Unnamed Thermal Spring
This 91-degree thermal spring near Mammoth Lakes delivers exceptional warmth, running 42 degrees above the cool ambient air where temperatures average just 48.9 degrees annually. Located just 109 meters from Test Station Road, the high temperature combined with easy access creates a premier thermal soaking destination.
The spring emerges along Test Station Road in open sagebrush-covered terrain with scattered conifers providing intermittent shade. Warm thermal water rises from fractured bedrock creating multiple small pools suitable for extended soaking. The sparse vegetation and open sky afford views across the high desert terrain toward distant peaks.
The spring flows in terrain dominated by basin-and-range faulting that extends eastward from the Sierra Nevada into Nevada, maintaining deep heat sources that fuel thermal activity. The relatively high temperature reflects proximity to active geothermal systems more developed in other Mono County locations.
A short 109-meter walk from Test Station Road makes access convenient for day visits. The spring's high temperature requires caution when entering thermal pools—test depth and temperature carefully. Summer visits coincide with warm ambient air that diminishes the thermal contrast, so spring and autumn provide more dramatic soaking conditions with cooler surrounding temperatures.
Is this spring worth visiting?
Best for
- Warm-water soaking
- Overnight camping trips
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...