Unnamed Thermal Spring

Mono County, California · Near Mammoth Lakes
37.4130°N, 119.1390°W · 5,585 ft
95°F 5,585 ft Open Hike US Forest Service Camping nearby (7.3 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.

This unnamed thermal point sits in Sierra National Forest, in Mono County, seventeen miles from Mammoth Lakes. The water is soaking warm, a touch below body heat. It is a hike in, a mile and a half or so, on Forest Service land that the agency lists as open. Warm water at the end of a walk, on open ground, is a decent proposition.

Location

High country around 5,600 feet with very heavy snow, around 175 inches a year, and a wet climate for the range. The hike is a mile and a half, and the record gives no road name. National Forest land. Vermillion is the nearest listed campground, about seven miles away.

Our record lists winter as the best months, but with that much snow expect the road to stay closed for much of it. Hike access. Camp at Vermillion. No fee recorded. The Forest Service lists this as open. Soaking warm water, the kind that feels good after a walk in.

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
710 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
123 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 74% 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
34°
Jan
33°
Feb
37°
Mar
42°
Apr
50°
May
63°
Jun
70°
Jul
69°
Aug
63°
Sep
52°
Oct
40°
Nov
32°
Dec
Annual Precip: 36.3 in Annual Snow: 175.2 in
Best Time to Visit
December Air 32°F · Water 95°F · +63° contrast
February Air 33°F · Water 95°F · +62° contrast
January Air 34°F · Water 95°F · +61° contrast
December offers 38°F more contrast than July
Current Conditions
Today 72° Low 47° Sunny
Spring is +23° warmer
Wednesday 69° Low 46° Sunny
Spring is +26° warmer
Thursday 68° Low 46° Sunny
Spring is +27° warmer
Friday 73° Low 49° Sunny
Spring is +22° warmer
Saturday 75° Low 50° Sunny 1% precip
Spring is +20° warmer
Nearby Camping
Nearby Camping
Vermillion 7.3 mi away

Overview Vermillion Campground is located on the northwest shore of Edison Lake, in a shady stand of Ponderosa pine. Most sites provide lake views. The campground is ideal for tents, as well as small RVs. Visitors can enjoy mountain views of the surrounding John Muir and Ansel Adams Wilderness areas.Recreation Edison Lake has a free public boat launch. Canoeing and kayaking near the shoreline are popular activities. Anglers can fish for rainbow, brown or brook trout. Sandy beaches within the...

Reservable Yes
Reserve on Recreation.gov →
Mile-High Advisory 5,585 ft

this spring sits at 5,585 feet above sea level, way above the mile-high mark. You may not feel the altitude strongly, but hot water still dehydrates you faster at elevation. UV is about 22% stronger than at sea level, so bring sunscreen and drink more water than you normally would.

As an Amazon Associate, we earn from qualifying purchases.

Temperature
95°F
Warm Hot Boiling
Water Temp 95°F (35°C)
Avg Air Temp 49°F
Above Ambient +46°F
Good soaking conditions September
Access
Open
Road Access Hike
Distance to Road 1.5 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Sierra 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 95°F (35°C). This is a warm thermal spring.
Where is located?
is located in Mono County, California at 5,585 feet elevation, near Mammoth Lakes. Coordinates: 37.4130°N, 119.1390°W.
How do I get to ?
has Hike road access (1.5 mi from the road).
Is free to visit?
has Open access. It is managed by US Forest Service.
Can I camp near ?
Yes, Vermillion is located nearby (7.3 miles away).