The El Moro Elfin Forest in Los Osos, adjacent to the Morro Bay estuary, is a 90-acre natural area belonging to San Luis Obispo County Parks and California State Parks.  Its plant communities include coastal brackish marsh, riparian woodland fringe, pygmy oak woodland, maritime chaparral, coastal dune scrub, and oak and manzanita complex.  The Elfin Forest supports more than 200 species of plants, as well as 110 kinds of birds, 22 species of mammals and 13 species of reptiles and amphibians.  It is home to rare plants, butterflies, snails and birds.  Chumash middens occur throughout the park.

A 4/5 mile boardwalk loop, constructed in 1999, provides access for young and old, walkers and wheelchair users, and protects the Forest's sensitive habitat.  The Los Osos / Morro Bay Chapter of Small Wilderness Area Preservation (SWAP), after being the prime mover in securing the lands, "adopted" the Forest in 1994. The Chapter continues to remove invasive plants, provide erosion control, and conduct plant revegetation projects through its Conservation Committee and "Weed Warriors."  SWAP also sponsors monthly Third Saturday nature walks and educational walks for local schools.