Unnamed Thermal Spring

Sonoma County County, California · Near Eldridge
38.3570°N, 122.5090°W · 261 ft
70°F 261 ft Roadside Camping nearby (20.4 mi)
File:Cyzicus californicus 37856904.jpg — cc by 4.0

Near Eldridge in Sonoma County, this 70-degree thermal spring flows at just 261 feet elevation with exceptional roadside access only 2.6 meters from your vehicle.

Standing at your car's edge, you can access this warm spring requiring virtually no walking distance. The surrounding landscape transitions from vineyards to oak woodlands typical of Sonoma's transition zone. The spring emerges clear and steadily in a small basin surrounded by native vegetation. Wine country estates and rural homes dot the nearby slopes.

History of This Spring

Eldridge's thermal waters reflect the same geothermal processes active throughout the San Francisco Bay Area's coastal ranges. The region's geology, shaped by major faults and crustal heating, has supported human occupation for thousands of years. The modern wine industry built upon land that Native peoples valued for its natural resources and moderate climate.

This spring offers supreme convenience with near-total roadside access. It remains accessible year-round, though winter rains may affect road conditions in rare cases. Spring and autumn provide the most comfortable visiting weather. The short nature of the walk makes this suitable for visitors of all abilities and ages.

Is this spring worth visiting?

Best for

  • Easy day trips
  • Overnight camping trips
This spring is well suited for easy day trips and overnight camping trips.
Monthly Climate
49°
Jan
51°
Feb
54°
Mar
58°
Apr
63°
May
69°
Jun
71°
Jul
71°
Aug
70°
Sep
65°
Oct
55°
Nov
49°
Dec
Annual Precip: 25.3 in Annual Snow: 0.1 in
Best Time to Visit
January Air 49°F · Water 70°F · +21° contrast
December Air 49°F · Water 70°F · +21° contrast
February Air 51°F · Water 70°F · +19° contrast
January offers 22°F more contrast than August
Nearby Camping
Oak Shores Day Use Area (Ca) 20.4 mi away

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...

Reservable Yes
Reserve on Recreation.gov →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Camping gear Nearby camping at Oak Shores Day Use Area (Ca)
Trash bag Pack out what you pack in
References
USGS Quad: (GLEN ELLEN 7.5) · PP 492: 78.0 · NOAA: 36.0 · AMS Map: SANTA ROSA
Frequently Asked Questions
What is the water temperature at ?
has a water temperature of 70°F (21°C). This is a warm thermal spring.
Where is located?
is located in Sonoma County, California at 261 feet elevation, near Eldridge. Coordinates: 38.3570°N, 122.5090°W.
How do I get to ?
has Roadside road access (9 ft from the road).
Can I camp near ?
Yes, Oak Shores Day Use Area (Ca) is located nearby (20.4 miles away).
Is it safe to soak at ?
is generally safe for soaking at its recorded temperature. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is crowded?
is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to ?
Essentials for : swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in.
Temperature
70°F
Warm Hot Boiling
Water Temp 70°F (21°C)
Avg Air Temp 60°F
Above Ambient +10°F
Mild soaking conditions March
Access
Road Access Roadside
Distance to Road 9 ft