Between 251 – 299 million years ago, during the Permian period of geologic time, all the continents on Earth were joined together to form the supercontinent of Pangea.
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El Capitan, a part of one of the world's most well-preserved fossil reef, Guadalupe Mountains National Park / NPS - D. Buehler
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Map of the Capitan Reef showing the exposed and buried sections as they are today, Guadalupe Mountains National Park / NPS file
Eighty million years ago, tectonic pressure caused uplift in the region of what is now West Texas and southern New Mexico. Steep fault blocks and erosion created the Guadalupe Mountains and the cliff known as El Capitan that rises 1,000 feet (305 m) above the desert floor.
To learn more about the geology and geologic formations constituting Guadalupe Mountains National Park, click here.