In the several million years that followed there was a major period of mountain building that caused the climate to become both colder and drier as the complex of mountains in the west, the Rockies, the Sierra Nevada, and the Cascades, cut off the supply of water to the center of the continent.
(the Rockies, the Sierra Nevada, and the Cascades; cut off; the supply of water to the center of the continent) (a major period of mountain building; caused; the climate to become both colder and drier as the complex of mountains in the west) Context(a major period of mountain building caused,List([53, 100))):(the climate; to become; both colder and drier as the complex of mountains in the west)
a major period of mountain building caused,List([53, 100))
the Rockies, the Sierra Nevada, and the Cascades a major period of mountain building the climate
cut off caused to become
the supply of water to the center of the continent
the climate to become both colder and drier as the complex of mountains in the west
both colder and drier as the complex of mountains in the west