Campground, seventeen miles distant, is the closest camping the record knows of. Nobody charges anything, as far as the record goes. Treat the temperature as unknown. Hot could mean anything, and the source might be too hot to enter.

History of Marten Hot Springs

The USGS lists a thermal site for this spring, and OpenStreetMap carries the name as Martin Hot Springs, one letter different from the name used here.

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 Marten Hot Springs.

Setting
Canyon floor
Steep ground climbs away on both sides of the spring.
Highest ground nearby
819 ft above the spring
Within a quarter mile, to the southeast
Cross-section through the spring

A slice through the ground from west to east, about 0.6 miles end to end.

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

Heat Below
73 milliwatts per square meter of heat flow

That's close to the US average of 65. It's higher than at 8% 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
25°
Jan
26°
Feb
33°
Mar
37°
Apr
45°
May
56°
Jun
66°
Jul
66°
Aug
57°
Sep
42°
Oct
29°
Nov
22°
Dec
Annual Precip: 41.3 in Annual Snow: 172.7 in
Current Conditions
SSE 0.0 mph
Today 64° Low 42° Mostly Sunny 1% precip
Wednesday 68° Low 46° Sunny
Thursday 68° Low 47° Mostly Sunny then Chance Showers And Thunderstorms 51% precip
Friday 64° Low 45° Chance Light Rain then Chance Showers And Thunderstorms 53% precip
Saturday 68° Low 47° Sunny 4% precip
Where to Stay

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Nearby Camping
Paradise Campground 16.9 mi away

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.

Reserve on Recreation.gov →
Temperature
Hot
Warm Hot Boiling
Avg Air Temp 42°F
Access
Open
Road Access Backcountry
Distance to Road 8.5 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Nezperce National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Marten Hot Springs?
Marten Hot Springs is classified as hot. An exact temperature measurement has not been recorded.
Where is Marten Hot Springs located?
Marten Hot Springs is located in Ravalli County, Idaho at 4,540 feet elevation, near Hamilton. Coordinates: 46.0060°N, 115.0210°W.
How do I get to Marten Hot Springs?
Marten Hot Springs has Backcountry road access (8.5 mi from the road).
Is Marten Hot Springs free to visit?
Marten Hot Springs has Open access. It is managed by US Forest Service.
Can I camp near Marten Hot Springs?
Yes, Paradise Campground is located nearby (16.9 miles away).