I guess you mean the Rio Grande River. It has a length of 2,018 Km (1,255 mi), flowing into the Gulf of Mexico.
The Mississippi river starts in northern Minnesota, at lake Itasca. Then it flows south and empties into the Gulf of Mexico. (It is debated if the Mississippi runs into the Missouri river or if the Missouri runs into the Mississippi river.)
The River Rio Grande is 1,885 miles long. The Rio Grande also forms part of the Northern border of Mexico.
The Rio Grande is the largest river in Mexico .
The Mississippi River empties into the Gulf of Mexico in Louisiana.
Which river did Mexico claim was the border between Texas and Mexico
The Mississippi River has it's source in Minnesota and runs 2,350 miles before emptying into the Gulf of Mexico.
The Gila is a tributary of the Colorado River and is 650 miles long. It is in the south-western states of New Mexico and Arizona. It has its source in western New Mexico.
Mexico claimed the Nueces River defined the US-Mexico border.
The Sabine River separates the lower half of Texas from Louisiana.
The largest river that empties into the Gulf of Mexico is the Mississippi River.
Niger river
The Tula River is a river in central Mexico. It is in the state of Hidalgo, Mexico.