The Tijuana Estuary is the largest coastal wetland in Southern California and it is located on the international border between the U.S. and Mexico. The estuary is primarily a shallow water habitat, though it is often termed an "intermittent estuary," as it is subjected to extreme changes in streamflow at different times of the year. Extended periods of drought leave parts of the estuary dry during some periods, while flooding inundates the same areas during others. For this reason, Tijuana Estuary is considered to be a very unique part of the National Estuarine Research Reserve System.

The Tijuana River Estuary is one of the few salt marshes remaining in Southern California, where over 90% of wetland habitat has been lost to development. The site is an essential breeding, feeding and nesting ground and key stopover point on the Pacific Flyway for over 370 species of migratory and native birds, including six endangered species.

The Reserve offers four miles of walking trails, taking visitors into prime bird watching areas and down to the river mouth where the Tijuana River meets the Pacific Ocean. Visitors may explore the park on their own or join one of the free guided nature and bird walks on weekends. View calendar of events.

Border Field State Park is located in the southwestern corner of the Reserve, on a bluff overlooking the ocean, the estuary, and the bull ring that lies just south of the U.S./Mexico border.  A marker on the bluff, first placed there in 1851 just after the treaty of Guadalupe Hidalgo, delineates the western beginning of the International Border.


State Parks Tagged With: Imperial Beach