Tijuana River National Estuarine Research Reserve 301 Caspian Way, Imperial Beach, CA91932 Tijuana River National Estuarine Research Reserve, more than 2,500 acres, was officially designated a national wildlife…More refuge in 1980 and a research reserve in 1982. Here the Tijuana River empties into the ocean. A museum at the end of Caspian Drive details the area's biodiversity and acts as a starting point to miles of trails. The reserves make up 2/3 of San Diego's County's biodiversity in what is the most biodiverse county in the continental United States. Visit the website for more information.