Laguna Madre is a coastal lagoon in Northeastern Mexico. It extends along the coast of Tamaulipas for over 200 km, from the Río Bravo Delta on the north to the mouth of the Soto la Marina River near La Pesca in the south. Laguna Madre is separated from the Gulf of Mexico on the east by a number of barrier islands, including Barra Los Americanos, Barra J…Laguna Madre is a coastal lagoon in Northeastern Mexico. It extends along the coast of Tamaulipas for over 200 km, from the Río Bravo Delta on the north to the mouth of the Soto la Marina River near La Pesca in the south. Laguna Madre is separated from the Gulf of Mexico on the east by a number of barrier islands, including Barra Los Americanos, Barra Jesús María, and Barra Soto la Marina, and is bounded on the west by the Tamaulipan mainland. It is located in the municipalities of Matamoros, San Fernando, and Soto la Marina.