The Texas–Gulf water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers. The Texas–Gulf region, which is listed with a 2-digit hydrologic unit code (HUC) of 12, has an approximate size of , and consists of 11 subregions, which are listed with the 4-digit HUCs 1201 through 1211. This region includes The drainage that discharges into the Gulf of Mexico from and including Sabine Pass to the Rio Grande Basin boundary. Includes parts of Louisiana, New Mexico, and Texas. List of water resource subregions See also List of rivers in the United States Water resource region References Lists of drainage basins Drainage basins Watersheds of the United States Regions of the United States Resource Water resource regions