Hot Spring, Fumaroles

Also known as: Sulphur Springs
Siskiyou County, California · Near Mount Shasta
41.4070°N, 122.1970°W · 14,000 ft
183°F 43°F air · Good soaking weather 14,000 ft Open Hike US Forest Service Camping nearby (5.2 mi)
Fumarole: Not a Soaking Spring

Hot Spring, Fumaroles is a fumarole, not a traditional hot spring. These geothermal features can be extremely dangerous. Boiling water, toxic gases, and unstable ground are common hazards. Do not attempt to soak.

This is a field of fumaroles and a hot spring listed at fourteen thousand feet in Siskiyou County, above the town of Mount Shasta, which is eight miles or so away. The water is scalding. OpenStreetMap calls the spot Sulphur Springs. It sits on Shasta National Forest land and is marked open. Nothing here is a soak.

Location

Getting there means a hike of about three miles, and the road you start from goes unnamed in the record. Altitude alone makes it hard work. Average temperature sits below freezing year round. Snowfall is enormous. Red Fir Flat group campground is the closest listed, about five miles away, on National Forest ground.

Steam and water at these temperatures will burn. Stay off the vents. The month ranking favors winter, which at this elevation and snowfall reads like a data quirk; weigh it against the climate figures before planning anything. No fee is recorded for the Forest Service land. Thin air and cold are part of any trip here.

History of Hot Spring, Fumaroles

OpenStreetMap names the site Sulphur Springs. The USGS holds a site record for it.

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 Hot Spring, Fumaroles.

Aerial view of the ground around Hot Spring, Fumaroles LiDAR bare-earth view of the same ground around Hot Spring, Fumaroles
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
304 ft above the spring
Within a quarter mile, to the northeast
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
93 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 36% 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
Jan
Feb
Mar
10°
Apr
18°
May
29°
Jun
38°
Jul
38°
Aug
31°
Sep
20°
Oct
Nov
Dec
Annual Precip: 48.7 in Annual Snow: 208.4 in
Best Time to Visit
December Air 2°F · Water 183°F · +181° contrast
January Air 3°F · Water 183°F · +180° contrast
February Air 3°F · Water 183°F · +180° contrast
December offers 36°F more contrast than August
Current Conditions
43°F
Clear N 0.0 mph 70% Good soaking weather
Tuesday 39° Low 26° Sunny 4% precip
Spring is +144° warmer
Wednesday 33° Low 25° Chance Light Snow then Scattered Snow Showers 50% precip
Spring is +150° warmer
Thursday 34° Low 25° Sunny 9% precip
Spring is +149° warmer
Friday 40° Low 27° Sunny
Spring is +143° warmer
Saturday 42° Low 31° Sunny
Spring is +141° warmer
Where to Stay

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Nearby Camping
Red Fir Flat Group Campground 5.2 mi away

Overview Red Fir Flat Group Campground is located on the southern slope of Mt. Shasta at 6,400 feet in elevation. Snowpack in this location may extend into late June on heavy snow years, and usually sees late season snowfall in early November, possibly October. It is a popular site for meditation/retreat groups. Maximum stay limit is 7 days per group and or indvidual(s) Recreation Most visitors enjoy the peace and solitude of the forest setting. Several hiking trails are located nearby, incl...

Reservable Yes
Reserve on Recreation.gov →
Very High Altitude Advisory 14,000 ft

Hot Spring, Fumaroles sits at 14,000 feet, well above 10,000 ft, where the air holds roughly 30% less oxygen than at sea level. Altitude sickness (headache, nausea, dizziness) is a real risk, especially when combined with the dehydrating effects of hot water. UV exposure is approximately 56% stronger than at sea level. Acclimate for at least 24 hours before soaking, drink extra water, and descend if symptoms worsen.

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Temperature
183°F
Warm Hot Boiling
Water Temp 183°F (84°C)
Avg Air Temp 17°F
Above Ambient +166°F
Access
Open
Road Access Hike
Distance to Road 3.1 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Shasta National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Hot Spring, Fumaroles?
Hot Spring, Fumaroles has a water temperature of 183°F (84°C). This is considered a hot spring, well above body temperature.
Where is Hot Spring, Fumaroles located?
Hot Spring, Fumaroles is located in Siskiyou County, California at 14,000 feet elevation, near Mount Shasta. Coordinates: 41.4070°N, 122.1970°W.
How do I get to Hot Spring, Fumaroles?
Hot Spring, Fumaroles has Hike road access (3.1 mi from the road).
Is Hot Spring, Fumaroles free to visit?
Hot Spring, Fumaroles has Open access. It is managed by US Forest Service.
Can I camp near Hot Spring, Fumaroles?
Yes, Red Fir Flat Group Campground is located nearby (5.2 miles away).
Is it safe to soak at Hot Spring, Fumaroles?
No, not at the source. The water at Hot Spring, Fumaroles reaches 183°F, which can cause severe burns within seconds. Look for cooled side pools or downstream stretches, and test with a hand before anything else.