Click here . Pleistocene .01-2 Climatic fluctuations including 3 major periods of glaciation. Mesa gravels deposited. Pliocene 2-12 Mountain streams rejuvenated and begin canyon cutting. Oligocene 25-38 Volcanism in the region near today's Florissant Colorado.
Rockies are above sea level.
Front Range is uplifted and intermontane parks form. Sedimentary formations of the Garden of the Gods are tilted up. Cretaceous 70-135 Extinction of dinosaurs. A second major mountain building pulse begins in the Rockies, beginning the Laramide Revolution. Purgatoire, Dakota, Benton, and Niobrara Formations are deposited.