Thermopolis Hot Springs

Hot Springs County, Wyoming · Near Thermopolis
43.6540°N, 108.1940°W · 4,365 ft
133°F 4,365 ft Open Roadside SPR

Thermopolis Hot Springs is the big one in Wyoming, the source in Hot Springs State Park on the edge of Thermopolis, and its county is named Hot Springs for a reason. Water emerges hot, too hot to get into at the source. The park runs a free bath house where the water is cooled to bathing temperature. Roadside, open, state park ground.

Location

In town, essentially, on state park land at the Bighorn River. The road is under a hundred feet away. Low elevation for Wyoming and dry, with mild mean temperatures and light snow. The record lists no campground.

Open year round, with winter listed as best on file. The State Bath House offers free soaking in moderated water, per Wikipedia. Source water is hot enough to burn, so keep to the developed pools. No campground is recorded here. The USGS site on file has no chemistry attached.

History of Thermopolis Hot Springs

Hot Springs State Park is a public recreation area known for springs that flow at a constant hot temperature. The State Bath House in the park moderates that water to a therapeutic 104 degrees and charges nothing to bathe. Legend Rock, a petroglyph site about 25 miles away, is also part of the park.

Then & Now

The Rainbow Terraces of Hot Springs State Park, seen across the Bighorn River. Hot water spilled straight over the travertine in 1914. It runs through pipes and channels today, and algae has painted the terraces orange and yellow.

Thermopolis Hot Springs in 1914 Thermopolis Hot Springs in 2014
1914 2014

Drag to compare.

1914: A. G. Lucier, Library of Congress, public domain. 2014: Paul Hermans, CC BY-SA 4.0.

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 Thermopolis Hot Springs.

Aerial view of the ground around Thermopolis Hot Springs LiDAR bare-earth view of the same ground around Thermopolis 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
Hillside
The spring sits on a steep slope that climbs to the northeast.
Highest ground nearby
315 ft above the spring
Within a quarter mile, to the northeast
Cross-section through the spring

A slice through the ground from north to south, about 0.6 miles end to end.

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

Heat Below
76 milliwatts per square meter of heat flow

That's close to the US average of 65. It's higher than at 11% 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
22°
Jan
25°
Feb
39°
Mar
46°
Apr
56°
May
69°
Jun
78°
Jul
75°
Aug
64°
Sep
47°
Oct
34°
Nov
22°
Dec
Annual Precip: 11.5 in Annual Snow: 27.3 in
Best Time to Visit
January Air 22°F · Water 133°F · +111° contrast
December Air 22°F · Water 133°F · +111° contrast
February Air 25°F · Water 133°F · +108° contrast
January offers 56°F more contrast than July
Current Conditions
Tuesday 78° Low 40° Mostly Sunny
Spring is +55° warmer
Wednesday 78° Low 46° Sunny
Spring is +55° warmer
Thursday 81° Low 47° Partly Sunny 6% precip
Spring is +52° warmer
Friday 81° Low 52° Sunny then Slight Chance Showers And Thunderstorms 15% precip
Spring is +52° warmer
Saturday 75° Low 45° Chance Showers And Thunderstorms 31% precip
Spring is +58° warmer
Where to Stay

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Temperature
133°F
Warm Hot Boiling
Water Temp 133°F (56°C)
Avg Air Temp 48°F
Above Ambient +85°F
Great soaking conditions September
Access
Open
Road Access Roadside
Distance to Road 84 ft
Land
Ownership State
Agency SPR
Designation State Park
Unit Hot Springs State Park
Manager SPR
Protection 2 - Permanent protection, some use allowed
Frequently Asked Questions
What is the water temperature at Thermopolis Hot Springs?
Thermopolis Hot Springs has a water temperature of 133°F (56°C). This is considered a hot spring, well above body temperature.
Where is Thermopolis Hot Springs located?
Thermopolis Hot Springs is located in Hot Springs County, Wyoming at 4,365 feet elevation, near Thermopolis. Coordinates: 43.6540°N, 108.1940°W.
How do I get to Thermopolis Hot Springs?
Thermopolis Hot Springs has Roadside road access (84 ft from the road).
Is Thermopolis Hot Springs free to visit?
Thermopolis Hot Springs has Open access. It is managed by SPR.
Is it safe to soak at Thermopolis Hot Springs?
With care. At 133°F Thermopolis Hot Springs 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, Wikipedia