The Rio Grande forms part of the border between the United States and Mexico. In Mexico, the river is also called the Río Bravo or Río Bravo del Norte.
The river rises in Colorado's San Juan Mountains and flows about 1,896 miles to the Gulf of Mexico. After crossing New Mexico, it becomes the international boundary for much of its course, separating Texas from several Mexican states, including Chihuahua, Coahuila, Nuevo León and Tamaulipas.
Major paired border cities along the river include El Paso and Ciudad Juárez, Laredo and Nuevo Laredo, and Brownsville and Matamoros. The river's shifting channel has also caused boundary disputes, including the Chamizal dispute near El Paso, which was resolved through a 1963 settlement.
A common mix-up is the Colorado River, which also crosses the U.S.-Mexico border, but the Rio Grande is the river most directly associated with the long Texas-Mexico boundary.