HIGHLAND BAYOU. Highland Bayou rises south of La Marque in central Galveston County (at 29°22' N, 95°03' W) and runs southeast for more than twelve miles before passing into Jones Bay and West Bay (at 29°19' N, 94°56' W). The bayou, which is leveed in its upper reaches, traverses flat to rolling prairie that is surfaced variously by clay and sandy loams and dark, commonly calcareous clays. Local vegetation includes water-tolerant hardwoods and grasses and some mesquite and cacti. At the bayou's mouth, rushes and grasses grow in a brackish saltwater marsh.