These are the guys who build our many California Dams & Reservoirs. Since they are managing the lake & structures nearby (maybe along with a utility company), long ago they created the recreation spots, lakeshore campsites, some of which accept reservations. These are usually nice facilties, with picnic areas, bathrooms, paved driveways, boat ramps for easy launching, that cater to families, RVers & fishermen. With feees to go with'em. Most of these lakes are located in the California Central Valley.