Unnamed Thermal Spring
This 73-degree spring in Sonoma County wine country, with recent USGS measurements of 32°C, flows at just 340 feet elevation with water 13 degrees warmer than ambient air.
A 145-meter walk from Keiser Lane leads through oak woodlands and vineyard-dotted slopes toward this modest warm spring. The terrain rolls gently beneath mature oaks and scattered madrone trees. The water emerges clear and steady, creating a small warm pool in shade. Nearby vineyards cover the hillsides, evidence of the region's world-class viticulture.
The 145-meter walk over moderate terrain is accessible to most visitors. Spring through autumn offers the most pleasant visiting conditions, with mild weather and lower water flow. Winter brings increased rainfall and muddy approaches. Sunset hours create golden light across nearby vineyards.
This spring lies within the diverse geology of Sonoma County, where coastal mountain ranges meet inland valleys. The warm water reflects heat from subsurface geology shaped by millions of years of tectonic activity. The region has supported human settlement and agriculture for centuries, from Native Americans through Spanish colonial periods to modern wine production.
The water at This spring contains 641 mg/L total dissolved solids.
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Overview Nestled between Blue Ridge and Cedar Roughs east of Napa Valley, Lake Berryessa provides ample public recreation opportunities. Popular activities on and around the large, yet uncrowded lake include fishing, boating, water skiing, wake boarding, jet skiing, sailing, swimming, kayaking, canoeing, wildlife viewing, hiking, biking and picnicking. The Dufer Point Visitor Center offers year-round interpretive events and exhibits highlighting natural and cultural resources. Lake Berrye...
this spring is road-accessible, so you can bring more gear.
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