Gregson Hot Springs

Deer Lodge County, Montana · Near Warm Springs
46.0440°N, 112.8110°W · 5,137 ft
158°F 30°F air · Good soaking weather 5,137 ft Roadside Camping nearby (3.5 mi)
Very Hot Source, Use Extreme Caution

At 158°F, the source water at Gregson Hot Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking. Always test the water temperature before entering.

Gregson Hot Springs, the name Wikipedia also gives as Fairmont Hot Springs, is a geothermal system where the water comes out scalding, well past anything you could sit in. The row puts it in Deer Lodge County, with the town of Warm Springs next door, though Wikipedia files it under Silver Bow County. It sits a few steps off the road. A USGS site is attached, sampled in the late seventies.

Location

Roadside in every sense. The spring sits a few paces off a road, though which road goes unrecorded. This is valley floor by Montana standards. Snow piles up through the winter, close to six feet over a season, and total precipitation is moderate. High Rye Cabin is the closest camping on file, about three and a half miles away.

The water is far too hot to touch at the source. Keep skin out of it. Winter is the listed season, which fits a hot spring, though the snow means checking roads. The 1978 USGS sample ran alkaline with iron present. Whoever owns the ground is not recorded, and no fee or access status is given, so assume nothing about walking up to it.

History of Gregson Hot Springs

Wikipedia treats Gregson and Fairmont Hot Springs as the same system and places it in Silver Bow County. For years the mineral water was believed to ease rheumatism and arthritis, among other complaints. The USGS keeps a numbered monitoring site on it, with chemistry dating to August 1978.

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 Gregson Hot Springs.

Aerial view of the ground around Gregson Hot Springs LiDAR bare-earth view of the same ground around Gregson 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.

Setting
Open ground
Flat, open ground all around.
Highest ground nearby
29 ft above the spring
Within a quarter mile, to the west
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
95 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 40% 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
21°
Jan
21°
Feb
30°
Mar
37°
Apr
47°
May
57°
Jun
66°
Jul
65°
Aug
55°
Sep
41°
Oct
28°
Nov
19°
Dec
Annual Precip: 21.1 in Annual Snow: 70.3 in
Best Time to Visit
December Air 19°F · Water 158°F · +140° contrast
January Air 21°F · Water 158°F · +137° contrast
February Air 21°F · Water 158°F · +137° contrast
December offers 48°F more contrast than July
Current Conditions
30°F
Clear N 0.0 mph 93% Good soaking weather
Today 71° Low 39° Areas Of Frost then Sunny
Spring is +87° warmer
Wednesday 70° Low 42° Sunny
Spring is +88° warmer
Thursday 76° Low 45° Mostly Sunny then Chance Showers And Thunderstorms 51% precip
Spring is +82° warmer
Friday 69° Low 41° Showers And Thunderstorms Likely 67% precip
Spring is +89° warmer
Saturday 72° Low 42° Mostly Sunny then Slight Chance Light Rain 15% precip
Spring is +86° warmer
Water Chemistry Sampled 1978-08-19

The water at Gregson Hot Springs is slightly alkaline (pH 8.5).

pH 8.5 Slightly Alkaline
pH influences mineral absorption through skin
Calcium 4 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 180 mg/L
Supports circulation and skin hydration
Sulfate 190 mg/L
Traditionally used for skin conditions and inflammation
Chloride 16 mg/L
Natural antiseptic with skin health benefits
Iron 20 µg/L
Iron-rich springs may support circulation
Where to Stay

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Nearby Camping
High Rye Cabin 3.5 mi away

Overview High Rye Cabin is a quaint place to stay, ideally situated for exploring the northern Fleecer Mountains. An abundance of recreational activities are available in this scenic area. The cabin was built by the Civilian Conservation Corps around 1919 and is located in the historic mining district of German Gulch. It was used as an administrative site until the 1940s, when it was opened to the public. The cabin can be accessed by vehicle; however, during the fall, alternative resourc...

Reservable Yes
Reserve on Recreation.gov →
Temperature
158°F
Warm Hot Boiling
Water Temp 158°F (70°C)
Avg Air Temp 41°F
Above Ambient +117°F
Great soaking conditions September
Access
Road Access Roadside
Distance to Road 22 ft
Frequently Asked Questions
What is the water temperature at Gregson Hot Springs?
Gregson Hot Springs has a water temperature of 158°F (70°C). This is considered a hot spring, well above body temperature.
Where is Gregson Hot Springs located?
Gregson Hot Springs is located in Deer Lodge County, Montana at 5,137 feet elevation, near Warm Springs. Coordinates: 46.0440°N, 112.8110°W.
How do I get to Gregson Hot Springs?
Gregson Hot Springs has Roadside road access (22 ft from the road).
Can I camp near Gregson Hot Springs?
Yes, High Rye Cabin is located nearby (3.5 miles away).
What minerals are in the water at Gregson Hot Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 8.5 (slightly alkaline).
Is it safe to soak at Gregson Hot Springs?
No, not at the source. The water at Gregson Hot Springs reaches 158°F, which can cause severe burns within seconds. Look for cooled side pools or downstream stretches, and test with a hand before anything else.
Sources: USGS NWIS, Wikipedia