Unnamed Thermal Spring

Mono County, California · Near Mammoth Lakes
37.8360°N, 119.0160°W · 8,159 ft
97°F 35°F air · Good soaking weather 8,159 ft Open Short Walk US Forest Service Camping nearby (4.2 mi)
Aerial view of the ground around the spring LiDAR bare-earth view of the same ground around the spring
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.

High in Inyo National Forest, Mono County, an unnamed spring about fourteen miles from Mammoth Lakes. Water on record is 97 degrees, a proper soaking temperature, and the Forest Service lists access as open. At over eight thousand feet, this is high country, and the year's average temperature is around forty.

Location

Reaching it takes a short walk, roughly a third of a mile; the road has no name on record. Snowfall on file runs to nearly eleven feet most winters, with total precipitation around twenty-two inches. National Forest land, no designation beyond that, and no campground closer than Oh Ridge. The access class on file is open.

Recommended months on file are all snow months, and at this elevation that means a snowbound approach more often than not. Oh Ridge campground is about four miles off. No fee on file. Open Forest Service land. Ninety-seven degrees is bathwater; most people can stay in a good while. No chemistry sample exists on record.

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 this spring.

Setting
Canyon floor
Steep ground climbs away on both sides of the spring.
Highest ground nearby
274 ft above the spring
Within a quarter mile, to the northeast
Cross-section through the spring

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

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

Heat Below
133 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 83% 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
24°
Jan
23°
Feb
28°
Mar
34°
Apr
42°
May
55°
Jun
63°
Jul
61°
Aug
55°
Sep
44°
Oct
32°
Nov
22°
Dec
Annual Precip: 22.1 in Annual Snow: 130.0 in
Best Time to Visit
December Air 22°F · Water 97°F · +75° contrast
February Air 23°F · Water 97°F · +74° contrast
January Air 24°F · Water 97°F · +73° contrast
December offers 40°F more contrast than July
Current Conditions
35°F
WSW 3.2 mph 53% Good soaking weather
Tuesday 70° Low 44° Sunny
Spring is +27° warmer
Wednesday 66° Low 43° Sunny
Spring is +31° warmer
Thursday 66° Low 42° Sunny
Spring is +31° warmer
Friday 67° Low 42° Sunny
Spring is +30° warmer
Saturday 70° Low 44° Sunny 2% precip
Spring is +27° warmer
Nearby Camping
Nearby Camping
Oh Ridge 4.2 mi away

Overview The outstanding lake and mountain views at Oh Ridge Campground make it a favorite spot for both families and anglers. It sits in the eastern Sierra Nevada Mountains in close proximity to the Ansel Adams Wilderness, Yosemite National Park and Mono Lake. The nearby town of June Lake offers the convenience of shopping and dining, while the surrounding land and lakes provide ample outdoor recreation opportunities.Recreation Oh Ridge campers have no problem staying busy and enjoying the o...

Reservable Yes
Reserve on Recreation.gov →
High Altitude Advisory 8,159 ft

At 8,159 feet, this spring is in high-altitude territory where the air is noticeably thinner. Soaking in hot water accelerates dehydration and can amplify altitude effects like headache and fatigue. UV radiation is roughly 33% stronger here. Wear sunscreen even on overcast days and take breaks from the water to rehydrate.

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Temperature
97°F
Warm Hot Boiling
Water Temp 97°F (36°C)
Avg Air Temp 40°F
Above Ambient +57°F
Good soaking conditions September
Access
Open
Road Access Short Walk
Distance to Road 0.3 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Inyo National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at ?
has a water temperature of 97°F (36°C). This is a warm thermal spring.
Where is located?
is located in Mono County, California at 8,159 feet elevation, near Mammoth Lakes. Coordinates: 37.8360°N, 119.0160°W.
How do I get to ?
has Short Walk road access (0.3 mi from the road).
Is free to visit?
has Open access. It is managed by US Forest Service.
Can I camp near ?
Yes, Oh Ridge is located nearby (4.2 miles away).