Cow Flats Hot Spring

Idaho County, Idaho · Near Grangeville
45.4310°N, 116.0150°W · 3,440 ft
138°F 45°F air · Good soaking weather 3,440 ft Open Roadside US Forest Service Camping nearby (6.2 mi)
Aerial view of the ground around Cow Flats Hot Spring LiDAR bare-earth view of the same ground around Cow Flats 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.

Cow Flats is a hot roadside spring on the Nezperce National Forest in Idaho County, a long drive from anything; Grangeville, the closest town listed, is nearly thirty-five miles off. The water comes up close to a hundred and forty degrees, which hurts. Access is listed open; the ground is Forest Service. Milner Trail, which the record lists as a road, passes within a hundred feet.

Location

Calling this roadside is accurate. Milner Trail comes within about ninety feet of the water, in country a little under thirty-five hundred feet up where winters stack ten or eleven feet of snow while the other seasons are fairly damp. Spring Bar Campground is listed about six miles away. The file holds nothing on what the spring itself looks like.

The temperature sits right at the line where touching hurts. Test carefully. the record says winter, which for a snowbound forest road is a puzzle. No water chemistry was ever sampled here. Spring Bar is the place to camp nearby.

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 Cow Flats Hot Spring.

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

A slice through the ground from northwest to southeast, about 0.6 miles end to end.

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

Heat Below
77 milliwatts per square meter of heat flow

That's close to the US average of 65. It's higher than at 12% 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
32°
Jan
34°
Feb
40°
Mar
46°
Apr
54°
May
64°
Jun
75°
Jul
75°
Aug
65°
Sep
51°
Oct
38°
Nov
31°
Dec
Annual Precip: 35.4 in Annual Snow: 129.1 in
Best Time to Visit
December Air 31°F · Water 138°F · +107° contrast
January Air 32°F · Water 138°F · +106° contrast
February Air 34°F · Water 138°F · +104° contrast
December offers 44°F more contrast than August
Current Conditions
45°F
NNW 0.0 mph 95% Good soaking weather
Today 73° Low 49° Mostly Sunny 1% precip
Spring is +65° warmer
Wednesday 77° Low 53° Sunny 1% precip
Spring is +61° warmer
Thursday 74° Low 53° Light Rain Likely then Showers And Thunderstorms Likely 68% precip
Spring is +64° warmer
Friday 74° Low 52° Chance Light Rain 42% precip
Spring is +64° warmer
Saturday 78° Low 53° Sunny 4% precip
Spring is +60° warmer
Nearby Camping
Nearby Camping
Spring Bar Campground 6.2 mi away

A popular take-out point for floaters of the Salmon River, the Spring Bar Campground offers a boat launching ramp and 18 tent campsites. A table and fire ring are provided at all but two of the sites. Spring Bar is situated next to a relatively flat part of the Salmon River with the south end nestled in the shade of various fruit bearing trees. The surrounding area also provides for fishing, swimming, berry picking, and exploring. Wheelchair accessible picnic facilities are available at Allis...

Reserve on Recreation.gov →
Temperature
138°F
Warm Hot Boiling
Water Temp 138°F (59°C)
Avg Air Temp 50°F
Above Ambient +88°F
Great soaking conditions September
Access
Open
Road Access Roadside
Nearest Road Milner Trail
Distance to Road 86 ft
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 Cow Flats Hot Spring?
Cow Flats Hot Spring has a water temperature of 138°F (59°C). This is considered a hot spring, well above body temperature.
Where is Cow Flats Hot Spring located?
Cow Flats Hot Spring is located in Idaho County, Idaho at 3,440 feet elevation, near Grangeville. Coordinates: 45.4310°N, 116.0150°W.
How do I get to Cow Flats Hot Spring?
Cow Flats Hot Spring has Roadside road access, with the nearest road being Milner Trail (86 ft from the road).
Is Cow Flats Hot Spring free to visit?
Cow Flats Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Cow Flats Hot Spring?
Yes, Spring Bar Campground is located nearby (6.2 miles away).
Is it safe to soak at Cow Flats Hot Spring?
With care. At 138°F Cow Flats Hot Spring is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.
Sources: USGS NWIS