It is 1,563 miles or 2,515 kilometers if you prefer.
535.82 kilometres
Zero miles. The Rio Grande forms one of the borders of Texas (and the Texas stretch of the Rio is also the U.S.-Mexico border), so the north bank of the Rio Grande is part of the soil of Texas....
1,205.59 miles (1,940.21 kilometres)
1,820.75 miles (2,930.21 kilometres)