Native American communities gathered for centuries around the natural hot springs beneath what’s now Sonoma’s Boyes Hot Springs, considering the geothermal waters sacred healing ground long before European settlement. Physician and Episcopalian minister T.M. Leavenworth acquired the land in the 1840s, and British Royal Navy veteran Captain Henry Boyes bought it in 1883, eventually developing it into a resort that took his name.
A fire destroyed the original hotel in 1923, and when it was rebuilt in 1927, architect Joseph L. Stewart designed it in the Spanish Colonial Revival style, with bell towers, arched entrances, and red-tile roofs meant to echo California’s historic missions, giving the property the name it still carries. A Depression-era receivership and, later, wartime service housing U.S. Navy sailors on rest leave interrupted its run as a resort, but it recovered each time. In 1993, drilling crews struck a new source of thermal mineral water 1,100 feet below the inn, confirming it as the only luxury resort in the western United States built atop natural hot artesian springs.