Abstract:

The Republican River-Beaver Creek drainage divide area in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas was eroded by immense south and/or southeast oriented floods. Flood waters were probably derived from a rapidly melting North American ice sheet and initially flowed across a topographic surface at least as high as the highest Republican River-Beaver Creek drainage divide area elevations today. Missouri River tributary valleys eroded headward into this high level topographic surface in an identifiable sequence (from south to north) to capture the south-oriented flood water and to divert flood flow to what was then the newly eroded Missouri River valley. Headward erosion of the east-northeast oriented Beaver Creek valley, from what was then the actively eroding Republican River valley head, captured the south-oriented flood flow first. Headward erosion of the Republican River valley and its tributary Driftwood Creek valley next captured the south-oriented flood flow and beheaded flood flow channels to the newly eroded Beaver Creek valley. Flood waters on north ends of reversed flood flow channels reversed flow direction to erode north-oriented tributary valleys and to create the Driftwood Creek-Beaver Creek and Republican River-Beaver Creek drainage divide. Continued Republican River valley headward erosion beheaded south-oriented flood flow to the newly eroded Driftwood Creek valley and created the Republican River-Driftwood Creek drainage divide. Evidence supporting this flood origin interpretation includes present day valley positions and orientations and shallow through valleys crossing the major east-northeast oriented drainage divides.

Preface:

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore Republican River-Beaver Creek drainage divide area landform origins in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas, USA. Map interpretation methods can be used to unravel many geomorphic events leading up to formation of present-day drainage routes and development of other landform features. While each detailed topographic map feature provides detailed evidence to be explained, the solution must be consistent with explanations for adjacent area map evidence as well as solutions to big picture map evidence puzzles. I invite readers to improve upon my solutions and/or to propose alternate solutions that better explain evidence and are also consistent with adjacent map area and big picture evidence. Readers may do so either by making comments here or by writing and publishing their own essays and then by leaving a link to those essays in a comment here.

• This essay is also exploring a new geomorphology paradigm in which erosional landforms are interpreted as evidence left by immense glacial melt water floods. Implied in that interpretation is the immense floods were derived from a thick North American ice sheet that created a deep “hole” in the North American continent and also melted fast. The previously unexplored paradigm being tested in this and other Missouri River drainage basin landform origins research project essays is a thick North American ice sheet, comparable in thickness to the Antarctic ice sheet, occupied the North American region usually recognized to have been glaciated, and through its weight and erosive actions created a deep North American “hole”. The southwestern rim of that deep “hole” is today preserved in the high Rocky Mountains. The ice sheet through its weight and deep erosion (and perhaps deposition along major south-oriented melt water flow routes) caused significant crustal warping and tectonic change, through its action of melting fast produced immense floods that flowed across the continent, and through its action of melting fast systematically opened up space in the ice sheet created “hole” so headward erosion of newly developed north-oriented drainage systems captured immense south-oriented melt water floods and diverted the floods north into space the ice sheet had once occupied.

• If this previously unexplored paradigm is correct the geographic region explored by this essay should contain evidence of immense floods that were captured by headward erosion of new valley systems so as to cause the floods to flow in a different direction. Ability of this previously unexplored paradigm to explain Republican River-Beaver Creek drainage divide area landform origins in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Republican River-Beaver Creek drainage divide area location map

Figure 1: Republican River-Beaver Creek drainage divide area location map (select and click on maps to enlarge).  National Geographic Society map digitally presented using National Geographic Society TOPO software.

Figure 1 provides a Republican River-Beaver Creek drainage divide area in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas location map and shows areas of southwest Nebraska, northwest Kansas, and eastern Colorado. Colorado is located along the figure 1 west edge. Nebraska and Kansas are east of Colorado with Nebraska being north of Kansas. The southeast and east oriented Platte River is located in the figure 1 northeast quadrant and flows from near Wizard Island to near Cozad, Lexington, Overton, and Elm Creek, Nebraska. East of the figure 1 map area the Platte River flows in a northeast and then in a generally east and southeast direction to join the south-southeast oriented Missouri River. The Republican River flows in an east-northeast direction from Haigler near the Nebraska southwest corner and then to Benkelman, Stratton, Trenton, Culbertson, McCook, Cambridge, and Arapahoe, Nebraska. From Arapahoe the Republican River flows in a southeast direction to Harlan County Lake and then east to the figure 1 east edge. East of figure 1 the Republican River flows in an east, south-southeast, east, and south-southeast direction to join the east-oriented Kansas River. The Kansas River joins the Missouri River at Kansas City, Missouri. The Missouri River after flowing in a south-southeast direction to Kansas City turns at Kansas City to flow in an east-southeast direction across Missouri to join the south-oriented Mississippi River at Saint Louis, Missouri. Beaver Creek originates near the figure 1 southwest corner and flows in a northeast and east-northeast direction to Atwood, Ludell, Herndon, Traer, and Cedar Bluffs, Kansas and then to Danbury, Lebanon, Wilsonville, Beaver City, and Stamford, Nebraska before joining the Republican River near Orleans, Nebraska. The Republican River-Beaver Creek drainage divide area in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas is located south of the Republican River segment from Stratton to Cambridge, Nebraska and north of the Beaver Creek segment from Atwood to Wilsonville. The Republican River-Prairie Dog Creek drainage divide area in Furnas and Harlan Counties, Nebraska and Norton and Phillips Counties, Kansas; the Red Willow Creek-Blackwood Creek drainage divide area in Perkins, Lincoln, Hayes, Hitchcock, and Red Willow Counties, Nebraska; and Frenchman Creek-Republican River drainage divide area in Chase, Hayes, Dundy, and Hitchcock Counties, Nebraska essays describe nearby drainage divide areas and can be found under Republican River on the sidebar category list. Hundreds of Missouri River drainage basin landform origins research project essays collectively have presented significant evidence for massive south-oriented floods, which flowed across Nebraska and into Kansas. Flood waters were probably derived from a rapidly melting North American ice sheet and present day Missouri River tributary valleys were eroded headward in an identifiable sequence to capture the south-oriented flood flow and to divert flood waters to what was then the newly eroded Missouri River valley. Evidence presented in this essay demonstrates the deep Beaver Creek valley eroded headward to capture south-oriented flood flow, which was subsequently beheaded by headward erosion of the deep Republican River valley.

Republican River-Beaver Creek drainage divide area detailed location map

Figure 2: Republican River-Beaver Creek drainage divide area detailed location map. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 2 provides a detailed location map for the Republican River-Beaver Creek drainage divide area in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas. Hitchcock and Red Willow are Nebraska counties and the county boundaries are shown. Rawlins and Decatur are Kansas County names. The Republican River flows from Benkelman, Nebraska near the figure 2 west center edge in an east-northeast direction to Stratton, Trenton, and Culbertson in Hitchcock County and then to McCook, Red Willow, Indianola, and Bartley in Red Willow County and finally to Cambridge, Holbrook and Artapahoe in Furnas County (the Nebraska county east of Red Willow County). Beaver Creek flows in a northeast direction to the Rawlins County southwest corner and then to Atwood, Ludell, and Herndon before flowing across the Decatur County northwest corner. Once in Nebraska Beaver Creek flows across the Red Willow County southeast corner and then to Wilsonville and Hendley in southern Furnas County. East of figure 2 Beaver Creek joins the Republican River. Driftwood Creek is an important northeast-oriented Republican River tributary located in southeast Hitchcock County and southwest Red Willow County. Driftwood Creek joins the Republican River near McCook in Red Willow County. The northeast-oriented South Fork Driftwood Creek originates in northern Rawlins County and joins the east-northeast oriented North Fork Driftwood Creek in southern Hitchcock County. Note south-southeast oriented Beaver Creek and Driftwood Creek tributaries and also north-northwest oriented Republican River tributaries. Topographic maps below better illustrate the tributaries, although the figure 2 tributaries and their orientations provide evidence the Beaver Creek, Driftwood Creek, and Republican River valleys eroded headward in sequence to capture multiple south-southeast oriented flood flow channels such as those found in a south-southeast oriented anastomosing channel complex. Beaver Creek valley headward erosion captured the south-southeast oriented flood flow first and south-southeast oriented tributary valleys eroded headward along the flood flow channels. Next Driftwood Creek valley headward erosion captured the south-southeast oriented flood flow and beheaded flood flow routes to the newly eroded Beaver Creek valley. Finally Republican River valley headward erosion beheaded the south-southeast oriented flood flow channels to the newly eroded Driftwood Creek valley. Flood waters on north ends of beheaded flood flow channels reversed flow direction to erode north-oriented Republican River tributary valleys and to create the Republican River-Driftwood Creek drainage divide.

Republican River-Beaver Creek drainage divide area in eastern Red Willow County

Figure 3: Republican River-Beaver Creek drainage divide area in eastern Red Willow County. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the Republican River-Beaver Creek drainage divide area in eastern Red Willow County (and also in western Furnas County). Indianola is the town located in the figure 3 northwest corner. Wilsonville is the town located in the figure 3 southeast quadrant. The east-northeast oriented Republican River is located near Indianola and flows along the figure 3 north margin (west half). Beaver Creek flows in an east direction along the figure 3 south margin (west half) and then turns to flow in a northeast and east direction to Wilsonville and to the figure 3 east edge. Note north-oriented Bogus Canyon in the figure 3 northeast quadrant. The north-south line immediately east of Bogus Canyon is the Red Willow County-Furnas County boundary, with Red Willow County west of the boundary line. Note how Beaver Creek has well-developed south, south-southeast, and southeast oriented tributaries from the north. Note also the north-oriented Republican River tributaries. Many of the north-oriented Republican River tributaries have northwest-oriented tributaries and/or have north-northwest oriented headwaters and/or valley segments. The north-oriented Republican River tributaries also have some northeast-oriented tributaries and/or valleys segments. A close look at the Republican River-Beaver Creek drainage divide reveals shallow north-south oriented through valleys linking north-oriented Republican River tributary valleys with south-oriented Beaver Creek tributary valleys. The through valleys provide evidence of multiple south-oriented flood flow channels such as might be found in a south-oriented anastomosing channel complex. The flood flow channels were eroded by flood waters flowing to what were then actively eroding south-oriented Beaver Creek tributary valleys. The tributary valleys had eroded headward from what was then the newly eroded Beaver Creek valley. At that time the deep Republican River valley did not exist and flood waters were moving on a topographic surface at least as high the present day Republican River-Beaver Creek drainage divide. Headward erosion of the deep Republican River valley then beheaded the south-oriented flood flow channels one channel at a time from east to west. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Republican River valley. Because flood flow channels were anastomosing reversed flow on a newly reversed channels could capture yet to be beheaded flood flow from channels further to the west. With the aid of such captured flood flow the reversed flow eroded the north-oriented Republican River tributary valleys.

Republican River-Beaver Creek drainage divide area south and east of McCook, Nebraska

Figure 4: Republican River-Beaver Creek drainage divide area south and east of McCook, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 4 illustrates the Republican River-Beaver Creek drainage divide area south and east of McCook, Nebraska and is located west and south of the figure 3 map area (and includes overlap areas with figure 3). McCook is the city located in the figure 4 northwest corner and the Republican River flows in an east-northeast direction across the figure 4 northwest quadrant near McCook. Danbury is the much smaller town located near the figure 4 south edge (in the southeast quadrant) and Beaver Creek flows in a northeast and east direction near Danbury. Note the southeast and south-southeast oriented Beaver Creek tributaries. Also note the north and north-northwest oriented Republican River tributaries. Again some of the north-oriented tributaries have northeast and even east oriented valley segments and/or tributaries, but the predominate direction is north or north-northwest. Again there are numerous shallow north-south oriented through valleys crossing the Republican River-Beaver Creek drainage divide. The through valleys were eroded by a south or south-southeast oriented complex of anastomosing flood flow channels moving flood waters to what were then actively eroding southeast and south-southeast oriented Beaver Creek tributary valleys. These tributary valleys had eroded headward from what was then the newly eroded Beaver Creek valley. Headward erosion of the deep east-oriented Republican River valley had not yet reached the figure 4 map area and flood waters were flowing on a topographic surface at least as high as the present day Republican River-Beaver Creek drainage divide. Headward erosion of the deep Republican River valley beheaded the south-oriented flood flow channels one channel at a time from east to west. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Republican River valley. With the aid of captured flood flow from yet to beheaded flood flow channels further to the west the reversed flow eroded the north-oriented Republican River tributary valleys and created the Republican River-Beaver Creek drainage divide. Northeast and east oriented valley segments were probably eroded by movements of captured yet to be beheaded flood flow moving in a northeast or east direction to newly beheaded and reversed flood flow channels.

Detailed map of Republican River-Beaver Creek drainage divide area south of McCook

Figure 5: Detailed map of Republican River-Beaver Creek drainage divide area south of McCook. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 provides a detailed map of the Republican River-Beaver Creek drainage divide area almost directly south of the McCook Municipal Airport seen in the figure 4 northwest corner area. The highway in the figure 5 southwest corner may help in locating the figure 5 area in the less detailed figure 4 map area above. The highway crosses the Republican River-Beaver Creek drainage divide in the section 10 northwest corner. The drainage divide can then be followed in a northeast direction across section 2 and into southern section 36. From section 36 the drainage divide continues in an east-southeast direction to the section 6 and 5 border and then in a northeast direction to the figure 5 east edge. Note how the drainage divide is crossed by multiple, but shallow north-south oriented through valleys. Compared to valley depths on either side the through valleys are not deep, but the through valleys do provide evidence of drainage routes that existed prior to headward erosion of the present day deep valleys. At the time the through valleys were eroded there was no Republican River valley north of the figure 5 map area and none of the present day Missouri River tributary valleys north of the figure 5 map area existed either. Flood waters were able to flow south to the figure 5 map area from a rapidly melting ice sheet across a topographic surface that has since been largely, if not completely, removed by flood water erosion. The east and east-northeast oriented Beaver Creek valley eroded headward into the figure 5 map area to capture south-oriented flood flow and to divert flood waters east to the newly eroded Republican River valley (east of the figure 5 map area). The newly eroded Republican River valley then moved the captured flood waters to the newly eroded Kansas River valley, which in turn moved the captured flood waters to what was then the newly eroded Missouri River valley. Headward erosion of the deep Republican River valley north of the figure 5 map area next captured the south-oriented flood flow and moved the flood waters more directly east and southeast. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Republican River valley. The reversed flow eroded the north-oriented Republican River tributary valleys and created the Republican River-Beaver Creek drainage divide.

Republican River-Driftwood Creek drainage divide area

Figure 6: Republican River-Driftwood Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 illustrates the Republican River-Driftwood Creek drainage divide area west of the figure 4 map area. McCook, Nebraska is located just east of the figure 6 northeast corner. The Republican River is located in the figure 6 north half and flows in an east-northeast direction from the figure 6 west edge to near the figure 6 north edge and then turns to flow in an east-southeast direction to figure 6 east edge. Trenton is the town located in the Republican River valley near the figure 6 west edge and Culbertson is the Republican River valley town located near where the Republican River turns from flowing in an east-northeast direction to flowing in an east-southeast direction. Driftwood Creek flows in a northeast direction from the figure 6 south center edge to the figure 6 east center edge and joins the Republican River just east of the figure 6 map area. Note how there is a relatively smooth southeast-oriented erosion surface leading from the Republican River-Driftwood Creek drainage divide to the Driftwood Creek valley floor. Southeast-oriented Driftwood Creek tributary valleys have been eroded into this southeast-oriented erosion surface. Note also the north oriented Republican River tributaries north of the drainage divide. Many are oriented in a north-northwest direction and/or have northwest-oriented tributaries. Also note north-oriented Driftwood Creek tributaries in the figure 6 southeast quadrant and contrast the north- and northeast-facing valley slopes with the southeast-facing valley slopes. Like areas illustrated in previous figures the figure 6 evidence is best explained in the context of immense south or southeast oriented flood flow, which originally flowed on a topographic surface at least as high as the highest figure 6 elevations today. The deep northeast-oriented Driftwood Creek valley eroded headward into the figure 6 map area from what was then the actively eroding Republican River valley head. Headward erosion of the deep Driftwood Creek valley beheaded flood flow channels moving flood water to what were then south-oriented Beaver Creek tributary valleys (see figure 7 below) and flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Driftwood Creek valley. At the same time much larger volumes of southeast-oriented flood flow was eroding the southeast-facing Driftwood Creek valley northeast wall and southeast-oriented flood flow channels eroded headward along major southeast-oriented flood flow routes. Headward erosion of the deep Republican River valley next beheaded and reversed the southeast-oriented flood flow, which eroded the north-oriented Republican River tributary valleys and created the Republican River-Driftwood Creek drainage divide. Note numerous shallow through valleys crossing the Republican River-Driftwood Creek drainage divide, which provide evidence of southeast-oriented flood flow channels, which once moved flood water to the newly eroded Driftwood Creek valley.

Driftwood Creek-Beaver Creek drainage divide area

Figure 7: Driftwood Creek-Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 illustrates the Driftwood Creek-Beaver Creek drainage divide area south of the figure 6 map area and includes overlap areas with figure 6. The west to east oriented Nebraska-Kansas state line is located just north of the figure 7 center. Driftwood Creek is located in the figure 7 northwest quadrant and flows in a northeast direction to the figure 7 north edge (west half). Driftwood Creek is formed at the confluence of northeast-oriented South Fork Driftwood Creek and east-oriented North Fork Driftwood Creek located in Nebraska north of the state line. Herndon, Kansas is the town located near the figure 7 south center edge. Beaver Creek is located in the figure 7 southeast quadrant and flows in an east-northeast direction from Herndon to the figure 7 east edge. Note again the southeast and south-southeast oriented Beaver Creek tributaries. Also note north and north-northwest oriented Driftwood Creek tributaries. Close inspection of the Driftwood Creek-Beaver Creek drainage divide again reveals numerous north-south oriented shallow through valleys linking the north-oriented Driftwood Creek tributary valleys with the south-oriented Beaver Creek tributary valleys. The Driftwood Creek-Beaver Creek drainage divide history is similar to the Republican River-Driftwood Creek drainage divide history described in figure 6, except the Driftwood Creek-Beaver Creek drainage divide was created before the Republican River-Driftwood Creek drainage divide was created. Immense south-southeast oriented flood flow initially moved across the figure 7 map area on a topographic surface at least as high as the present day Driftwood Creek-Beaver Creek drainage divide. Through valleys across the drainage divide were eroded by anastomosing south-southeast oriented flood flow channels moving flood waters to what were then actively eroding south-southeast oriented Beaver Creek tributary valleys. Headward erosion of the deep Driftwood Creek valley then beheaded the south-oriented flood flow channels in sequence from east to west. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north, to erode north-oriented Driftwood Creek tributary valleys, and to create the Driftwood Creek-Beaver Creek drainage divide.

Republican River-North Fork Driftwood Creek drainage divide area

Figure 8: Republican River-North Fork Driftwood Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 8 illustrates the Republican River-North Fork Driftwood Creek drainage divide area west and slightly south of the figure 6 map area and includes overlap areas with figure 6. The west to east oriented Nebraska-Kansas state line is located near the figure 8 south margin. Trenton, Nebraska is the town located near the figure 8 northeast corner. Swanson Lake is the reservoir located in the east-northeast oriented Republican River valley. Stratton, Nebraska is the town located in the Republican River valley west of Swanson Lake. The North Fork Driftwood Creek flows in an east-northeast from the figure 8 south center edge area into the figure 8 southeast quadrant and then turns to flow in an east direction to the figure 8 east edge. Note how the North Fork Driftwood Creek has south-southeast oriented tributaries from the north and north-northwest oriented tributaries from the south. Also note how many of the north-oriented Republican River tributaries have north-northwest valley segments and/or tributaries. Close inspection of the figure 8 Republican River-North Fork Driftwood Creek drainage divide again reveals numerous shallow north-south oriented through valleys linking valleys of north-oriented Republican River tributaries with valleys of south-oriented North Fork Driftwood Creek tributaries. The through valleys again were eroded by south-oriented anastomosing flood flow channels moving flood water to what were then actively eroding south-southeast oriented North Fork Driftwood Creek tributary valleys. At that time the figure 8 Republican River valley did not exist and the North Fork Driftwood Creek valley was eroding headward across the figure 8 map area. Headward erosion of the deep east-northeast oriented Republican River valley then beheaded the south-southeast oriented flood flow channels in sequence (from east to west). Flood waters on north ends of beheaded flood flow routes reversed direction to flow north to the newly eroded and deep Republican River valley. The reversed flood flow, with the aid of captured yet to be beheaded flood flow from channels further to the west, eroded the north-oriented Republican River tributary valleys and created the Republican River-North Fork Driftwood Creek drainage divide.

North Fork Driftwood Creek-Beaver Creek drainage divide area

Figure 9: North Fork Driftwood Creek-Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 9 illustrates the North Fork Driftwood Creek-South Fork Driftwood Creek-Beaver Creek drainage divide south of the figure 8 map area and includes overlap areas with figure 8. Ludell, Kansas is the small town located near the figure 9 south edge (east half). Note the west to east oriented Nebraska-Kansas state line located near the figure 9 north edge. Beaver Creek flows in an east-northeast direction across the figure 9 southeast corner and can be seen flowing in an east direction along the figure 9 south margin in the figure 9 southwest quadrant. Note south-southeast oriented Beaver Creek tributaries. The South Fork Driftwood Creek originates in the figure 9 southwest quadrant and flows in a northeast direction across the figure 9 center area to the figure 9 north edge (east half). Note southeast and south-southeast oriented and north-northwest oriented South Fork Driftwood Creek tributaries. Wildhorse Canyon is a northeast-oriented North Fork Driftwood Creek tributary located in the figure 9 north center area and draining to the figure 9 north edge. The North Fork Driftwood Creek flows in a northeast direction across the figure 9 northwest corner area. Note north, north-northeast, and north-northwest oriented North Fork tributaries. Study of the South Fork Driftwood Creek-Beaver Creek drainage divide area reveals numerous north-south oriented through valleys similar to through valleys seen in earlier figures in this essay. Figure 10 below provides a detailed map of South Fork Driftwood Creek-Beaver Creek drainage divide area to better illustrate the through valleys. Through valleys can also be seen crossing the Wildhorse Canyon-South Fork Driftwood Creek drainage divide. Through valleys are not easily identified on the North Fork Driftwood Creek-South Fork Driftwood Creek drainage divide south and west of the Wildhorse Canyon head. That drainage divide appears to be a relatively smooth erosion surface, which was probably eroded by sheet flow moving first to what was then the newly eroded Beaver Creek valley and which was subsequently captured by headward erosion of the South Fork Driftwood Creek valley. The figure 9 drainage history is similar to the drainage histories determined for the previous figures. First headward erosion of the deep Beaver Creek valley captured the massive south-southeast oriented flood flow. Next headward erosion of the South Fork Driftwood Creek valley captured flood flow routes to actively eroding south-southeast oriented Beaver Creek tributary valleys. Next headward erosion of the Wildhorse Canyon valley beheaded some flood flow routes to the newly eroded South Fork Driftwood Creek valley. Finally headward erosion of the North Fork Driftwood Creek valley beheaded flood flow to the newly eroded Wildhorse Canyon valley, the newly eroded South Fork Driftwood Creek valley (west of the Wildhorse Canyon valley head), and the newly eroded Beaver Creek valley (west of the South Fork Driftwood Creek valley head).

Detailed map of South Fork Driftwood Creek-Beaver Creek drainage divide area

Figure 10: Detailed map of South Fork Driftwood Creek-Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 10 provides a detailed map of the South Fork Driftwood Creek-Beaver Creek drainage divide seen in less detail in figure 9 above. The figure 10 drainage divide area shown is almost directly north from Ludell. North and northwest valleys in the figure 10 north half drain to northeast-oriented South Fork Driftwood Creek. South and southeast oriented valleys in the figure 10 south half drain to east-northeast oriented Beaver Creek. Figure 10 illustrates the shallow north-south oriented through valleys linking north-oriented South Driftwood Creek tributary valleys with south-oriented Beaver Creek tributary valleys. Especially well-defined through valleys can be seen in sections 35, 36, and 30. Floors of these deeper through valleys are 50 feet, or more, lower in elevation than tops of surrounding hills. The through valleys provide evidence of multiple south-oriented flood flow channels to what were then actively eroding south-oriented Beaver Creek tributary valleys at a time when the deep northeast-oriented South Fork Driftwood Creek valley did not exist. At that time the deep North Fork Driftwood Creek valley and the deep Republican River valley further to the north did not exist either. Flood waters were flowing to what was then the newly eroded Beaver Creek valley. Headward erosion of the deep northeast-oriented South Fork Driftwood Creek valley then beheaded the south-oriented flood flow channels in sequence from the east to the west. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north and to erode north-oriented South Fork Driftwood Creek tributary valleys. Headward erosion of the deep North Fork Driftwood Creek valley next repeated the process. And (in the context of the drainage divide area discussed here) headward erosion of the deep Republican River valley still further to the north repeated the process again. Headward erosion of Missouri River tributary valleys such as the east-oriented Platte River valley still further to north repeated the process over and over again until the present day Missouri River valley and tributary valley system had fully evolved.

Additional information and sources of maps

This essay has only provided a sample of the drainage divide evidence supporting the “thick ice sheet that melted fast” geomorphology paradigm. Many additional examples could be provided, especially by using more detailed topographic maps. Readers are encouraged to look at mosaics of detailed topographic maps to see the abundance of supporting data. Maps used in this study were created by the United States Geological Survey and can be purchased in hard copy from the United States Geological Survey or from dealers offering United States Geological Survey maps. Hard copy maps can also be observed at United States Geological Survey map depositories located in major research libraries and elsewhere throughout the United States and in other countries. Illustrations used in this essay were created using National Geographic Society TOPO software and digital data. National Geographic Society digital maps can be purchased from the National Geographic Society or from dealers offering National Geographic Society digital maps.