The Geysers in northern California is the world’s largest developed geothermal field, a dry-steam resource spread across about 30 square miles with 18 power plants and more than 350 wells. Native Americans used the area for about 12,000 years for healing, ceremony, and practical tasks before European Americans arrived among Pomo, Wappo, and Lake Miwok communities. Named in 1847 for features that were actually fumaroles, it later became a famous resort and then a major power site. Despite declines in steam production by the late 1990s, wastewater recharge projects helped sustain output. The Geysers remains a vital part of California’s renewable energy system.