One of San Diego County's most precious natural resources, Elfin Forest Recreational Reserve offers approximately 11 miles of hiking, mountain biking, equestrian trails, as well as picnic areas and scenic mountain viewing points. In addition, the natural beauty of the Reserve includes such native plant communities as oak riparian, oak woodland, coastal sage scrub and chaparral. All wildlife and natural resources at the Reserve are fully protected so that future generations may also enjoy these wonders.

The 784-acre Reserve was developed by OMWD in partnership with the San Diego County Water Authority and the U.S. Department of the Interior - Bureau of Land Management, as an element of the Olivenhain Water Storage Project and the Authority's Emergency Storage Project. The Reserve first opened in 1992. Owned by the Authority and managed by OMWD, the Reserve has been designed to unify the interests of domestic water supply development, natural resources management, and recreational opportunities.