Abstract:

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore northwest Nebraska White River-Niobrara 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 White River-Niobrara River drainage divide area landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

White River-Niobrara River drainage divide area general location map

Figure 1: White River-Niobrara River drainage divide area general 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 general location map for the northwest Nebraska White River-Niobrara River drainage divide area. South Dakota is the state north of Nebraska and Wyoming is west of Nebraska. The White River begins near Harrison (in the extreme northwest corner of Nebraska) and flows southeast, then turns northeast to flow into South Dakota and eventually to reach the southeast-oriented Missouri River (located east of the figure 1 map area). The Niobrara River originates near Lusk, Wyoming (west of Harrison, Nebraska) and flows southeast before turning northeast and also eventually reaching the southeast-oriented Missouri River. The White River-Niobrara River drainage divide area considered by this essay represents the drainage divide area west of Gordon, Nebraska. The  White River-Little White River drainage divide area essay and the Little White River-Niobrara River drainage divide essay address the drainage divide areas between Gordon, Nebraska and Valentine, Nebraska and the Keya Paha River-Niobrara River drainage divide area essay and the White River-Keya Paha River drainage divide area essays address White River-Niobrara River drainage divide area east of Valentine, Nebraska. These essays can be found under White River on the sidebar category list. Note how the White River and the Niobrara River both originate in the same general region, both initially flow southeast, and then diverge only to eventually flow to the same southeast-oriented Missouri River. This evidence is interpreted to mean the White River and Niobrara River valleys were eroded headward to capture what was an immense southeast-oriented flood that flowed over most or all of the figure 1 map area, probably eroding what was then a large-scale southeast-oriented anastomosing channel complex. Headward erosion of the Niobrara River valley first captured the southeast-oriented flood waters and diverted the flood flow northeast and east of the figure 1 map area. Subsequently a much deeper White River valley eroded west and southwest to capture southeast-oriented flood flow to what was then the newly eroded Niobrara River valley and to divert the flood waters further to the north and east. Headward erosion of both valleys at times proceeded northwest along the alignments of captured southeast-oriented flood flow channels, with present day southeast-oriented Niobrara River and White River valley segments, including the headwaters areas of both rivers being evidence of such erosion northwest along captured flood flow routes.

White River-Niobrara River drainage divide area detailed location map

Figure 2: White River-Niobrara 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 White River-Niobrara River drainage divide area addressed here. Sioux, Dawes, and Sheridan Counties are located in Nebraska and Fall River County is located in South Dakota. The red area east of Fall River County is the Pine Ridge Indian Reservation and is also Shannon County, South Dakota. The Niobrara River flows southeast from the figure 2 west edge (by the highway) to the Agate Fossil Beds National Monument and then turns east to flow into Sheridan County where it turns north to flow to the figure 2 east edge. The White River originates near Harrison, Nebraska (just east of the figure 2 west edge where the Niobrara River enters the figure 2 map area) and flows southeast to Glen, Nebraska and then turns northeast to flow through Fort Robinson State Park and Crawford, Nebraska and then into the South Dakota Pine Ridge Indian Reservation. Note the area labeled Pine Ridge between the two rivers in Dawes County. Pine Ridge as seen in detailed maps below is both a ridge and northwest-face escarpment because the White River valley is much deeper than the Niobrara River valley to the south and southeast. Note also the southeast-oriented tributaries to the east and northeast-oriented Niobrara River and northwest-oriented tributaries to the northeast-oriented White River. The southeast-northwest tributary alignment is evidence both the Niobrara River valley and the White River valley eroded headward across what had been multiple southeast-oriented flood flow channels or routes. Headward erosion of the Niobrara River valley captured the southeast-oriented flood flow first and subsequently headward erosion of the much deeper White River valley beheaded southeast-oriented flood flow routes to the newly eroded Niobrara River valley. Flood waters on the northwest ends of the beheaded flood flow routes then reversed flow direction to flow northwest into the much deeper and newly eroded White River valley. These reversals of flood flow on the northwest ends of beheaded flood flow routes were responsible for eroding what are today northwest-oriented White River tributary valleys and also for creating what is today the White River-Niobrara River drainage divide.

West end of the White River-Niobrara River drainage divide area near Harrison, Nebraska

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

Figure 3 illustrates the west end of the White River-Niobrara River drainage divide area. The Niobrara River flows from the figure 3 west center edge to the figure 3 southwest corner. The White River originates a short distance east of Harrison, Nebraska and flows southeast to the figure 3 east center edge. Southeast-oriented drainage in the figure 3 northwest corner flows to Harrison and then south and southwest to join the southeast oriented Niobrara River. Note the multiple southeast oriented tributaries to the unnamed south-oriented Niobrara River tributary. Had White River valley headward erosion progressed further to the northwest the White River valley would have captured the southeast oriented headwaters of the previously mentioned south-oriented Niobrara River tributary and the White River-Niobrara River drainage divide area would have been extended further to the west and northwest. For reasons that cannot be determined with figure 3 evidence flood flow to the figure 3 map area was captured further to the northwest and headward erosion of the White River valley and its various tributary valleys ceased. Also note southeast-oriented White River tributaries located between the highway and the White River, and southeast-oriented headwaters of Soldier Creek in the Nebraska National Forest located in the figure 3 northeast corner. These southeast-oriented tributaries and the White River and Soldier Creek southeast-orientations are evidence of original southeast-oriented flood flow routes across the region. Further note southeast- and northwest-oriented tributaries and valley segments associated with the north-oriented White River tributaries. For example Kyle Creek has southeast-oriented tributaries indicating the Kyle Creek valley eroded south to capture southeast-oriented flood flow not yet beheaded by headward erosion of the south-oriented Niobrara River tributary valley at Harrison. A northwest-oriented Kyle Creek valley segment developed as a reversal of flood flow on the northwest end of a beheaded southeast-oriented flood flow route. See figure 4 below to see where southeast-oriented flood flow Kyle Creek valley headward erosion captured had been going (Barngrover Creek valley discussion). Several north-oriented White River tributaries east of Kyle Creek, including Bull Creek, also have northwest-oriented headwaters, providing evidence of flow reversals on beheaded flood flow routes.

White River-Niobrara River drainage divide area south of Crawford, Nebraska

Figure 4: White River-Niobrara River drainage divide area south of Crawford, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 illustrates the region east and south of the figure 3 map area and provides an overlap area. The White River elbow of capture at Glen, Nebraska can just be seen in the figure 4 northwest corner (see figure 5 for a more complete view). Headward erosion of the deep northeast-oriented White River valley captured a major southeast-oriented flood flow route in the Glen, Nebraska location and then eroded headward along that southeast-oriented flood flow route. Note how the White River valley has deepened from its origin area near Harrison. At Glen the valley is more than 200 meters below the Pine Ridge Escarpment rim to the south. The northeast-oriented Niobrara River is located in the figure 4 southeast corner. Niobrara River tributaries in the figure 4 map area are almost all southeast-oriented, indicating the Niobrara River valley eroded headward to capture multiple southeast-oriented flood flow routes. The southeast-oriented Barngrover Creek valley eroded headward from what was then the actively eroding Niobrara River valley to capture southeast-oriented flood flow routes, although headward erosion of the Barngrover Creek valley ceased when headward erosion of the deeper White River valley and its north-oriented Kyle Creek tributary valley beheaded flood flow routes that had been eroding the Barngrover Creek valley (see figure 3 to see how Kyle Creek valley headward erosion captured the southeast-oriented flood flow to the actively eroding Barngrover Creek valley). Nearly all White River tributaries are northwest-oriented indicating they were eroded by reversals of flood flow on the northwest ends of southeast-oriented flood flow routes beheaded by headward erosion of the deep White River valley. Flood flow reversed flow direction to flow northwest into the newly eroded and much deeper White River valley and in the process eroded what are today northwest-oriented White River tributary valleys and also created the White River-Niobrara River drainage divide. A close look at the drainage divide shows shallow through valleys link headwaters of the northwest-oriented White River tributaries with headwaters of the southeast-oriented Niobrara River tributaries. Those through valleys are evidence southeast-oriented flood flow moved in multiple channels, characteristic of an anastomosing channel complex, across what is now the White River-Niobrara River drainage divide prior to erosion of the deep White River valley.

White River valley near Crawford, Nebraska

Figure 5: White River valley near Crawford, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the White River area north of the figure 4 map area and includes overlap areas with figure 4. The White River elbow of capture at Glen, Nebraska is better illustrated here where the southeast-oriented White River valley to the west turns to become a northeast-oriented valley. Southeast-oriented Soldier Creek tributaries northwest of the Fort Robinson State Wildlife Area and other southeast-oriented White River tributaries provide evidence the deep northeast-oriented White River valley eroded southwest to capture multiple southeast-oriented flood flow routes. Northwest-oriented White River tributaries from the southeast are evidence flood waters on the northwest ends of beheaded southeast-oriented flood flow routes reversed flow direction to flow northwest into the newly eroded and much deeper northeast-oriented White River valley. Note how the deep White River valley northwest wall is missing in the figure 5 northeast quadrant. Apparently southeast-oriented flood flow into what was then a deep White River valley was of sufficient magnitude it significantly lowered the topographic surface north and west of the newly eroded White River valley, so today the Pine Ridge Escarpment, which was originally eroded as the White River valley southeast and south valley wall has no opposing wall and appears to be a step from a lower topographic surface (or erosion surface) in the north to a higher topographic surface (or erosion surface) in the south. However, prior to headward erosion of the deep White River valley no such step existed and the topographic surface to the north and west was at least as high, if not higher, than the topographic surface to the south and large quantities of flood waters flowed from the northwest across what is today the White River-Niobrara River drainage divide.

White River-Niobrara River drainage divide area south of Chadron, Nebraska

Figure 6: White River-Niobrara River drainage divide area south of Chadron, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the White River-Niobrara River drainage divide region east of figure 4 and south of Chadron, Nebraska and includes overlap areas with figure 4. The Pine Ridge crest is approximately 300 meters higher than the White River valley floor (northwest of the figure 6 map area) and about 150 meters higher than the Niobrara River valley floor (southeast of figure 6). Southeast-oriented drainage from the Pine Ridge crest is flowing to the northeast-oriented Niobrara River and is evidence a deep (at least 150 meters deep) northeast-oriented Niobrara River valley eroded headward into the region to capture multiple southeast-oriented flood flow routes. Most likely the flood waters were flowing in a large southeast-oriented anastomosing channel complex and at least some of the southeast-oriented tributaries may be relics of channels in that anastomosing channel complex. Southeast-oriented flood flow routes to the newly eroded Niobrara River valley were subsequently beheaded by headward erosion of the much deeper northeast-oriented White River valley. The time span between headward erosion of the Niobrara River and White River valleys probably was not long, otherwise southeast-oriented flood flow would have eroded deeper and longer southeast-oriented tributary valleys into what was then the newly eroded Niobrara River northwest valley wall. Flood waters on the northwest ends of the beheaded southeast-oriented flood flow routes reversed flow direction to erode northwest-oriented White River tributary valleys and to create the White River-Niobrara River drainage divide.

Niobrara River valley south of Chadron, Nebraska

Figure 7: Niobrara River valley south of Chadron, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the Niobrara River valley south of the figure 6 map area and includes overlap areas with figure 6. Southeast-oriented Niobrara River tributaries and the relatively smooth southeast-sloping erosion surface are evidence the northeast-oriented Niobrara River valley was eroded headward across multiple southeast-oriented flood flow routes. The Niobrara River valley floor in this location is approximately 150 meters lower than the Pine Ridge crest to the northwest. This means the Niobrara River valley when it was eroded headward into the region was at least 150 meters deep. As noted previously the White River valley floor to the northwest is approximately 300 meters lower than corresponding points on the Pine Ridge crest, which means the northeast-oriented White River valley was at least 300 meters deep when it eroded headward into the region. The Niobrara River valley depth of at least 150 meters and the White River valley depth of at least 300 meters provides some clues as to magnitude of flood flow involved. Evidence presented here is not adequate to determine the flood water source or why headward erosion deep valleys was progressively capturing southeast-oriented flood water and diverting the flood water further and further to the northeast. However, using evidence from numerous Missouri River drainage basin landform origins research project essays published on this website it is possible 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 both explain the flood water source and also why headward erosion of deep valleys was progressively capturing the southeast-oriented flood water and diverting the flood flow further and further to the northeast into space the rapidly melting North American ice sheet had once occupied.

White River-Niobrara River drainage divide area near Hay Springs, Nebraska

Figure 8: White River-Niobrara River drainage divide area near Hay Springs, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 8 illustrates the White River-Niobrara River drainage divide region east of the figure 6 map area and includes overlap areas with figure 6. Chadron, Nebraska is located to the northwest of figure 8. Northwest-oriented drainage from Pine Ridge flows to the northeast-oriented White River, located northwest of Chadron, Nebraska. Southeast-oriented drainage from Pine Ridge flows to the northeast-oriented Niobrara River located southeast of the figure 8 map area. Note the through valley where the highway crosses Pine Ridge. Little Bordeaux Creek flows northwest and has its headwaters southeast of the Pine Ridge crest. In other words, Little Bordeaux is flowing through a water gap cut across the Pine Ridge crest. Note how Little Bordeaux Creek headwaters include a southwest-oriented tributary and an east and northeast-oriented tributary. Those tributaries provide additional clues as to how the northwest-oriented White River tributary valleys were eroded. An unnamed northwest-oriented stream (named Beaver Creek north of figure 8) flows to the figure 8 north center edge (just north of the word PINE). Note how Beaver Creek headwaters are linked by a through valley with the previously mentioned southwest-oriented Little Bordeaux Creek tributary. Also note northwest-oriented Bordeaux Creek flowing to the figure 8 northwest corner and how a northwest-oriented Bordeaux Creek tributary headwaters are linked with the previously mentioned east and northeast-oriented Little Bordeaux Creek tributary. What has happened here is the deep northeast-oriented White River valley eroded headward into the region and beheaded southeast-oriented flood flow on the Beaver Creek alignment first. Reversed flow on the northwest end of that beheaded flood flow route captured yet to be beheaded southeast-oriented flood flow on the Little Bordeaux Creek alignment and eroded a southwest-northeast oriented through valley. Subsequently headward erosion of the White River valley beheaded southeast-oriented flood flow using the Little Bordeaux Creek alignment and reversed flow on that alignment captured yet to be beheaded flood flow on the Bordeaux Creek alignment. This process was repeated over and over again and accounts for the volumes of flood water needed to erode northwest-oriented White River tributary valleys.

White River-Niobrara River drainage divide area near Rushville, Nebraska

Figure 9: White River-Niobrara River drainage divide area near Rushville, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the White River-Niobrara River drainage divide east and north of the figure 8 map area and includes overlap areas with figure 8. North-oriented White Clay Creek is located in the figure 9 northwest corner and continues to flow north and then northwest to join the northeast-oriented White River as a barbed tributary (north of the figure 9 map area). The northwest-oriented highway follows the valley of an unnamed northwest-oriented White Clay Creek tributary. Headwaters of northwest-oriented Larrabee Creek are located along the figure 9 north edge between the highway and the figure 9 northeast corner. Southeast-oriented drainage in the Rushville area flows to southeast-oriented Rush Creek and then to the northeast-oriented Niobrara River, located southeast of the figure 9 map area. East-oriented drainage in the Clinton area flows to northeast and southeast-oriented Antelope Creek, which also flows to the northeast-oriented Niobrara River. Southeast-oriented drainage in the figure 9 northeast corner flows to southeast-oriented Antelope Creek (and is closely aligned with northwest-oriented Larrabee Creek headwaters). The north-south ridge north of the highway between Rushville and Clinton separates what were once two major south and southeast-oriented flood flow routes. The Antelope Creek flood flow route to the east is better illustrated in figure 10 below. The White Clay Creek-Rush Creek flood flow route is best observed in figure 9. A large south-southeast oriented escarpment-surrounded basin or headcut was eroded north-northwest from what was then the newly eroded Niobrara River valley northwest wall along what is today the White Clay Creek-Rush Creek alignment. Headward erosion of the deep White River valley to the north then beheaded southeast-oriented flood flow to the actively eroding south-southeast oriented headcut and flood waters on the northwest and north ends of flood flow routes to the actively eroding headcut reversed flow direction to erode the north and northwest-oriented White Clay Creek valley and to create the White Clay Creek-Rush Creek drainage divide. Today the abandoned headcut serves as the southeast-oriented Rush Creek drainage basin.

East end of White River-Niobrara River drainage divide area near Gordon, Nebraska

Figure 10: East end of White River-Niobrara River drainage divide area near Gordon, Nebraska. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 10 illustrates the east end of the White River-Niobrara River drainage divide region discussed here and is located east and north of the figure 9 map area and includes overlap areas with figure 9. Northwest-oriented Larrabee Creek is located along the figure 10 west edge (north half). Northeast-oriented headwaters of north-northwest oriented Wounded Knee Creek are located along the figure 10 north edge east of the Larrabee Creek drainage basin. The north-south ridge separating the Rush Creek drainage basin to west from the Antelope Creek drainage to east and north is located in figure 10 southwest corner. Antelope Creek flows northeast from the figure 10 south center to northwest of Gordon, Nebraska and then turns southeast to flow through Gordon to the figure 10 southeast corner and then to the northeast-oriented Niobrara River (located southeast of figure 10).  Multiple southeast-oriented tributaries flow to the northeast-oriented Antelope Creek valley segment and also parallel the southeast-oriented Antelope Creek valley segment (and some flow directly to the Niobrara River). A northwest-southeast oriented through valley links the north-northwest oriented Wounded Knee Creek drainage basin with the southeast-oriented Antelope Creek drainage basin. Southeast-oriented flood flow moving along what is today the Wounded Knee Creek-Antelope Creek alignment eroded a large southeast-oriented valley or headcut northwest from what was then the newly eroded Niobrara River northwest valley wall. Headward erosion of the deep White River valley to the northwest then beheaded flood flow responsible for eroding that southeast-oriented headcut. Flood waters on the northwest ends of the beheaded flood flow routes then reversed direction to erode the north-northwest oriented Wounded Knee Creek drainage basin and also to create the Wounded Knee Creek-Antelope Creek drainage divide.

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.