The Colorado Plateau is a land of colorful, sedimentary strata that have been uplifted and dissected into deep canyons by a few large rivers and their tributaries, with extensive between-canyon landscapes in a mostly arid climate. This truly defines the Plateau—colorful, horizontal strata, that are in many places deeply dissected by numerous canyons and made visible by the lack of significant rainfall and vegetation.
Geology and geologic history go hand in hand then to define the Colorado Plateau and this ancient history in no small part determines its present day character. Its history involves the deposition of numerous rock layers or strata laid out in successive waves of environmental change through immense spans of time. These layers record what happened, when it happened and how it all used to look. Geologists use these rock strata to interpret environments that existed here long ago, landscapes as varied as tropical blue seas, meandering rivers, and shifting sand dunes. This is the constructional part of the Colorado Plateau’s history. It involves the time when a multitude of colorful rock layers were laid down, one on top of the other, yielding to us a sequential view of former landscapes. The bulk of the Plateau’s known history is contained in this part of the story, spanning approximately 450 million years, when more than 15,000 feet of sediment was deposited and preserved, much of it still intact upon the landscape. No less important, however, is the destructional part of the story when the strata were subjected to uplift and erosion. This uplift transpired in a way that preserved a great deal of the original horizontal orientation of the strata
How Old is the Colorado Plateau?
There is no simple answer because while the rocks exposed here may be hundreds of millions or even thousands of millions of years old, the Plateau as a distinct landscape feature is much younger. The age of the Colorado Plateau as a discrete geographic province is estimated to be can be bracketed between 70 and 17 million years.