All of it. It is pretty big however, having a length of 3,141 Kilometers (1,952 miles).
It is called US-Mexico border. If you mean the name of the river that defines much of that border, it is called the Rio Grande river (or Rio Bravo del Norte in Mexico).
200 billion dollars
The Rio Grande river is a border along much of the USA and Mexico.
The Rio Grande forms the border between Mexico and Texas and passes through the Chihuahuan Desert over much of its length.
The Rio Grande (known as Rio Bravo in Mexico)
The Rio Grande River, also known as the Rio Bravo del Norte in Mexico.
Rio Grande (name in the U.S.) - Río Bravo del Norte (name in Mexico)
The Mexican border is fenced up to 2000 miles long.
Pretty much just Canada and Mexico.
Rio Grande River
That's not even a real question. It is a statement.
The Rio Grande River.