Wilmont Ranch

Area: 34 acres

 Location: City of Oceanside, San Diego County, CA

Date Acquired: 2001

Acquisition Type:  CNLM owns the preserve.  We protect and manage imperiled species and habitats on the preserve in perpetuity.

Key Habitats: Desert Riparian, Coastal Sage Scrub and Annual Grassland

Species of Special Interest to CNLM: Coastal California gnatcatcher (Polioptila californica californica), Least Bell’s vireo (Vireo bellii pusillus) and Yellow-breasted chat (Icteria virens)


The Wilmont Ranch Preserve was created in 2001 for the conservation of southern willow scrub and the federally endangered least Bell’s vireo (Vireo bellii pusillus) as part of the mitigation for the Wilmont Ranch housing development. The majority of this 34-acre Preserve forms a tributary of Pilgrim Creek, which is adjacent to Marine Corps Base Camp Pendleton. The site will eventually be bordered by houses on either side, but forms a corridor to Pilgrim Creek located to the west.  The Preserve is in a highly urbanized area, surrounded by homes and roads.  The Center for Natural Lands Management (CNLM) owns the property and provides full management.

Conservation Significance

The Preserve has three vegetation communities: southern willow scrub, Diegan coastal sage scrub, and non-native grasslands. The Preserve supports several sensitive species, including five to sevens pairs of least Bell’s vireo (Vireo bellii pusillus) and several yellow-breasted chat (Icteria virens). The small patch of Diegan coastal sage scrub habitat type could also support the federally threatened coastal California gnatcatcher (Polioptila californica californica). Other notable species that have been observed include mule deer (Odocoileus hemionus) and bobcat (Lynx rufous).

Our Work

CNLM is responsible for management of the Wilmont Ranch Preserve. Our goal for this Preserve is to protect the three habitat types from nonnative plant invasion, and to protect the least Bell’s vireo population from potential nest-parasitism from brown-headed cowbirds (Molothrus ater). To achieve these goals we practice removal of nonnative plants, including the giant reed (Arundo donax), tamarisk (Tamarix spp.), fennel (Foeniculum vulgare), castor bean (Ricinus communis), and various non-native grasses. There is very little representation of these species in the riparian area. To protect the least Bell’s vireo population from potential nest-parasitism, we monitor the nests of the species, remove cowbird eggs and checks, and periodically install cowbird traps as needed. This practice has resulted in increased vireo nest success and productivity.

Public Access

Due to the vulnerability of the species and habitats that exist on this preserve, it is not open to the public.


For information about Wilmont Ranch or Center for Natural Lands Management, please contact Preserve Manager, Steve Rink, at 760.731.7790 extension 212 or email srink@cnlm.org.