Of the ten streams, all empty into the Gulf of Mexico. Four of the rivers are tributaries: the Pecos flows into the Rio Grande, the Red into the Mississippi River, and the Sabine and Neches flow into Sabine Lake, which is connected to the Gulf of Mexico by the Sabine Pass. The Canadian is a tributary of a tributary. It flows into the Arkansas River, which is itself a tributary of the Mississippi.

Rio Grande – 1,896 miles, 1,250 miles of which are in Texas — although technically on the border between Texas and Mexico

Red River – 1,360 miles of which 680 are in Texas

Brazos River – 1280 miles of which 840 miles are in Texas, making it the longest section of river in Texas

Pecos River – 926 miles most of which is in New Mexico

Colorado River – 862 miles entirely in Texas of which 600 miles are not dry

Canadian River – 760 miles of which 200 miles are in Texas

Sabine River – 555 miles of which 360 miles are in Texas

Trinity River – 550 miles entirely in Texas

Neches River – 416 miles entirely in Texas

Nueces River – 315 miles entirely in Texas

The Trinity River is the longest river with its entire drainage basin in Texas.

The Colorado is the longest river with both it source and mouth in the state.