The Matagorda Bay estuaries, located between Galveston and Corpus Christi, span approximately 430 square miles—roughly the size of San Antonio—along the central Texas coast. The surrounding mainland is characterized by expansive coastal prairie, scattered oak mottes, meandering coastal streams, river bottoms, freshwater marshes, and tidal wetlands.

Freshwater from Texas Hill Country streams and aquifers flows down the Colorado River, where it meets the salty waters of the Gulf of Mexico near the town of Matagorda. These inflows play a vital role in regulating salinity and delivering nutrients and sediments essential to the productivity, health, and resilience of the bay’s ecosystems.

This dynamic confluence of rivers and gulf waters supports rich biodiversity, including thriving populations of fish and wildlife, migratory waterfowl, and overwintering endangered Whooping Cranes.