Sweetwater Marsh NWR is in central San Diego Bay in San Diego County, California. The refuge protects the last remaining salt marsh in San Diego Bay.

Tijuana Slough Refuge is located in the most southwestern corner of the contiguous United States. It is one of southern California's largest remaining salt marshes without a road or railroad...

Border Field State Park is on the very southwestern corner of the United States and 15 miles south of San Diego. Border Field is located within the Tijuana River National Estuarine Research...