ROCKY MOUNTAIN A Guide to the Geology of Rocky Mountain National Park, Colorado

WERE WE composing a history of this country we would select certain events as markers of time—the Gold Rush, the War between the States, the Custer Massacre—and would point to the wagon ruts of an old trail, a ruined fort, or a cavalry sabre as relics of these events. Were all written history and tradition lost, we would still know, from the marks of the trail across the plains that a great migration had taken place, that the ruined fort indicated a battle, and that the old sabre, picked up on the Little Bighorn, meant the presence of cavalry.

So it is with the history of the earth, which we call geology. A great volcanic eruption took place long before the coming of man. We do not need tradition to tell us of the event; we see the crater and the hardened lava flow.

Most of us take the world for granted. We do not stop to consider the forces which produced the familiar landscapes nor the series of events which the hills and the rocks record. But for him who observes closely, and carefully pieces together his scattered observations, there gradually unfolds a picture of earth history so vast in its span of time that it staggers imagination. If the information presented in the following pages affords the visitor to Rocky Mountain National Park a brief glimpse of this history, revealing to him the origin of the grand scenery which he admires, it will have accomplished its purpose.