Abstract:

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore northwest Nebraska and southwest South Dakota Hat Creek-White River drainage divide area landform origins. 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 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 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 similar essays is a thick North American ice sheet, comparable in thickness to the present day Antarctic ice sheet, occupied approximately the North American region usually recognized to have been glaciated and through its weight and erosive actions created a “deep” North American “hole”, 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 immense melt water 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 northwest Nebraska and southwest South Dakota Hat Creek-White River drainage divide area landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Hat Creek-White River drainage divide area general location map

Hat Creek-White River drainage divide area detailed location map

Figure 2: Hat Creek-White River 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 Hat Creek-White River drainage divide area. Sioux and Dawes Counties are located in Nebraska. Fall River and Shannon Counties are in South Dakota and the red area in Shannon County indicates Pine Ridge Indian Reservation land. Niobrara County to the west is located in Wyoming. Harrison, Nebraska is located in Sioux County at the intersection of US highway 20 and state highway 29. The White River originates just east of Harrison and flows southeast to Andrews and Glen, where it turns northeast to flow through Fort Robinson State Park, Crawford and Dakota Junction and then past Slim Butte, South Dakota to the figure 2 northeast corner. Hat Creek originates a short distance northeast of Harrison and flows north-northeast to Ardmore, South Dakota and then to the Cheyenne River just west of Angostura Reservoir at the Black Hills south end. Horsehead Creek is a northeast and northwest oriented Cheyenne River tributary important to the discussion here and originates east of Ardmore, South Dakota and flows northeast to Oelrichs, South Dakota and then turns northwest to flow to the Cheyenne River at Angostura Reservoir. Detailed maps in this essay begin at the south end of the Hat Creek-White River drainage divide area and proceed northeast along the divide to the Horsehead Creek-White River drainage divide and then proceed northeast along that divide to the Blacktail Creek area before concluding with a look at the Hat Creek-Horsehead Creek drainage divide area. Note the many southeast-oriented tributaries to north- and northeast-oriented White River, Niobrara River, Hat Creek, and Horsehead Creek valley segments and northwest-oriented tributaries flowing to those same valley segments. This southeast-northwest oriented drainage alignment is evidence those major valley segments were eroded headward across multiple southeast-oriented flood flow channels, such as might be found in a large-scale southeast-oriented anastomosing channel complex, and provides evidence for a massive southeast-oriented flood moving across the region.

Southwest end of Hat Creek-White River drainage divide near Harrison, Nebraska

Figure 3: Southwest end of Hat Creek-White River drainage divide near Harrison, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 illustrates the southwest end of the Hat Creek-White River drainage divide area near Harrison, Nebraska. The White River originates just east of Harrison and the railroad follows it in a southeast direction to the figure 3 south edge. Southeast-oriented streams east of the northeast-oriented ridge in the figure 3 northeast corner flow to the northeast-oriented White River (which turns northeast after flowing southeast-see figure 2). The unnamed stream flowing southeast to Harrison and then south to the figure 3 south edge is a Niobrara River tributary and the southeast-oriented Niobrara River is located south of the figure 3 map area. The predominance of southeast-oriented drainage south of the forested north-facing escarpment is evidence southeast-oriented flood flow moved over the southern upland surface to the Niobrara River south and southeast of figure 3 and was in the in the process of being captured by White River valley headward erosion. North-oriented streams flowing from the forested north-facing escarpment slope are Hat Creek tributaries. The escarpment-surrounded basin is an abandoned headcut eroded by immense quantities of southeast-oriented flood waters (originally flowing to what was then the actively eroding Niobrara River valley and which were in the process of being captured by White River valley headward erosion), and which were rapidly captured and diverted north to the much deeper northeast-oriented Cheyenne River at the Black Hills south end. Northwest-oriented Hat Creek tributary valleys were eroded by reversals of flood flow on the northwest ends of beheaded southeast-oriented flood flow routes. Bodarc, South Dakota, which is located on north-oriented Hat Creek is approximately 300 meters lower than Harrison on the upland surface to the south. The height of the north-facing escarpment provides evidence as to the amount of material flood waters removed from the region between the north-facing escarpment and the Black Hills south end, which in turn provides clues as to the magnitude of the flood responsible for the Hat Creek headcut erosion. The source of the flood waters cannot be determined from evidence here. However,  use of many different Missouri River drainage basin landform origins research project essays (published on this website) can be used to trace flood waters headward to a North American ice sheet location. Rapid melting of a thick North American ice sheet located in a deep “hole” would be a logical flood water source and would also explain why deep valleys eroded headward to capture southeast-oriented flood flow and to divert the flood waters further and further to the northeast into space the melting ice sheet had once occupied.

Hat Creek-White River drainage divide in Eagles Eye Rock area

Figure 4: Hat Creek-White River drainage divide in Eagles Eye Rock area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 illustrates the Hat Creek-White River drainage divide area northeast of the figure 3 map area and includes overlap with figure 3. The White River valley southeast of figure 4 is illustrated in the White River-Niobrara River drainage divide essay. Southeast-oriented North and Middle Forks of southeast-oriented Soldier Creek flow to the figure 4 southeast corner and are White River tributaries. Further north are southeast-oriented headwaters of Little Cottonwood Creek and still further north are southeast-oriented headwaters of Sand Creek, which flow to Little Cottonwood Creek and to the northeast-oriented White River. These southeast-oriented tributary valleys eroded headward into what was then the newly eroded and deep northeast-oriented White River valley wall by southeast-oriented flood flow. The southeast-oriented flood flow routes were beheaded by headward erosion of the deep Hat Creek valley to the west. West of the northeast-oriented ridge separating the Hat Creek valley and the White River valley (and also serving as the drainage divide) are northwest-oriented Hat Creek tributaries. Northwest-oriented Hat Creek tributary valleys were eroded by reversals of flood flow on the northwest ends of beheaded southeast-oriented flood flow routes. Reversed flood flow not only eroded northwest-oriented tributary valleys, but also created the present day Hat Creek-White River drainage divide. Note how the high ridge between the two major drainage basin narrows to the northeast and then ceases to exist. Northeast of Roundtop (at the northeast end of the ridge) all evidence of the high level topographic surface into which the deep White River valley was eroded has been completely removed. Prior to being captured by headward erosion of the Cheyenne River-Hat Creek valley southeast-oriented flood flow moving to the newly eroded White River valley eroded large and parallel southeast-oriented valleys headward from what was then the newly eroded northeast-oriented White River valley.

Hat Creek-White River drainage divide in the Orella, Nebraska area

Figure 5: Hat Creek-White River drainage divide in the Orella, Nebraska area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Hat Creek-White River drainage divide area northeast of the figure 4 map area and includes overlap areas with figure 4. The figure 5 map area is located just south of the Nebraska-South Dakota state line. Hat Creek flows northeast and north in the figure 5 northwest quadrant. Whitehead Creek is the northwest-oriented Hat Creek tributary flowing from near Roundtop to join Hat Creek in figure 5 northwest corner. Note how the northeast-oriented ridge that had been separating the north-oriented Hat Creek drainage basin from the northeast-oriented White River drainage basin ends at Roundtop in the figure 5 south center. The lack of any high erosional remnants northeast of Roundtop is evidence southeast-oriented flood flow to what was then the newly eroded and deep northeast-oriented White River valley was intense and removed all evidence of what had been the White River valley northwest wall. The Hat Creek-White River drainage divide was lowered by erosion of a series of large parallel southeast-oriented headcuts or valleys eroded headward from the newly eroded and deep White River valley. The floors of some of those valleys are now drained to the northwest by northwest-oriented Hat Creek tributaries and to the White River (located southeast of figure 5) by southeast-oriented White River tributaries. Note how northwest-oriented Long Branch Creek is aligned with southeast-oriented Big Cottonwood Creek. In some cases through valleys are today drained to adjacent northwest-southeast oriented through valleys. For example, southeast of Orella (figure 5 center) the railroad travels through what might be considered a northwest-southeast oriented through valley (between Roundtop and the Mike Kern Hills), although that valley is drained by east, northeast, and even north-oriented streams to southeast-oriented Big Cottonwood Creek further east. Apparently southeast-oriented flood flow on the Long Branch Creek-Big Cottonwood Creek alignment eroded a deeper southeast-oriented valley on that alignment than existed on through valley further west (and now used by the railroad).

Horsehead Creek-White River drainage divide in the Wayside, Nebraska area

Figure 6: Horsehead Creek-White River drainage divide in the Wayside, Nebraska area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the Hat Creek-White River drainage divide area northeast of the figure 5 map area and includes overlap areas with figure 5. Horsehead Creek seen here does not flow to Hat Creek, but instead flows northeast and northwest to the Cheyenne River (north-oriented Hat Creek is a separate Cheyenne River tributary) and for that reason figures 6, 7 and 8 illustrate the Horsehead Creek (Cheyenne River)-White River drainage divide. The Hat Creek-White River drainage divide is located in the figure 6 southwest corner (southwest of Wolf Butte where Horsehead Creek headwaters begin). The Horsehead Creek-White River drainage divide extends in southwest-northeast direction across figure 6 from just south of Wolf Butte to the figure 6 northeast corner. Southeast of the drainage divide all drainage routes are southeast-oriented and flow to the northeast-oriented White River. Numerous southeast-oriented tributaries flow to northeast-oriented Horsehead Creek. What has happened is the northeast-oriented Horsehead Creek valley eroded southwest across multiple southeast-oriented flood flow routes to capture southeast-oriented flood flow and to divert the flood water northeast (and then northwest) to what was then the newly eroded and deeper northeast-oriented Cheyenne River valley. Note how Horsehead Creek has northwest-oriented tributaries in addition to northeast-oriented tributaries. Northwest oriented tributary valleys (e. g. north of the South Dakota state line) were eroded by reversals of flood flow on northwest ends of beheaded southeast-oriented flood flow routes. Southeast-oriented flood flow to the figure 6 map area was beheaded by headward erosion of the deep Cheyenne River valley and its Hat Creek tributary valley located north and west of the figure 6 map area.

Horsehead Creek-White River drainage divide in the Antelope Hollow area

Figure 7: Horsehead Creek-White River drainage divide in the Antelope Hollow area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 illustrates the Horsehead Creek-White River drainage divide area northeast of the figure 6 map area and includes significant overlap areas with figure 6. Horsehead Creek flows from the figure 7 southwest corner area to the figure 7 north center edge. As Horsehead Creek flows north it gradually changes from being a northeast-oriented stream to becoming a north-oriented stream. The Horsehead Creek-White River drainage divide parallels Horsehead Creek is located along the ridge east of Horsehead Creek. East of the  drainage divide are southeast and east-oriented White River tributaries. These tributary valleys were initiated as southeast and east-oriented flood water eroded southeast and east oriented headcuts or valleys northwest and west into what was then the newly eroded White River valley wall. Readers might want to refer back to figure 2 to better understand White River tributary orientations here. The White River, which flowed northeast from the Crawford, Nebraska area into South Dakota then flows almost straight north for a distance. That north-oriented White River valley segment is located east of the figure 7 map area. While flood waters have probably removed much of the evidence, remnants of headcuts eroded west from what was then the newly eroded White River valley can still be seen. For example, in the figure 7 northeast corner east-oriented headwaters of the South Branch of Blacktail Creek originate in an east-oriented basin (Blacktail Creek is a White River tributary-see figure 2). That east-oriented basin is an abandoned headcut eroded west, prior to headward erosion of the northeast-oriented South Fork Blacktail Creek valley (see unnamed northeast-oriented stream just west of the South Branch Blacktail Creek headwaters area), which beheaded final flood flow routes responsible for the South Branch Blacktail Creek headcut erosion, although figure 8 will illustrate where he water was coming from. Subsequently headward erosion of the Horsehead Creek valley beheaded flood flow routes to the South Fork Blacktail Creek valley and then headward erosion of the Cheyenne River valley and Hat Creek valley beheaded flood flow routes to the Horsehead Creek valley.

Horsehead Creek-White River drainage divide in the Oelrichs, South Dakota area

Figure 8: Horsehead Creek-White River drainage divide in the Oelrichs, South Dakota area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 8 illustrates the Horsehead Creek-White River drainage divide area north of the figure 7 map area and includes overlap areas with figure 7. Horsehead Creek flows north along the highway to Oelrichs and then turns northwest to flow to the east and northeast oriented Cheyenne River as a barbed tributary (see figure 10 below). Note how the northwest oriented Horsehead Creek valley alignment points directly at the previously discussed South Branch Blacktail Creek headcut located in the figure 8 southeast quadrant. Apparently a major southeast oriented flood flow route moving along the present day northwest oriented Horsehead Creek alignment was responsible for eroding the South Branch Blacktail Creek headcut west (and also the Blacktail Creek valley with its various tributaries including its South Fork). That southeast-oriented flood flow route was then beheaded by headward of the deep Cheyenne River valley causing a reversal of flood flow on the northwest end of the beheaded flood flow route so the reversed flood waters flowed northwest to the newly eroded and deeper east and northeast-oriented Cheyenne River valley. Reversed flood flow on what is today the northwest-oriented Horsehead Creek valley segment then captured yet to be beheaded southeast-oriented flood flow further to the south and southwest. Those captured flood waters eroded the northeast- and north-oriented Horsehead Creek valley seen in figures 6 and 7 and south of Oelrichs in figure 8. Subsequently headward erosion of the deep Cheyenne River valley and its north-oriented Hat Creek tributary valley beheaded all southeast-oriented flood flow routes to the newly eroded Horsehead Creek valley.

Hat Creek Creek-Horsehead Creek drainage divide in the Ardmore, South Dakota area

Figure 9: Hat Creek Creek-Horsehead Creek drainage divide in the Ardmore, South Dakota area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the Hat Creek-Horsehead Creek drainage divide area north of figure 5 and west of figure 6 and includes overlap areas with figures 5 and 6. Northeast-oriented Horsehead Creek is located in the figure 9 southeast corner. North-northeast oriented Hat Creek flows from the figure 9 southwest corner to the figure 9 northwest quadrant. Note how the Hat Creek-Horesehead Creek drainage divide area has been streamlined in a northwest-southeast direction. Hat Creek tributaries are almost all northwest-oriented and Horsehead Creek tributaries are almost all southeast-oriented. Northwest-southeast oriented through valleys link the northwest-oriented tributary valleys with southeast-oriented tributary valleys. The northwest-southeast oriented drainage alignment, the northwest-southeast oriented through valleys, and the northwest-southeast oriented landscape streamlining are all evidence large quantities of southeast-oriented flood water once flowed across the present day Hat Creek-Horsehead Creek drainage divide to what must have been the newly eroded Horsehead Creek valley. Subsequently headward erosion of the Hat Creek valley beheaded the southeast-oriented flood flow routes and caused reversals of flood flow on the northwest ends of the beheaded flood flow routes. Those reversals of flood flow were responsible for eroding the northwest-oriented tributary valleys and also for creating what is today the Hat Creek-Horsehead Creek drainage divide.

Hat Creek Creek-Horsehead Creek drainage divide south of Cheyenne River

Figure 10: Hat Creek Creek-Horsehead Creek drainage divide south of Cheyenne River. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 10 illustrates the Hat Creek-Horsehead Creek drainage divide area north and west of the figure 8 map area and includes overlap areas with figure 8. Hat Creek flows north along the figure 10 west edge to join the meandering Cheyenne River in the figure 10 northwest corner. Horsehead Creek flows northwest from the figure 10 east edge center to join the north and northeast-oriented Cheyenne River valley at Angostura Reservoir. Jackson Narrows at the Angostura Reservoir west end provides an explanation as to why the Horsehead Creek valley developed the way it did. Apparently rocks in the Jackson Narrows area are more resistant to erosion than rocks that once existed in the present day lowland areas to the east and south (Jackson Narrows is located at the south end of the Black Hills uplift). The deep Cheyenne River valley when it eroded southwest and west must have eroded into a topographic surface at least as high as the present day depth of the Jackson Narrows canyon (approximately 160 meters), otherwise the Cheyenne River valley would not be located where it is. In other words, the regional topographic surface into which the Cheyenne River valley was eroded was significantly higher than regional surface is today and flood waters moved southeast on that higher level surface to what was then the newly eroded and deep northeast-oriented White River valley. Apparently southeast-oriented flood flow moving near from the present day Angostura Reservoir area was eroding east-oriented headcuts (now headwaters of Blacktail Creek tributaries) and was beheaded as the deep Cheyenne River valley eroded southwest and south. Reversed flood flow on the northwest ends of those beheaded flood flow routes then eroded what must have been a deep northwest-oriented Horsehead Creek valley headward and then south and southwest to capture yet to be beheaded southeast-oriented flood flow routes further to the south and southwest. Because the deep Cheyenne River valley had to erode through more resistant rocks than the Horsehead Creek valley there was sufficient time for the Horsehead Creek valley to capture significant southeast-oriented flood flow. However, once the Cheyenne River valley broke through the resistant rock (i.e. carved the Jackson Narrows canyon) the north-oriented Hat Creek valley rapidly eroded south and beheaded all southeast-oriented flood flow routes to the Horsehead Creek valley.

Additional information and sources of maps studied

This essay has provided only a sample of the detailed topographic map evidence supporting the flood erosion interpretation. Many additional illustrations could be provided. Readers are encouraged to look at mosaics of detailed topographic maps to see the abundance of available data. Maps used in this study were created and published by the United States Geologic Survey and can be obtained directly from the United States Geological Survey and/or from dealers offering United States Geological Survey maps. Hard copy maps can also be observed at United States Geological Survey map depositories which are located throughout the United States and elsewhere. Illustrations used here were created using National Geographic Society TOPO software and digital map data. TOPO software and map data can be obtained from the National Geographic Society and/or dealers offering National Geographic Society digital map data.