Vacaville is a city in Solano County, California, on the western edge of the Sacramento Valley, positioned directly along Interstate 80 between the state capital and the Bay Area. It lies about 35 miles from Sacramento and 55 miles from San Francisco, a location that has defined its growth as a commuter and employment center. With a 2020 population of 102,386, Vacaville is among Solano County's largest cities. It was founded in 1851 and named for Juan Manuel Vaca, whose family's land grant once covered the surrounding valley. For much of the twentieth century, Vacaville was known for its orchards and, above all, the Nut Tree, a celebrated roadside restaurant and attraction along I-80 that became an icon of California car culture. That agricultural and roadside heritage evolved into a modern economic identity built on life sciences: Genentech established a major manufacturing campus in Vacaville, and the city now hosts a cluster of biotechnology, pharmaceutical, food processing, and advanced manufacturing employers, including other large firms along the I-80 and I-505 corridors. The city's housing market is broad, mixing established neighborhoods, newer subdivisions, and rural unincorporated areas such as Elmira. Vacaville Unified School District, with 18 schools and roughly 12,700 students, serves most of the city, with portions near Travis Air Force Base falling under Travis Unified. Recreation centers on Lagoon Valley Park, a 306-acre park with a 100-acre lake, hiking and biking trails, and the historic Peña Adobe. For households seeking a family-friendly city with biotech employment, relatively accessible housing, and a midpoint position between Sacramento and the Bay Area, Vacaville offers a practical, well-rounded base in Northern California's I-80 corridor.