Hidden Valley Lake is a census-designated place and gated subdivision in southern Lake County, California, set within the Coyote Valley between the towns of Middletown and Lower Lake. It lies about twenty-two miles north of Calistoga, on the far side of the hills that separate Lake County from the Napa Valley. The 2020 census counted 6,235 residents, making the community one of the more substantial population centers in lightly settled Lake County. As a common-interest development managed by the Hidden Valley Lake Association, it operates more like a large, amenity-rich planned community than a conventional town. The community is built around its namesake lake and an 18-hole golf course designed by William F. Bell, the architect known for Torrey Pines. Around these centerpieces sit a clubhouse, swimming pool, tennis courts, and a network of trails for hiking and biking, all maintained through the homeowners association and secured behind a gated entry. This structure gives Hidden Valley Lake a self-contained, resort-oriented character, with recreation woven into daily life rather than being a destination elsewhere. Residents are drawn by the combination of security, shared amenities, and a rural setting. Schools are provided by the Middletown Unified School District, and day-to-day services are found in nearby Middletown and Lower Lake. The tradeoff is distance: Napa and Santa Rosa are roughly a 45-to-60-minute drive over the hill, making the community best suited to those who work remotely, are retired, or prioritize lake and golf living over a short commute. For such households, Hidden Valley Lake offers an unusually complete, self-managed version of Northern California's lake-country lifestyle.