goparks:

6 Strange Geological Formations Found in National Parks

We all know that America is home to majestic landscapes—rolling plains, rugged mountains, deep canyons—but what about the stranger and less well-known geologic formations populating our country? Speleothems, grabens, and upheaval domes may not be household names, but these unusual landforms provide some of the most striking (and, in some cases, downright bizarre) scenery in our national parks.

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