The Sabine River () is a long river in the Southern U.S. states of Texas and Louisiana, From the 32nd parallel north and downstream, it serves as part of the boundary between the two states and empties into Sabine Lake, an estuary of the Gulf of Mexico. Over the first half of the 19th century, the river formed part of the Spanish–American, Mexican–American, and Texan–American international boundaries. The upper reaches of the river flow through the prairie country of northeast Texas. Along much of its lower reaches, it flows through pine forests along the Texas–Louisiana border, and eventually the bayou country near the Gulf Coast. The river drains an area of , of which are in Texas and in Louisiana. It flows through an area of abundant rainfall and discharges the largest volume of any river in Texas. The name Sabine (es: Río de Sabinas) comes from the Spanish word for cypress, in reference to the extensive growth of bald cypresses along the lower river. The river flows through an important petroleum-producing region, and the lower river near the Gulf is among the most industrialized areas of the southeastern United States. The river was often described as the dividing line between the Old South and the New Southwest. Description The Sabine rises in northeast Texas by the union of three branches: the Cowleech Fork, Caddo Fork, and South Fork. The Cowleech Fork rises in northwestern Hunt County and flows southeast for . The Caddo Fork, shown as "Caddo Creek" on federal maps, rises in two tributary forks, the East Caddo Fork and the West Caddo Fork, in northwestern Hunt County. The South Fork rises in the southwestern corner of Hunt County and flows east for , joining the Caddo Fork and Cowleech Fork in southeastern Hunt County. The confluence of the forks is now submerged in the Lake Tawakoni reservoir. The combined river flows southeast across northeast Texas and is joined by a fourth branch, Lake Fork Creek, downstream from the reservoir. In northeast Texas, the river flows past Mineola, Gladewater, Big Sandy, and Longview, the largest city on the river, to southwest of Shreveport at the 32nd parallel north, where it establishes the Texas-Louisiana boundary. It flows south, forming the state line for the remainder of its course. It is impounded west of Leesville, Louisiana, to form the Toledo Bend Reservoir, with the Sabine National Forest along its western