# Unnamed thermal spring, California

Unnamed thermal spring in California. 73°F (23°C). Short Walk. Sonoma County.

- Page: https://www.soakingsprings.com/hot-springs/california/unnamed-spring-sonoma-county-1
- Source: Soaking Springs, researched and maintained by Armen Suny
- Updated: 2026-09-14

## Can you soak at this spring?

The water leaves the ground at 73°F, about as warm as a heated pool. It's a short walk from the road. We haven't confirmed whether it has a pool or charges a fee.

## Key facts

| Fact | Value |
|---|---|
| Source water temperature | 73°F (23°C) (USGS record; developed pools are often cooled) |
| Total dissolved solids | 641 mg/L |
| Elevation | 340 ft |
| Access | Short Walk, 477 ft from the nearest road (Keiser Lane) |
| County | Sonoma County |
| Nearest town | Kenwood |
| Coordinates | 38.38900, -122.56700 |
| Best months to soak | December, January, February (largest gap between water and average air temperature) |
| Nearest campground | OAK SHORES DAY USE AREA (CA), 21.5 mi |

## About Unnamed thermal spring

Kenwood, in the Sonoma Valley, has an unnamed spring a couple of miles out that the USGS sampled in 2003 and found tepid. The water came out in the low seventies, about what a shaded swimming pool runs, which puts it in seep territory. Nobody has noted whose land it is or if the public is allowed in, and the only name it carries is the USGS site number.

A short walk off Keiser Lane, under five hundred feet, gets you there on paper. Low country, a few hundred feet above sea level, with wet winters and bone-dry summers. Some 27 inches of rain annually, nearly all of it in the cool months, and no snow worth mentioning. The owner and the access status are empty in the record, so the walk may cross private ground.

The season on the list runs December through February, cold enough air that tepid water passes for warm. Nobody recorded who controls the land, so ask around before you walk in off Keiser Lane. The 2003 sample came back fairly high in dissolved solids; the chemistry block carries the number. Camping is thin here. Oak Shores sits more than twenty miles out and it is day use anyway.

## Water chemistry

Lab sample from 2003-07-15 (Water Quality Portal).

| Measure | Value |
|---|---|
| Total dissolved solids | 640.9 mg/L |

## Nearby

- Nearest city page: [Hot springs near Kenwood](https://www.soakingsprings.com/hot-springs/near/california/kenwood), 1 mi away
- State page: [Hot springs in California](https://www.soakingsprings.com/hot-springs/california)
- [Los Guilicos Warm Springs, CA](https://www.soakingsprings.com/hot-springs/california/los-guilicos-warm-springs): 88°F source, TDS 640 mg/L, Short Walk, near Kenwood, Sonoma County
- [Unnamed thermal spring, CA](https://www.soakingsprings.com/hot-springs/california/unnamed-spring-sonoma-county-2): 70°F source, Roadside, near Eldridge, Sonoma County
- [St Helena White Sulphur Spring, CA](https://www.soakingsprings.com/hot-springs/california/st-helena-white-sulphur-spring): 97°F source, pH 8.7, TDS 750 mg/L, Roadside, near Saint Helena, Napa County
- [White Sulphur Springs (California), CA](https://www.soakingsprings.com/hot-springs/california/white-sulphur-springs-california): pH 8.7, TDS 750 mg/L, Roadside, near Saint Helena, Napa County
- [Calistoga Hot Springs, CA](https://www.soakingsprings.com/hot-springs/california/calistoga-hot-springs): 172°F source, Roadside, near Calistoga, Napa County
- [Mark West Springs, CA](https://www.soakingsprings.com/hot-springs/california/mark-west-springs): 88°F source, Roadside, near Larkfield-Wikiup, Sonoma County

## Questions

**What is the water temperature at ?**
 has a water temperature of 73°F (23°C). This is a warm thermal spring.

**Where is  located?**
 is located in Sonoma County, California at 340 feet elevation, near Kenwood. Coordinates: 38.3890°N, 122.5670°W.

**How do I get to ?**
 has Short Walk road access, with the nearest road being Keiser Lane (477 ft from the road).

**Can I camp near ?**
Yes, Oak Shores Day Use Area (Ca) is located nearby (21.5 miles away).

**What minerals are in the water at ?**
Water chemistry analysis shows the presence of Total Dissolved Solids. Total dissolved solids measure 641 mg/L.

## Sources

- USGS thermal springs records, Water Quality Portal lab analyses, OpenStreetMap, Wikipedia/Wikidata, NOAA climate normals