7th Grade Texas History Practice Test 2026 - Free Practice Questions and Study Guide

The longest river associated with Texas is the one that runs along and through the state for a long stretch. The Rio Grande flows from the western U.S. down to the Gulf of Mexico, forming a large portion of the Texas–Mexico border and covering more miles inside Texas than the other rivers listed. The Nueces stays in southern Texas and is shorter, the Red River runs along the northern border with Oklahoma, and the Sabine is in East Texas and also shorter. So, by length, the Rio Grande River is the largest river in Texas.