The La Plata Mountains as seen from above the author’s home.


Durango Bill's
Paleogeography (Historical Geology) Research



Cenozoic Rivers (of the ancestral Colorado River)
(Paleocene, Eocene, Oligocene, Miocene)
   The maps below show the evolution of river systems starting with the Late Cretaceous/Paleocene through the late Miocene (just before the Grand Canyon event). River positions were drawn free hand with a mouse and are thus subject to some drawing error as well as geologic uncertainties. However, the overall pattern is a reasonably accurate depiction of the Evolution of the Colorado River.

   The maps were generated with Delorme's TopoUSA program. The usual credit notice was chopped off when pictures were edited to fit this page.


Return to the Evolution of the Colorado River page.




Map sjows the general river drainage during the Paleocene.Overview of river drainage during the Eocene.
















       Late Cretaceous to Paleocene                         Eocene
     (About 60 - 70 million years ago)         (About 45 - 50 million years ago.)



General river flow during the Oligocene.
















                                     Oligocene
                            (About 30 million years ago)



Overview of river systems in the Late Miocene.Overview of river systems in the early Miocene

















               Early Miocene                              Late Miocene
       (About 20 million years ago)                (About 6 million years ago)

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(Goodbye Microsoft)