Middletown is a census-designated place in the southern reaches of Lake County, California, sitting on State Route 29 in the mountain country between the Napa Valley and Clear Lake. The community takes its name from its position roughly halfway between Lower Lake and Calistoga, the Napa County spa town to the south. With a population of 1,114 at the 2020 census, Middletown functions as the commercial and civic hub for a sparsely settled corner of the county that also includes the communities of Cobb and Hidden Valley Lake. The area's defining feature is its geology. Middletown lies about ten miles east of The Geysers, the world's largest complex of geothermal power plants, where underground steam fields have long been tapped for electricity. The geothermal industry brought an influx of workers in the 1970s and early 1980s and remains part of the region's economic identity. The surrounding hills also hold natural hot springs, and Harbin Hot Springs has drawn visitors for generations. Middletown has shown resilience through wildfire. The 2015 Valley Fire swept through the community and neighboring areas, destroying a large share of homes and businesses; in the years since, Middletown has rebuilt its downtown and housing stock. The recovery reshaped parts of the community with newer construction alongside surviving older homes. Schools are provided by Middletown Unified School District, which serves Middletown, Cobb, and Hidden Valley Lake through elementary, middle, and high school campuses including Middletown High School. Recreation centers on the outdoors: Clear Lake to the north, Mount St. Helena rising to the south, and the wineries and spas of Calistoga just over the county line. For residents, Middletown offers a rural, close-knit setting with a manageable commute over Mount St. Helena toward the Napa Valley and the broader Bay Area. Many residents are retirees or commuters who value the area's space, dark skies, and lower density while staying within reach of Napa and Sonoma county employment centers.