Holtville Hot Spring is located in the Imperial Valley, California, a desert farming valley near the Mexican border. Thermal water surfaces here at around 41°C, in an open-air pool suited to wild bathing.
Insider tip — Holtville Hot Springs in California's Imperial Valley near the Mexican border — geothermal artesian well discharging water at 125°F (52°C), cooled to soakable 104–110°F (40–43°C) in the concrete tub. Located in the Salton Sea geothermal field, one of the USA's most productive. Despite the OSM tag indicating Mexico, this site is on the California (US) side near the town of Holtville. Free or low-cost access. Popular winter escape for snowbirds.