Big Bend National Park is a national park located in the U.S. state of Texas. For more than 1,000 miles, the Rio Grande/Río Bravo forms the international boundary between Mexico and the United States and Big Bend National Park administers approximately 244 miles along that boundary. The 118 miles of river that form the southern park boundary include the spectacular canyons of Santa Elena, Mariscal and Boquillas. The Rio Grande, meandering through this portion of the Chihuahuan Desert, has cut deep canyons with nearly vertical walls through three uplifts made primarily of limestone
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