he Gulf Coast Prairies and Marshes ecoregion is found along the southeast coast of Texas and consists primarily of flat plains with low elevations (less than 150 ft). The Gulf Coast Prairies and Marshes region is a nearly level, slowly drained plain less than 150 feet in elevation, dissected by streams and rivers flowing into the Gulf of Mexico. Erosion and deposition in this ecoregion is the result of ALL BUT ONE of the following event. That is