Geology of Big Bend National Park

cerro castellan
Colorful volcanic formations near Castolon.

The physiographic order of the Big Bend is somewhat like the order of a great city built of stone and brick—wrecked by an earthquake. Perhaps order once prevailed there, but some mighty force wrecked the place, shook it down, turned it over, blew it up, and set it afire. Evidences that all this happened exist on every hand, making the land the finest example of earth-wreckage in Texas. ~ Walter Prescott Webb, 1937


From 500-million year old rocks at Persimmon Gap to modern-day windblown sand dunes at Boquillas Canyon, Big Bend preserves tremendous geological diversity, including marine sedimentary rocks, continental sedimentary rocks, volcanic rocks, and evidence of the three great North American mountain-building episodes. On any visit to Big Bend, you can easily observe evidence of sedimentation, tectonics, erosion, volcanism, and fossilization.


Last updated: August 12, 2020

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PO Box 129
Big Bend National Park, TX 79834-0129



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