The slough is one of Southern California's largest remaining salt marshes without a road or railroad trestle running through it.

This important salt marsh is surrounded by San Diego County and Tijuana, Mexico, with a population of 4.3 million people.

Within this international bioregion, the refuge maintains essential habitats for many migrating shorebirds and waterfowl along the Pacific Flyway.

[3] Tijuana Slough provides critical habitat for the federally listed endangered California least tern (Sterna antillarum browni), light-footed rail (Rallus obsoletus levipes) and least Bell's vireo (Vireo bellii pusillus), as well as the salt marsh bird's-beak (Cordylanthus maritimus maritimus), an endangered plant species.

This article incorporates public domain material from websites or documents of the United States Fish and Wildlife Service.