North America has a storied history which local geologists are happy to explain. It still bears part of the continent of Africa from the collision that joined it to Pangea and formed the Appalacian mountain range. After separating again stray bits of continental crust collided in the west causing a depression that produced an inland sea running from the Artic Ocean and the Gulf of Mexico and eventually left a treasure trove of dinosaur fossils. An anomalous seduction zone created a parallel pair of mountain ranges; the Sierra Nevada and Rocky mountains. Just for fun add a hot spot the fires a super volcano in Yellowstone.
—David Foss