Formerly part of the Camp Elliott Military Reservation, the Elliott Chaparral Reserve comprises a diverse mixture of natural coastal and desert habitats that is becoming more and more rare with rapid suburban growth in the San Diego region. The reserve encompasses a narrow, steep-sided ridge of the Kearny Mesa, bounded north and south by broad, flat-bottomed valleys and associated arroyos. The rolling topography is covered with an unusually wide variety of south coastal chaparral, much of it a nearly pure stand of greenwood, intermixed with elements of coastal sage scrub. Forty-five vascular plant species have been identified on the reserve, several of which have a relatively restricted distribution, such as ashy spikemoss, bushrue, and Xylococcus. The soils, formed on an Eocene conglomerate, are thin, pebbly, and leached, making the chaparral plants, particularly chamise, more stunted and open than in most other Southern California locations. Research and teaching opportunities are expanded beyond reserve boundaries onto large open lands, featuring rare vernal pools on clay hard-pan soils, on the adjacent Marine Corps Air Station Miramar.