Unnamed Thermal Spring
This 86-degree thermal spring sits at 6,800 feet elevation near Mammoth Lakes where water runs 38 degrees above the frigid ambient air, making it one of the warmest springs in the Mono County high country. The proximity to Crowley Lake and accessible location combine to create a compelling thermal destination.
The spring emerges in high desert-alpine transition terrain where Jeffrey pines and whitebark pines give way to alpine scrub at higher elevations. Warm water rises from fractured rock in a landscape sculpted by Pleistocene glaciers, now stripped of year-round snow cover. The terrain rolls gently compared to surrounding peaks.
The spring flows on land managed by the Los Angeles Department of Water and Power, part of the aqueduct system that has shaped Eastern Sierra development for over a century. The thermal water's origin reflects deeper crustal heat sources maintained by active fault zones running through Mono County's volcanically active crust.
This roadside location sits just 83 meters from vehicle access, requiring minimal hiking effort. Tap into summer through early autumn for the most pleasant air temperatures, though the spring's heat advantage diminishes as ambient air warms. Winter visits require careful attention to snow accumulation and cold exposure.
Is this spring worth visiting?
Best for
- Warm-water soaking
- Easy day trips
- Overnight camping trips
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...