Buena Vista Lagoon is a freshwater lagoon adjacent to the Pacific Ocean in the South Coast region of Southern California within North County, San Diego County. The lagoon covers 223 acres of wetland habitat and serves as a geographic border between Carlsbad and Oceanside. Buena Vista Lagoon is managed by the California Department of Fish and Wildlife. The lagoon is home to the , and is California's first Ecological Reserve. Two non-profit organizations are committed to the preservation and management of the lagoon: the Buena Vista Audubon Society and the Buena Vista Lagoon Foundation