Brazos Santiago Pass is a natural tidal inlet and the southernmost Gulf of Mexico pass into the Lower Laguna Madre, located between the southern tip of South Padre Island and Brazos Island near the Texas-Mexico border. This pass serves as a critical conduit between the hypersaline, shallow lagoon system and the open Gulf, creating a dynamic fishery driven by tidal movement. The surrounding waters are characterized by extreme shallowness, with the Lower Laguna Madre averaging less than 3 feet deep, and the pass itself featuring a historically shallow and shifting channel. This environment supports a remarkable diversity of inshore and nearshore sportfish, with fishing access available from jetties, boats, and nearby piers. The area's productivity is heavily influenced by the tides moving through the pass and seasonal migrations of pelagic species.