In a somewhat remote location on the northern end of the City of Oceanside lies a 73-acre bird sanctuary called Whelan Lake. Bordered by Camp Pendleton and adjacent to the City of Oceanside San Luis Rey Wastewater Treatment Plant, Whelan Lake is a man-made body of water that was used to assist a dairy farm operation owned by the Whelan Family. Ellen Whelan, upon her death in 1985, donated the entire 305-acre property to a Board of Trustees with the understanding that the land was to remain protected and used as a sanctuary for migrating and permanent waterfowl.