Rancho Coronado

Rancho Coronado Open Space Preserve (Preserve) consists of 120.5 acres in the City of San Marcos on the northern side of the Merriam Mountains, bounded to the east by Twin Oaks Valley Road, and to the north by the Discovery Hills residential community. The City of San Marcos’ South Lake Reservoir exists to the southeast and Discovery Lake exists to the northwest. San Diego Habitat Conservancy commenced active management of all but a 13.8-acre portion of the Preserve in November 2016. SDHC expects to begin managing the remaining 13.8-acre portion in 2021 once restoration of this area is completed.

History: This open space preserve was set aside as mitigation for construction of the Rancho Coronado residential project. A portion of the Preserve area was used as a rock quarry. Of the total acreage, restoration will provide for the creation of 3.24 acres of southern willow scrub, 2.90 acres of oak woodland, and 2.4 acres of Diegan coastal sage scrub; the rehabilitation of 0.30 acre of southern riparian forest; and the reestablishment of 0.04 acre of streambed. The entire site was burned in the May 2014 Cocos Fire.

Habitat: After restoration is completed, the Preserve will consist of 97.7 acres of Diegan coastal sage scrub, 11.5 acres of southern mixed chaparral, 3.33 acres of southern willow scrub, 2.83 acres of oak woodland, 2.0 acres of eucalyptus woodland, and 1.34 acres of southern riparian woodland and forest.

Management Duties: San Diego Habitat Conservancy conducts 5 monitor visits per year at the Preserve to observe and document substantial changes in the habitat composition and the need for remedial measures. Trash and non-native, invasive plant species are removed as necessary. Protocol surveys for the coastal California gnatcatcher will be conducted every 5 years.

Species of Special Interest: summer holly, wart-stemmed ceanothus, coastal California gnatcatcher, yellow warbler, yellow-breasted chat