Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
FerBicarbonatesManganèse
Morton's Warm Springs Resort, in Kenwood, Sonoma County, California, draws on iron-rich thermal water around 38°C. The site offers both indoor and outdoor baths, set among the rolling hills of California wine country.
Insider tip — Morton's Warm Springs Resort in the Valley of the Moon is a historic Sonoma County family retreat centered on spring-fed pools maintained at naturally warm temperatures, surrounded by oak woodland in the heart of California wine country. The iron-mineral waters have a distinctive reddish tinge from the iron-rich geology of the Sonoma Mountains, and the pools have been a popular weekend escape for Bay Area families since the early 20th century. The resort's picnic grounds, shaded by grand oaks, make it an ideal combination of thermal bathing and outdoor dining with local wines. Arriving with a packed picnic and a bottle from a nearby Kenwood winery is the quintessential local experience.