Yampa River-Colorado River Drainage Divide Origin Determined from Topographic Map Evidence, Southern Routt County, Colorado, USA

Eric Clausen

doi:10.4236/ojg.2021.118017

Abstract

Detailed topographic map evidence and a new Cenozoic geologic and glacial history paradigm are used to determine the previously unexplained Yampa River-Colorado River drainage divide origin. The Yampa River now flows in a north direction away from the Colorado River (between the Park Range to the east and the Flat Tops region to the west) before turning in a west direction to reach the Unita Mountains where it joins the south-oriented Green River, which eventually joins the southwest-oriented Colorado River. Topographic maps show the Yampa-Colorado River drainage divide is asymmetric with steeper slopes leading to the Colorado River, barbed (south-oriented) tributaries leading to north-oriented Yampa River headwaters (especially near the Yampa River turn to the west), and evidence of a large north-to-south oriented diverging and converging channel complex that preceded present-day drainage routes. Map evidence is interpreted to mean massive south-oriented floods flowed through what are now north-oriented Yampa River headwaters valleys and that headward erosion of a deep west-oriented valley beheaded and reversed those south-oriented flood flow channels to create the north-oriented Yampa River headwaters and the Egeria Park area Yampa-Colorado River drainage divide seen today. Large south-oriented floods leading to the Colorado River (while regional uplift was occurring) are inconsistent with accepted Cenozoic geologic and glacial history paradigm predictions, but are predicted by a newly proposed Cenozoic geologic and glacial history paradigm in which a thick continental ice sheet created a deep “hole” by eroding underlying bedrock and also by causing crustal warping that raised the present-day northern Colorado east-west continental divide as immense south-oriented meltwater floods flowed across it.

Highlights

Topographic maps show the Yampa-Colorado River drainage divide is asymmetric with steeper slopes leading to the Colorado River, barbed tributaries leading to north-oriented Yampa River headwaters, and evidence of a large north-to-south oriented diverging and converging channel complex that preceded present-day drainage routes
The Yampa River-Colorado River drainage divide in Egeria Park is located on east-southeast sloping Five Pine Mesa which is drained by eastsoutheast oriented Five Pine Mesa Creek, which makes an abrupt turn to join northwest-oriented Chimney Creek
Detailed topographic maps provide an excellent information source available to researchers wanting to answer drainage history questions, answers obtained often differ from accepted Cenozoic geologic and glacial history paradigm expectations

Summary

Introduction

The accepted Cenozoic geologic and glacial history paradigm (accepted paradigm) does not permit geomorphologists to explain most drainage divide origins. This paper illustrates how a recently proposed and fundamentally different Cenozoic geologic and glacial history paradigm (new paradigm) and detailed topographic maps available at the United States Geological Survey (USGS) National Map website permit the southern Routt County (Colorado) Yampa-Colorado River drainage divide origin to be determined. A Yampa River tributary (known as the Bear River) seen in Figure 1 and Figure 2 flows in a northeast direction before joining northwest-oriented Chimney Creek (which has south- and east-oriented tributaries) to become (north of Figure 2) the north-oriented Yampa River, which after flowing in north, northeast, and north directions, turns in a west direction to join the south-oriented Green River.

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Conclusion