Coso Hot Springs

Kern County, California · Near Inyokern
36.0450°N, 117.7690°W · 4,280 ft
207°F 4,280 ft Closed Short Walk DESG Camping nearby (20.9 mi)
Dangerously Hot, Not Safe for Soaking

Coso Hot Springs reaches 207°F, far above safe soaking levels. Contact with this water will cause severe burns. Look for cooled downstream pools or view from a safe distance only.

Inside Naval Air Weapons Station China Lake, a long way out from Inyokern, Coso Hot Springs is a cluster of vents and pools. It is closed. The water comes out scalding, hot enough to cook skin on contact, and a 1964 sample put the pH down near 1.5, which is extremely acidic. This is a listed historic site on a military base, and you cannot visit it.

Location

Desert at a little over four thousand feet on record, inside the fence of a Navy weapons range. Almost no rain. A little snow some winters. A road passes within a few hundred feet of the springs. That road is on the base, and the base is off limits. Chimney Creek Campground, the closest camping on file, is a long drive off.

There is no season for this one because there is no access. The land designation is military and public access is recorded as closed. The water is far above scalding and acidic on top of that. If the place interests you, the interest is historical. Treat the chemistry numbers as sixty year old readings.

History of Coso Hot Springs

The springs are on the National Register of Historic Places. Wikipedia puts them on record of the Mojave Desert, in Inyo County, and the USGS carries a sampling record for them that goes back to 1964. The whole complex now sits inside Naval Air Weapons Station China Lake.

Terrain

USGS hasn't flown a detailed laser scan here yet, so this view comes from aerial photos and older elevation data.

Aerial view of the ground around Coso Hot Springs

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
86 ft above the spring
Within a quarter mile, to the southwest
Cross-section through the spring

A slice through the ground from southwest to northeast, about 0.6 miles end to end.

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

Heat Below
116 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 68% 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
44°
Jan
47°
Feb
53°
Mar
61°
Apr
68°
May
80°
Jun
85°
Jul
84°
Aug
77°
Sep
64°
Oct
52°
Nov
43°
Dec
Annual Precip: 5.7 in Annual Snow: 7.8 in
Best Time to Visit
December Air 43°F · Water 207°F · +164° contrast
January Air 44°F · Water 207°F · +163° contrast
February Air 47°F · Water 207°F · +160° contrast
December offers 42°F more contrast than July
Water Chemistry Sampled 1964-01-01

The water at Coso Hot Springs is strongly acidic (pH 1.5) with 2500 mg/L total dissolved solids. It is notably rich in magnesium (known for muscle relaxation and stress relief), sulfate (traditionally used for skin conditions and inflammation), and iron (iron-rich springs may support circulation).

pH 1.5 Strongly Acidic
pH influences mineral absorption through skin
Higher mineral concentration for therapeutic soaking
Calcium 18 mg/L
May support bone density and joint health
Magnesium 81 mg/L
Known for muscle relaxation and stress relief
Sodium 14 mg/L
Supports circulation and skin hydration
Sulfate 1,400 mg/L
Traditionally used for skin conditions and inflammation
Chloride 0 mg/L
Natural antiseptic with skin health benefits
Iron 28000 µg/L
Iron-rich springs may support circulation
Where to Stay

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Nearby Camping
Chimney Creek Campground 20.9 mi away

Chimney Creek Campground is located within Chimney Peak Recreation Area and is cherry stemmed out of Owens Peak Wilderness. The campground contains 36 sites and is nestled among beautiful pinyon pines, grey pines, and oaks along Chimney Creek at 5,700 feet in elevation. Each site in the campground has a picnic table and fire ring. Potable water is available during the summer months near the very end of the campground loop at site 36. During the summer, days can be warm and dry. The Pacific C...

Reserve on Recreation.gov →
Temperature
207°F
Warm Hot Boiling
Water Temp 207°F (97°C)
Avg Air Temp 63°F
Above Ambient +144°F
Access
Closed
Road Access Short Walk
Distance to Road 361 ft
Land
Ownership DESG
Agency DESG
Designation MIL
Unit Naval Air Weapons Station China Lake
Manager Department of Defense
Protection 4 - No known protection
Frequently Asked Questions
What is the water temperature at Coso Hot Springs?
Coso Hot Springs has a water temperature of 207°F (97°C). This is considered a hot spring, well above body temperature.
Where is Coso Hot Springs located?
Coso Hot Springs is located in Kern County, California at 4,280 feet elevation, near Inyokern. Coordinates: 36.0450°N, 117.7690°W.
How do I get to Coso Hot Springs?
Coso Hot Springs has Short Walk road access (361 ft from the road).
Is Coso Hot Springs free to visit?
Coso Hot Springs has Closed access. It is managed by DESG.
Can I camp near Coso Hot Springs?
Yes, Chimney Creek Campground is located nearby (20.9 miles away).
What minerals are in the water at Coso Hot Springs?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 1.5 (strongly acidic). Total dissolved solids measure 2,500 mg/L.
Is it safe to soak at Coso Hot Springs?
No, not at the source. The water at Coso Hot Springs reaches 207°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