Abstract:

The Republican River-Little Beaver Creek drainage divide area in Dundy and Hitchcock Counties, Nebraska and Cheyenne and Rawlins Counties, Kansas was eroded by immense south-southeast or southeast oriented floods. Flood waters were probably derived from a rapidly melting thick North American ice sheet and flowed across Nebraska and into Kansas. Headward erosion of the deep northeast-oriented Little Beaver Creek valley from what was then the newly eroded Beaver Creek valley beheaded flood flow to the newly eroded northeast-oriented Beaver Creek valley, which had eroded headward from what was then the actively eroding Republican River valley head. Headward erosion of the east and east-northeast oriented North Beaver Creek valley then beheaded flood flow to the newly eroded Little Beaver Creek valley. Next headward erosion of the Republican River-Driftwood Creek-North Fork Driftwood Creek valley beheaded flood flow to some of what were then actively eroding southeast-oriented North Beaver Creek tributary valleys. Republican River and South Fork Republican River valley headward erosion next beheaded and reversed flood flow to erode the north-oriented Burntwood Creek, Big Timber Creek, and other tributary valleys. Headward erosion of the North Fork Republican River-Arikaree River valley then beheaded flood flow to the newly eroded South Fork Republican River valley and its actively eroding southeast-oriented tributary valleys. Evidence for this flood origin interpretation consists of present day valley positions and orientations and of multiple shallow through valleys crossing some drainage divides.

Preface:

• The purpose of this essay is to use topographic map interpretation methods to explore Republican River-Little Beaver Creek drainage divide area landform origins in Dundy and Hitchcock Counties, Nebraska and Cheyenne and Rawlins 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-Little Beaver Creek drainage divide area landform origins in Dundy and Hitchcock Counties, Nebraska and Cheyenne and Rawlins Counties, Kansas will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm. This essay is included in the Missouri River drainage basin landform origins research project essay collection.

Republican River-Little Beaver Creek drainage divide area location map

Figure 1: Republican River-Little 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-Little Beaver Creek drainage divide area location map. Colorado is the state in the figure 1 western half. Nebraska is located in the figure 1 northeast quadrant and Kansas is located in the southeast quadrant. The South Fork Republican River flows from the figure 1 southwest corner to Bonny Reservoir near Hale, Colorado before flowing across the Kansas northwest corner to join the North Fork Republican River at Benkelman, Nebraska. From Benkelman the Republican River flows in an east-northeast direction to Max, Stratton, Trenton, Mccook, and Cambridge before reaching the figure 1 east edge. The North Fork Republican River originates southwest of Wray, Colorado and flows in a northeast and then southeast direction to join the northeast-oriented Arikaree River at Haigler, Nebraska. Little Beaver Creek originates north of Burlington, Colorado and flows in a northeast direction to join northeast-oriented Beaver Creek near Atwood, Kansas. Beaver Creek then flows in an east-northeast direction to Danbury and Wilsonville, Nebraska before reaching the figure 1 east edge. East of figure 1 Beaver Creek joins the Republican River and the Republican River then flows in an east and southeast direction to eventually join the east-oriented Kansas River, which flows to the Missouri River at Kansas City, Missouri. The Republican River-Little Beaver Creek drainage divide area illustrated and discussed in this essay is located south of North Fork Republican River-Republican River segment extending from the Colorado border to Stratton, Nebraska and north of the Little Beaver Creek segment extending from the Colorado border to near McDonald, Kansas. The Republican River-Beaver Creek drainage divide area in Hitchcock and Red Willow Counties, Nebraska and Rawlins and Decatur Counties, Kansas and the Frenchman Creek-Republican River drainage divide area in Chase, Hayes, Dundy and Hitchcock Counties, Nebraska essays address nearby drainage divide areas and can be under Republican River on the sidebar category list. Hundreds of Missouri River drainage basin landform origins research project essays collectively provide very significant evidence for immense south-oriented floods that once flowed across Nebraska and into Kansas. The Republican River valley and its northeast and east-oriented Beaver Creek and Little Beaver Creek valleys eroded headward into the figure 1 map area to capture south-oriented flood flow and to divert flood waters east and southeast to what was then the newly eroded Missouri River. Valleys eroded headward into and across the figure 1 map area in sequence with the Beaver Creek valley eroding headward slightly in advance of the Little Beaver Creek valley, which beheaded south-oriented flood flow to the newly eroded Beaver Creek valley. Next South Fork Republican River valley headward erosion beheaded south-oriented flood flow to the newly eroded Little Beaver Creek valley. The North Fork Republican River-Arikareee Creek valley then beheaded south-oriented flood flow to the newly eroded South Fork Republican River valley. Finally North Fork Republican River valley headward erosion beheaded south-oriented flood flow to eastern segments of the newly eroded Arikaree River valley.

Republican River-Little Beaver Creek drainage divide area detailed location map

Figure 2: Republican River-Little 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 more detailed location map for the Republican River-Little Beaver Creek drainage divide area in Dundy and Hitchcock Counties, Nebraska and Cheyenne and Rawlins Counties, Kansas. Dundy and Hitchcock are Nebraska county names and county boundaries are shown. Cheyenne and Rawlins are Kansas counties. Colorado is located west of Dundy and Cheyenne Counties. The South Fork Republican River flows from Bonny Reservoir in the figure 2 southwest corner area in a northeast direction to St Francis in Cheyenne County and then to join the North Fork Republican River at Benkelman in southern Dundy County. The North Fork Republican River flows in a northeast direction from the figure 2 west center edge to Wray, Colorado and then in a southeast direction to join the northeast-oriented Arikaree River near Haigler Nebraska (located in the Dundy County southwest corner) and then flows in an east direction to join the South Fork Republican River at Benkelman. From Benkeleman the Republican River flows in an east-northeast direction across Hitchcock County to McCook and then to the figure 2 east edge. Little Beaver Creek flows in a northeast, east-northeast, northeast direction into and across southern Cheyenne County and then in a northeast direction to join northeast-oriented Beaver Creek near Atwood in central Rawlins County. Note how the North Fork Republican River-Republican River has a number of southeast and south-southeast oriented tributaries and also has some north and north-northwest oriented tributaries. Burntwood Creek is a named north-oriented Republican River tributary near the Dundy-Hitchcock County border. East-oriented Hackberry Creek is an east-oriented South Fork Republican River tributary in northern Cheyenne County. Other South Fork Republican River tributaries shown are southeast-oriented and north-oriented, with some being north-northwest oriented. Delay Creek and Big Timber Creek are two named South Fork Republican River tributaries in northeast Cheyenne County. East-northeast and southeast oriented North Beaver Creek in Rawlins County is the only named Little Beaver Creek tributary shown. Southeast-oriented tributary valleys suggest the Republican River valley and its tributary valleys eroded headward across multiple southeast-oriented flood flow channels. North and north-northwest oriented tributary valleys were eroded by reversals of flood flow on north ends of beheaded flood flow routes. South and southeast oriented flood flow across the figure 2 map area probably moved in anastomosing channels and headward erosion of deep east- and northeast-oriented valleys would have beheaded the south- or southeast-oriented flood flow channels one channel at a time from east to west. Reversed flow on newly beheaded flood flow channels captured yet to be beheaded flood flow from channels further west. Such captures of yet to be beheaded flood flow provided the volumes of flood water required to erode significant north-oriented tributary valleys.

Republican River-North Driftwood Creek drainage divide area

Figure 3: Republican River-North Driftwood Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 illustrates the Republican River-North Driftwood Creek drainage divide area in southwest Hitchcock County, Nebraska and also the Republican River-Burntwood Creek drainage divide in southeast Dundy County, Nebraska. Max, Nebraska is the town located in the figure 3 northwest corner. The Republican River flows in an east-northeast direction along the west half of the figure 3 north edge area. North Driftwood Creek flows north from the figure 3 south center edge to near the west to east oriented Kansas-Nebraska state line and then flows in an east and northeast direction to the figure 3 east edge (south half). East of the figure 3 map area North Driftwood Creek flows in an east-northeast direction to northeast-oriented Driftwood Creek, which eventually flows to the Republican River. Burntwood Creek flows in a north direction into the figure 3 southwest corner and then turns to flow in an east and east-northeast direction before turning to flow straight north along the Dundy-Hitchcock County border to join the east-northeast oriented Republican River. Boston Canyon is the named north-northwest oriented Republican River tributary south of Max. Note how Boston Canyon and the unnamed north-northwest Republican River tributary west of Boston Canyon are linked by shallow through valleys to east- and southeast-oriented Burntwood Creek tributaries. The shallow through valleys and the barbed Republican River tributaries are evidence of south-southeast oriented flood flow channels beheaded and reversed by headward erosion of the deep Republican River valley. Note also the northwest-oriented Burntwood Creek tributary located near the common corner of Dundy, Hitchcock, and Rawlins Counties. That northwest-oriented tributary is linked by shallow through valleys with an east-oriented North Driftwood Creek tributary. Further note how the east and east-northeast oriented North Driftwood Creek valley is linked by shallow through valleys with unnamed north and north-northwest oriented tributary valleys. What has happened here is the North Fork Driftwood Creek valley eroded headward into the figure 3 map area to capture south-oriented flood flow prior to headward erosion of the deep Republican River valley. At that time flood waters were flowing in multiple south-oriented anastomosing flood flow channel on a topographic surface at least as high as the highest figure 3 elevations today. Headward erosion of the deep Republican River valley then beheaded the south-oriented flood flow channels in sequence from east to west. Flood waters on north ends of newly beheaded flood flow channels reversed flow direction to flow north and eroded the north-oriented Republican River tributary valleys. Reversed flow in the newly beheaded Burntwood Creek channel captured significant flood flow from flood flow channels west of the actively eroding Republican River valley head and was able to capture what had been captured east-oriented flood flow moving to the previously eroded North Driftwood Creek valley. The northwest-oriented Burntwood Creek tributary valley was eroded by a reversal of the east-oriented flood flow moving to that previously eroded North Driftwood Creek valley.

North Fork Republican River-South Fork Republican River drainage divide area

Figure 4: North Fork Republican River-South Fork Republican River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 uses reduced size maps to illustrate the North Fork Republican River-South Fork Republican River drainage divide area west and south of the figure 3 map area. Benkelman, Nebraska is the town located near the figure 4 north edge (east half). Parks is the much smaller town located near the figure 4 northwest corner. The North Fork Republican River flows in an east direction from Parks to join the northeast-oriented South Fork Republican River near Benkelman. North and east oriented Burntwood Creek headwaters are located near the Cheyenne-Rawlins County line near the figure 4 east center edge area. West of the Burntwood Creek headwaters is north-northwest oriented Jones Canyon, which drains to the Republican River east and north of Benkelman (and north of the figure 4 map area). West of Jones Canyon is north, northeast, northwest, and north oriented Big Timber Creek, which joins the South Fork Republican River just south of Benkelman. West and northwest of Big Timber Creek are several north and north-northwest oriented South Fork Republican River tributaries from the southeast and southeast-oriented South Fork Republican River tributaries from the northwest. The east-oriented South Fork tributary near the figure 4 southwest corner is Hackberry Creek, which is further illustrated in figure 5 below. Note also north-oriented North Fork tributaries and shallow through valleys linking heads of north-oriented North Fork tributary valleys with heads of southeast-oriented South Fork tributary valleys. The through valleys, while shallow, provide evidence flood water flowed in a southeast direction to what was once a newly eroded northeast-oriented South Fork valley prior to headward erosion of the deep east-oriented North Fork valley. Further note northwest and north-northwest oriented Big Timber Creek tributaries. Figure 4 drainage history (at least the history determinable from figure 4 evidence) began with immense south-southeast oriented flood flow moving across the entire figure 4 map area.. Headward erosion of the Republican River valley then beheaded flood flow on the Burntwood Creek alignment east of the figure 4 map area. Flood waters reversed flow direction to flow north and captured yet to be beheaded flood flow from further to west. The process was repeated as Republican River valley headward erosion beheaded the flood flow on the Jones Canyon and Big Timber Creek alignments. Reversed flow on the Big Timber Creek alignment captured flood flow routes further to the west and flood waters, which eroded the northeast-oriented Big Timber Creek valley segment, which in turn beheaded flood flow routes. Flood flow on north ends of those beheaded flood flow routes reversed flow direction to erode north-oriented Big Timber Creek tributary valleys. Next headward erosion of the South Fork Republican River valley beheaded southeast or south-southeast oriented flood flow routes and flood waters on north ends of those beheaded flood flow routes reversed flow direction to erode north-northwest oriented South Fork valleys. The process was repeated as the east-oriented North Fork Republican River valley beheaded and reversed the south-southeast oriented flood flow routes.

North Fork Republican River-Hackberry Creek drainage divide area

Figure 5: North Fork Republican River-Hackberry Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the North Fork Republican River-Hackberry Creek drainage divide area west of the figure 4 map area and includes overlap areas with figure 4. Haigler, Nebraska is the town located in the figure 5 northwest quadrant. Parks is the much smaller town located in figure 5 northeast corner. The North Fork Republican River flows in a southeast direction from the figure 5 northwest corner to Haigler and then turns to flow in an east direction to Parks in the figure 5 northeast corner. The northeast-oriented Arikaree River can be seen joining the North Fork Republican River near Haigler. Hackberry Creek flows in an east direction near the figure 5 south edge and as seen in figure 4 joins the northeast-oriented South Fork Republican River east of the figure 5 map area. Note southeast-oriented Hackberry Creek tributary valleys and also the relatively smooth south to the southeast facing slope of the Hackberry Creek north valley wall. Compare that smooth slope with the rugged topography north of the North Fork Republican River-Hackberry Creek drainage divide. North of the drainage divide northeast, north, and north-northwest oriented tributaries to the east-oriented North Fork Republican River are present. Note shallow through valleys crossing the drainage divide and linking north-oriented tributary valleys with south oriented tributary valleys. Figure 5a below provides a detailed map of the drainage divide to better illustrate the shallow through valleys. The through valleys provide evidence of multiple south-oriented flood flow routes, which once moved large volumes of south- or southeast-oriented flood water to what was then the newly eroded Hackberry Creek valley. Flood waters eroded the Hackberry Creek valley north wall to produce the smooth slope seen today. At that time the North Fork Republican River valley had not been eroded. Subsequent headward erosion of the deep North Fork Republican River valley beheaded and reversed south-oriented flood flow routes to the newly eroded Hackberry Creek valley. The reversal of flood waters eroded the north-oriented North Fork Republican River tributary valleys and created the North Fork Republican River-Hackberry Creek drainage divide. Volumes of reversed flood waters flowing north were significantly less than volumes of flood water flowing south into the Hackberry Creek valley and for that reason the south wall of the North Fork Republican River was not eroded into a smooth north-facing slope similar to the Hackberry Creek valley north wall, but instead presents a much more rugged appearance.

Figure 5a: Detailed map of North Fork Republican River-Hackberry Creek drainage divide area (seen in the figure 5 center) to better illustrate shallow through valleys crossing the drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Arikaree River-Cherry Creek drainage divide area

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

Figure 6 illustrates the Arikaree River-Cherry Creek drainage divide area south and west of the figure 5 map area and includes overlap areas with figure 5. St Francis, Kansas is the town located in the figure 6 southeast corner. The South Fork Republican River flows in a northeast direction near St Francis. Cherry Creek is the east-oriented tributary joining the South Fork Republican River near St Francis. Note deep southeast-oriented Cherry Creek and South Fork Republican River tributary valleys, which have been eroded into a relatively smooth southeast-oriented slope. The east-oriented stream near the figure 6 north edge flowing from the figure 6 north center area to the figure 6 east edge and then to the South Fork Republican River is Hackberry Creek. The northeast-oriented river in the figure 6 northwest corner is the Arikaree River. Note northwest-oriented Arikaree River tributaries from the southeast and north-oriented Hackberry Creek tributaries from the south. Clough Valley is a shallow northwest-southeast oriented through valley linking a northwest-oriented Arikaree River tributary valley with a southeast-oriented Cherry Creek tributary valley. Lansing Valley in the figure 6 southwest corner is a similar northwest-southeast oriented shallow through valley. Other shallow through valleys are present, although are better seen on more detailed maps. The tributary orientations and through valleys that can be seen provide evidence to determine figure 6 drainage history. Figure 6 evidence suggests flood waters were moving in a southeast direction (at least when present day valleys were eroded) and flowed across the entire figure 6 map area. Headward erosion of the deep South Fork Republican River valley captured the flood waters first and the Cherry Creek and Hackberry Creek valleys then eroded headward from the newly eroded South Fork Republican River valley. Headward erosion of the Hackberry Creek valley beheaded and reversed flood flow to the newly eroded South Fork Republican River valley, with reversed flood flow eroding the north-oriented Hackberry Creek tributary valleys. At the same time flood waters moving to the newly eroded South Fork Republican River valley eroded the relatively smooth erosion surface seen today and deep southeast-oriented tributary valleys then eroded headward from the newly eroded South Fork Republican River and Cherry Creek valleys. Headward erosion of the deep northeast-oriented Arikaree River valley next beheaded the southeast-oriented flood flow and flood waters on northwest ends of beheaded flood flow routes reversed flow direction to erode northwest-oriented Arikaree River tributary valleys.

South Fork Republican River-Little Beaver Creek drainage divide area

Figure 7: South Fork Republican River-Little Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 uses reduced size maps to illustrate the South Fork Republican River-Little Beaver Creek drainage divide east and south of the figure 6 map area and includes overlap areas with figure 6. The South Fork Republican River flows in a northeast direction from the figure 7 west center edge area to the figure 7 north edge (west half). St Francis is the town located in the South Fork Republican River valley. McDonald is the smaller town located near the figure 7 east edge (north of the east center edge area) and Bird City is the smaller town located between St Francis and McDonald. The east-northeast and northeast oriented stream flowing from the figure 7 southwest corner area to the figure 7 east center edge area is Little Beaver Creek. The northeast-oriented stream in the figure 7 southeast corner and south and east of Little Beaver Creek is Beaver Creek. Note southeast-oriented South Fork Republican River tributaries in the figure 7 northwest corner and northwest and north-northwest oriented tributaries from the south and east. Little Beaver Creek tributaries with a few exceptions are southeast or south-southeast oriented from the north and northwest and north-northwest oriented from the south and east. Beaver Creek tributaries from the north and west tend to be southeast oriented and from the south and east tend appear to be north-oriented. The South Fork Republican River-Little Beaver Creek drainage divide area appears to be a gently sloping northeast-oriented erosion surface. If northwest-southeast oriented through valleys are present they are not apparent from the figure 7 map evidence. Orientations of major deep northeast-oriented valley tributaries however suggest the deep northeast-oriented valleys eroded headward in sequence to capture massive southeast-oriented flood flow, which deeply eroded the figure 7 map area and which produced the present day gently sloping erosion surface. Headward erosion of the deep northeast-oriented Beaver Creek valley first captured the southeast-oriented flood flow. Little Beaver Creek then beheaded and reversed flood flow routes to the newly eroded Beaver Creek valley. Headward erosion of the deep South Fork Republican River valley next beheaded and reversed southeast-oriented flood flow to the newly eroded Little Beaver Creek valley. Reversed flood flow eroded north-northwest oriented South Fork Republican River tributary valleys and created the South Fork Republican River-Little Beaver Creek drainage divide.

South Fork Republican River-Big Timber Creek drainage divide area

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

Figure 8 illustrates the South Fork Republican River-Big Timber Creek drainage divide area north of the figure 7 map area and south of the figure 4 map area and includes overlap areas with both figures 4 and 7. Bird City, Kansas is the town located near the figure 8 south edge. The South Fork Republican River flows in a northeast direction from the figure 8 west edge to the figure 8 north edge (west half). Big Timber Creek originates in the figure 8 south center area (northwest from Bird City) and flows north and northeast to the figure 8 north edge (east half). Wolfe Canyon and Sawyer Canyon are the two named north-oriented Big Timber Creek tributaries. Note other unnamed north and north-northwest oriented Big Timber Creek tributaries. Valley Creek is the northwest-oriented South Fork Republican River tributary in the figure 8 southwest quadrant. North-northwest oriented Bluff Creek is the named South Fork Republican River tributary in the figure 8 northwest quadrant. Named South Fork Republican River tributaries near the figure 8 north edge from west to east are north-northwest oriented Delay Creek, north-oriented Devils Canyon, and north-oriented Sleepy Canyon. A close look at the South Fork Republican River-Big Timber drainage divide does reveal some shallow through valleys linking the north-oriented Delay Creek, Devils Canyon, and Sleepy Canyon valleys with the northeast-oriented Big Timber Creek valley. Figure 9 below provides a detailed map of that drainage divide area to better illustrate the shallow through valleys. The Figure 8 map evidence suggests a drainage history that began with south-southeast oriented flood water flowing across the entire figure 8 map area. Headward erosion of the northeast-oriented Big Timber Creek valley captured the south-southeast oriented flood flow and flood waters on north ends of beheaded flood flow routes reversed flow direction to erode north and north-northwest oriented Big Timber Creek tributary valleys. Apparently South Fork Republican River valley headward erosion beheaded south-southeast oriented flood flow to the newly eroded Big Timber Creek valley before any significant southeast-oriented tributary valleys could erode headward from what was then the newly eroded Big Timber Creek valley. Headward erosion of the South Fork Republican River then beheaded and reversed the south-southeast oriented flood flow routes and flood waters on north ends of the beheaded flood flow routes reversed flow direction to flow north to the newly eroded South Fork Republican River. The reversed flood flow eroded the north and north-northwest oriented South Fork Republican River tributary valleys and created the South Fork Republican River-Big Timber Creek drainage divide.

Detailed map of Devils Canyon-Big Timber Creek drainage divide area

Figure 9: Detailed map of Devils Canyon-Big Timber Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 provides a detailed map of the Devils Canyon-Big Timber Creek drainage divide area seen in less detail in figure 8 above. Big Timber Creek flows in a north-northeast direction in section 15 near the figure 9 south center edge and then turns to flow in an east-northeast and east direction across section 11 before turning to flow in a north-northeast direction to the figure 9 east center edge. Devils Canyon is the labeled north-oriented valley in sections 8, 5, and 32 near the figure 9 west edge. East of Devils Canyon is north-oriented Sleepy Canyon (only the word Canyon shows) in sections 4 and 33. Note shallow northwest-southeast oriented through valleys in sections 17 (south of section 8) and 9 linking the north-oriented Devils Canyon valley with east- and east-southeast oriented Big Timber Creek tributary valleys. Also note in the area of the corner between sections 3, 4, 9, and 10 a large, but shallow northwest-southeast oriented through valley linking the north-oriented Sleepy Canyon valley with short southeast-oriented Big Timber Creek tributary valleys. The shallow through valleys provide evidence of multiple northwest-southeast oriented flood flow channels such as might be found in south or south-southeast oriented anastomosing channel complex. The figure 9 evidence confirms the flood origin interpretation suggested in the figure 8 discussion. Headward erosion of the deep Big Timber Creek valley captured south or south-southeast oriented flood water moving across the entire figure 9 map area. Southeast, east-southeast, and east oriented tributary valleys did erode headward from the newly eroded Big Timber Creek valley. However, headward erosion of the deep South Fork Republican River valley north of the figure 9 map area beheaded (in sequence from east to west) the south-oriented flood flow routes to what were then the actively eroding Big Timber Creek tributary valleys. Flood waters on north ends of the beheaded flood flow routes reversed flow direction to erode the north-oriented Sleepy Canyon, Devils Canyon, and other north and north-northwest oriented South Fork Republican River tributary valleys. The reversal of flood flow was responsible for creating the South Fork Republican River-Big Timber Creek drainage divide.

Big Timber Creek-North Beaver Creek drainage divide area

Figure 10: Big Timber Creek-North Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 10 illustrates the Big Timber Creek-North Beaver Creek drainage divide east and north of the figure 7 map area and south of the figure 3 map area and includes overlap areas with figure 7. McDonald is the town located near the figure 10 south center edge. Big Timber Creek flows in a north direction in the figure 10 northwest corner area. Note north-northwest oriented Big Timber Creek tributaries. Jones Canyon is the north-northwest oriented valley labeled “Canyon” east of Big Timber Creek. The north-northeast oriented stream in the figure 10 north center area is the East Fork of Burntwood Creek, which was seen in figure 3. Note north-northwest oriented tributaries to north-northeast oriented East Fork Burntwood Creek. The north-northeast and northeast oriented stream east of the East Fork Burntwood Creek is North Fork Driftwood Creek and the northeast and north oriented stream in the figure 10 northeast corner area is a tributary to the North Fork Driftwood Creek. North Fork Driftwood Creek was also seen in figure 3. Note north-northwest oriented tributaries to the North Driftwood Creek and its northeast-oriented tributary.  Little Beaver Creek is the northeast-oriented stream in the figure 10 southeast corner. The east and east-northeast oriented stream originating north of McDonald is North Beaver Creek, which joins Little Beaver Creek east of the figure 10 map area. Note the southeast-oriented tributaries to east and east-northeast North Beaver Creek. Figure 10 map evidence does not show any through valleys linking the north-oriented Republican River tributary valleys with the east- and northeast-oriented Little Beaver Creek tributary valleys. However, the northwest-southeast orientations of the secondary tributary valleys suggests the figure 10 drainage history is similar to drainage histories determined for previous figures. Flood waters flowed in a south-southeast direction across the entire figure 10 map area and were first captured by headward erosion of the deep northeast-oriented Little Beaver Creek. Headward erosion of the deep east and east-northeast oriented North Beaver Creek valley then beheaded south-southeast oriented flood flow to actively eroding southeast-oriented Little Beaver Creek tributary valleys. Next headward erosion of the deep North Fork Driftwood Creek valley beheaded and reversed south-southeast oriented flood routes in the figure 10 east half. Then headward erosion of the Republican River valley (north of the figure 10 map area) beheaded and reversed flood flow in the figure 10 north center area to create the north-oriented East Fork Burntwood Creek valley. Finally headward erosion of the deep South Fork Republican River valley beheaded and reversed flood to create the north-oriented Jones Canyon and Big Timber Creek valleys in the figure 10 northeast quadrant. Secondary north-northwest oriented tributary valleys were eroded by reversed flow flowing to primary north-oriented Republican River tributary valleys.

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.