Hot Springs

Also known as: Rock Tub Hot Spring
Mono County County, California · Near Mammoth Lakes
37.6480°N, 118.8060°W · 6,981 ft
129°F 6,981 ft Open Short Walk Bureau of Land Management Camping nearby (5.8 mi)
Hot Springs
File:A girl at Mount Whitney, California, July 2007.jpg — cc by-sa 2.0

Hot Springs known locally as Rock Tub Hot Spring deliver 129°F water from the Long Valley Caldera near Mammoth Lakes at 6,981 feet elevation, offering warm thermal bathing in accessible volcanic terrain on Bureau of Land Management public land.

The spring sits roughly 550 feet from the road on sagebrush and volcanic terrain, requiring a short walk through the landscape that defines the Long Valley environment. Recent USGS data shows complex water chemistry (pH 7.3, TDS-rich with sodium and chloride), indicating deep thermal circulation.

History of Hot Springs

Rock Tub Hot Spring's name reflects its historical use—locals bathed in the cooled outflows. The spring sits atop the Long Valley Caldera, a region of intense crustal heating that powers multiple geothermal features across the Mammoth Lakes area.

Park near Crowley Lake Campground, 9.4 kilometers away, and access on Bureau of Land Management public land. The spring is open year-round with no permit required. Water temperature near the vent reaches 129°F; cooler soaking areas exist downstream. Snow may limit road access December through April.

Is Hot Springs worth visiting?

Best for

  • Hot spring soaking
  • Overnight camping trips
Hot Springs is well suited for hot spring soaking and overnight camping trips.
Monthly Climate
30°
Jan
29°
Feb
34°
Mar
41°
Apr
48°
May
61°
Jun
68°
Jul
67°
Aug
61°
Sep
50°
Oct
39°
Nov
29°
Dec
Annual Precip: 16.2 in Annual Snow: 83.6 in
Best Time to Visit
February Air 29°F · Water 129°F · +100° contrast
December Air 29°F · Water 129°F · +100° contrast
January Air 30°F · Water 129°F · +99° contrast
February offers 39°F more contrast than July
USGS Field Measurements
Recent Temperature 84.2°F (29.0°C) Measured Jul 28, 1973
Discharge 0.01 ft³/s Measured Jul 28, 1973
Water Chemistry Sampled 1973-07-28

The water at Hot Springs is slightly alkaline (pH 7.3). It is notably rich in sodium (supports circulation and skin hydration) and chloride (natural antiseptic with skin health benefits).

pH 7.3 Slightly Alkaline
pH influences mineral absorption through skin
Calcium 21 mg/L
May support bone density and joint health
Magnesium 1 mg/L
Known for muscle relaxation and stress relief
Sodium 310 mg/L
Supports circulation and skin hydration
Sulfate 70 mg/L
Traditionally used for skin conditions and inflammation
Chloride 150 mg/L
Natural antiseptic with skin health benefits
Iron 30 µg/L
Iron-rich springs may support circulation
Nearby Camping
Crowley Lake Campground 5.8 mi away

Overview Crowley Lake Campground offers 47 RV/tent sites, maximum recommended RV length is 30 feet. All sites include a fire pit, picnic table and a lantern holder. No hook-up. Potable water is available. Dump station fee is $10.00, no passes accepted. Closest amenities are 2 miles south in Crowley, or 10 miles north in Mammoth Lakes. Recreation Popular activities include lake and stream fishing, boating, windsurfing, horseback riding, hiking, and wildlife viewing. Facilities Crowley Lake...

Reservable Yes
Reserve on Recreation.gov →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Camping gear Nearby camping at Crowley Lake Campground
Trash bag Pack out what you pack in
Water shoes Hot ground near source
References
USGS Quad: MT. MORRISON 15 · PP 492: 125.0 · Circ 790: 56.0 · NOAA: 14.0 · AMS Map: MARIPOSA
Frequently Asked Questions
What is the water temperature at Hot Springs?
Hot Springs has a water temperature of 129°F (54°C). This is considered a hot spring, well above body temperature.
Where is Hot Springs located?
Hot Springs is located in Mono County, California at 6,981 feet elevation, near Mammoth Lakes. Coordinates: 37.6480°N, 118.8060°W.
How do I get to Hot Springs?
Hot Springs has Short Walk road access (0.1 mi from the road).
Is Hot Springs free to visit?
Hot Springs has Open access. It is managed by Bureau of Land Management.
Can I camp near Hot Springs?
Yes, Crowley Lake Campground is located nearby (5.8 miles away).
What minerals are in the water at Hot Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 7.3 (slightly alkaline).
Is it safe to soak at Hot Springs?
At 129°F, Hot Springs is hot enough to require caution. Enter slowly, limit soaking sessions to 15–20 minutes, and stay hydrated. Always tell someone your plans before visiting remote hot springs.
Is Hot Springs crowded?
Hot Springs sees varying levels of visitors depending on the season and day of the week.
What should I bring to Hot Springs?
Essentials for Hot Springs: swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.
Temperature
129°F
Warm Hot Boiling
Water Temp 129°F (54°C)
Avg Air Temp 47°F
Above Ambient +83°F
Perfect soaking weather March
Access
Open
Road Access Short Walk
Distance to Road 0.1 mi
Bath Type Hot spring
Land
Ownership Federal
Agency Bureau of Land Management
Designation PUB
Unit Bishop Field Office
Manager Bureau of Land Management
Protection 3 - Protected, subject to extractive use