List of Slides for Big Bend NP

• The Chisos Mountains, made of volcanic rock, occupy the center of Big Bend NP.
• Volcanic plugs resemble trees.
• Other parts of the park consist of interbedded layers of sedimentary rock and volcanic ash.
• The Rio Grande forms the southern boundary of the park, and of the United States in this region.
• Where tectonic activity has produced mountains that lie across the path of the river, the Rio Grande has cut spectacular canyons.
• Santa Elena Canyon, the westernmost canyon in the park, was cut through faulted and uplifted Cretaceous limestone.
• The canyon walls reach a height of 1500 feet in places.
• Sandy beaches make camping spots for people floating down the river (float trips by permit only).
• Erosion produces rock falls in the canyons.
• Boquillas Canyon, the easternmost and longest canyon in the park, cuts through the Sierra del Carmen mountain range.
• Wind-blown sand is deposited along the side of Boquillas Canyon.
• Wind carrying sand can abrade and polish bedrock surfaces.
• Archeologists study corn-grinding pits and other traces left by prehistoric inhabitants along the Rio Grande.
• Yucca blooms in the desert.