Theodore J. Hoover Natural Preserve, which includes Waddell Marsh, is located at the mouth of Waddell Creek, a coastal freshwater marsh that is one of the rarest habitats on the Central Coast of California. This marsh is one of the few relatively undisturbed bodies of fresh water left along the West coast. The land is 23 acres of wetland habitat. It is part of the Rancho del Oso Big Basin Redwoods State Park, located approximately 65 miles south of San Francisco. The elevation in the park ranges from sea level to over 2,000 feet. The area was named after William W. Waddell, who established the last of his four sawmills there in 1868. The sawmill ran down after his death in 1875. All the boilers were left in the area; they are now completely surrounded by second-growth redwoods. Other trees found in the park are Conifers, and Oaks.