Much farther south, this river is joined by its largest tributary, the Conchos River.
This river begins to the east of the fourteen thousand-foot peak Mount Wilson. After flowing eastward past the San Juan and Sangre de Cristo Mountains, this river turns southward through such features as the White Rock Canyon. Much farther south, this river is joined by its largest tributary, the Conchos River. On another side, the most notable tributary is the Pecos River, which joins near the Amistad National Recreation Area; however, a much more famous area is the scenic Big Bend National Park. Near this river's mouth, the most populous cities include Reynosa in Mexico and Brownsville in Texas. FTP, identify this major river of Colorado, New Mexico, and Texas that forms a major part of the U.S. border with Mexico. 
This river begins to the east of the fourteen thousand-foot peak Mount Wilson.
{Rio Grande} (also accept {Rio} Bravo del {Norte})