Wildlife in the park includes bass, trout, Steller's jay, squirrels, woodpeckers, deer, and on rare occasion, black bear.Created over a million years ago, the layered, porous basalt retains rainwater and snow melt, which forms a large underground reservoir.Descendants were responsible for saving the waterfall and nearby land from development, purchasing the property and presenting it as a gift to the state in the 1920s.The people who go boating are able to enjoy the 9 miles (14 km) long lake and are able to explore numerous nooks and crannies well beyond the boundaries of McArthur–Burney Falls Memorial State Park.These include a rail bridge that was used in the 1986 movie Stand By Me, the Pit River Dam, many independent boat docks, and a villa owned by the PG&E employee association.