The Rio Grande, also known as the Río Bravo in Mexico or Tó Ba'áadi in Navajo, is one of the principal rivers in the Southwestern United States and northern Mexico. It originates in south-central Colorado and flows southward to its terminus at the Gulf of Mexico.
Measuring 1,896 miles (3,051 km) in length, it is the fourth longest river in both the United States and North America by main stem. The Rio Grande drainage basin covers an area of 182,200 square miles (472,000 km2), though the total drainage-basin area increases to 336,000 square miles (870,000 km2) when including adjacent and internal endorheic basins.