Describe the journey up the Rio Grande.

Rio Grande, Spanish Río Grande del Norte, or (in Mexico) Río Bravo, or Río Bravo del Norte, fifth longest river of North America, and the 20th longest in the world, forming the border between the U.S. state of Texas and Mexico. Rising as a clear, snow-fed mountain stream more than 12,000 feet (3,700 metres) above sea level in the Rocky Mountains, the Rio Grande descends across steppes and deserts, watering rich agricultural regions as it flows on its way to the Gulf of Mexico. The total length of the river is about 1,900 miles (3,060 km).

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