Unnamed Thermal Spring
In the Mayacamas Mountains, this exceptional 120-degree spring flows at 2,170 feet, exceeding ambient temperatures by 62 degrees in one of California's premier geothermal regions.
A short 100-meter walk from Big Sulphur Creek Road brings you to intensely hot water surrounded by mixed conifer forest. Redwood and Douglas fir create deep shade along the approach. The spring's vigorous flow and steaming waters create a striking contrast to the cool, wet forest surroundings. The intense heat radiates noticeably as you approach.
Lake County's geothermal belt includes numerous hot springs, fumaroles, and commercial power plants that harvest Earth's heat. This spring reflects the region's active geological past and present, where magma still heats groundwater in fractured rock. The area has supported human settlement for thousands of years thanks to its thermal resources.
The 100-meter walk is moderate and well-defined. Extreme water temperatures—exceeding 240 degrees Fahrenheit—demand caution and respect. Autumn and spring provide the most comfortable visiting conditions in these higher elevations. Winter may bring snow and muddy trail conditions.
Is this spring worth visiting?
Best for
- Hot spring soaking
- Overnight camping trips
Overview Warm Springs Recreation Area is a day-use park located at Lake Sonoma, which is just a 45 minute drive north of Santa Rosa and a 2 hour trip from San Francisco. There is no overnight camping available at this facility World famous vineyards and a land rich in history surround the lake, where visitors enjoy boating, fishing and exploring the area's extensive trail network.Recreation The Woodland Ridge Nature Trail begins at the park and winds up the ridge, rewarding hikers with great...