A geomorphic history based on topographic map evidence

The Bow Creek-Logan Creek and other drainage divides in Cedar, Dixon, and Dakota Counties are located in northeast Nebraska between the southeast oriented Missouri River and the southeast oriented Elkhorn River. Bow Creek is a northeast and north oriented Missouri River tributary and Logan Creek is a southeast and south oriented Elkhorn River tributary. The Elkhorn River eventually flows to the Platte River, which flows to the Missouri River. Drainage divides in the Cedar, Dixon, and Dakota County area are interpreted to have originated during an immense southeast-oriented flood, which flowed across the entire northeast Nebraska region. Headward erosion of the deep Missouri River valley and its tributary valleys systematically captured the flood waters, with the Platte River-Elkhorn River and their tributary valleys eroding headward into the region first. Subsequently the deeper Missouri River valley eroded headward and beheaded southeast-oriented flood flow routes to the newly eroded Elkhorn River valley and tributary valleys. Evidence supporting this interpretation includes the presence of through valleys across present day drainage divides, orientations of tributary valleys, barbed tributaries, and elbows of capture.

Preface:

• The purpose of this essay is to use topographic map interpretation methods to explore Bow Creek-Logan Creek and other drainage divides landform origins in Cedar, Dakota, and Dixon Counties, Nebraska, 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 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 Bow Creek-Logan Creek and other drainage divides landform origins evidence in Cedar, Dixon, and Dakota Counties, Nebraska 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.

Cedar, Dixon, and Dakota County area, Nebraska location map

Figure 1: Cedar, Dixon, and Dakota County area, Nebraska 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 location map for the Cedar, Dixon, and Dakota County area in northeast Nebraska. Nebraska is the state located in the figure 1 southwest area and South Dakota is north of Nebraska. East of Nebraska is Iowa and north of Iowa is Minnesota. The major river in figure 1 is the Missouri River, which flows from the figure 1 northwest corner area to the South Dakota-Nebraska border and forms the South Dakota-Nebraska border from Fort Randall Dam to Sioux City, Iowa. South of Sioux City, Iowa the Missouri River is the Nebraska-Iowa border. South-oriented Missouri River tributaries in South Dakota include the south and southeast oriented James River, which joins the Missouri River near Yankton, South Dakota, and the south-oriented Big Sioux River, which flows along the South Dakota-Iowa border and joins the Missouri River near Sioux City. Essays found under James River and Big Sioux River on the sidebar category list include detailed illustrations and discussions related to landform evidence in those drainage basins. Major figure 1 rivers include the Niobrara River (located in the figure 1 west center and flowing to the Missouri River at Niobrara, Nebraska) and the Elkhorn River (flowing from Stuart to O’Neill, Neligh, Norfolk, Pilger, and Scribner before reaching the figure 1 south edge. Essays found under Niobrara River and Elkhorn River on the sidebar category list illustrate and describe landform evidence in those drainage basins. The Cedar, Dixon, and Dakota County area illustrated and discussed in this essay is located east of north-south highway 81 (extending from Yankton, South Dakota to Norfolk, Nebraska), south and west of the Missouri River,  and north of Wayne, Nebraska. Bow Creek on figure 1 is the unlabeled northeast and north oriented Missouri River tributary flowing through Hartington and Wynot. Logan Creek is the unlabeled southeast and south oriented stream flowing from Laurel to Wakefield, Pender, Bancroft, and Lyons, and which joins the Elkhorn River near Hooper (north of Fremont in the figure 1 south center area). Missouri River drainage basin landform origins research project essays published on this website for South Dakota drainage basins establish a strong case for the presence of a rapidly melting ice sheet margin in South Dakota, just east and north of the present day Missouri River valley. Those essays have also built a case for headward erosion of the deep Missouri River valley to capture immense southeast oriented ice marginal melt water floods and also south-oriented floods from ice-walled and bedrock-floored valleys sliced into the decaying ice sheet surface. Prior to headward erosion of the Missouri River valley those southeast and south oriented flood waters flowed across northeast Nebraska and were captured by headward erosion of the Elkhorn River valley and its tributary valleys. Headward erosion of the Missouri River valley beheaded flood flow routes to the newly eroded Elkhorn River valley and reversed flood flow directions to create north-oriented Missouri River tributaries.

Cedar, Dixon, and Dakota County area, Nebraska detailed location map

Figure 2: Cedar, Dixon, and Dakota County area, Nebraska detailed location map. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 2 provides a slightly more detailed location map for the Cedar, Dixon, and Dakota County area in northeast Nebraska. The Missouri River is the large southeast oriented river extending from the figure 2 northwest quadrant to the figure 2 southeast quadrant. Northwest of Sioux City the Missouri River is the South Dakota-Nebraska border, with South Dakota north of the river and Nebraska south of the river. South of Sioux City the Missouri River is the Nebraska-Iowa border, with Iowa east of the Missouri River and Nebraska west of the Missouri River. Knox, Cedar, Dixon, Dakota, Pierce, Wayne, and Thurston are Nebraska county names and the county boundaries are shown. Plymouth, Woodbury, and Monona are Iowa county names and Clay and Union are South Dakota county names. Drainage divides of interest in this essay are located primarily in Cedar, Dixon, and Dakota Counties, Nebraska and are located between the southeast oriented Missouri River and southeast oriented Elkhorn River. The Elkhorn River flows along the figure 2 south edge (west end) to Norfolk (located near the south edge) and then southeast. The North Fork Elkhorn River flows south-southwest and south-southeast in eastern Pierce County to join the Elkhorn River at Norfolk. Streams of interest in this essay include northeast oriented Beaver Creek and north-northeast Antelope Creek, which flow to the Missouri River just south of Yankton, South Dakota. Further east is northeast and north oriented Bow Creek, including its tributaries West Bow Creek, Pearl Creek, and East Bow Creek in Cedar County. Logan Creek originates in southeast Cedar County and flows through Laurel into southwest Dixon County.  Further north in Dixon County is southeast- and northeast-oriented South Creek. And beginning in Dixon County and extending into Dakota County is Elk Creek. East of Elk Creek in Dakota County is north-oriented Omaha Creek/ Other streams and tributaries of interest are not labeled on figure 2 and are introduced as they appear on detailed maps below. Present day drainage routes in Cedar, Dixon, and Dakota Counties are interpreted here to have originated during an immense southeast-oriented flood, which moved across the entire figure 2 map region and were probably mostly formed as flood waters were moving to what was then the newly eroded southeast-oriented Elkhorn River valley. Headward erosion of the Logan Creek valley next captured some of the southeast-oriented flood flow. Headward erosion of the deep Missouri River valley then captured the southeast-oriented flood flow and in the process beheaded the southeast-oriented flood flow routes. Flood waters on the north-ends of the beheaded flood flow routes reversed flow direction to flow in a north-direction to the newly eroded and deeper Missouri River valley as barbed tributaries.

Antelope Creek-West Bow Creek drainage divide area

Figure 3: Antelope Creek-West Bow Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 illustrates the Antelope Creek-West Bow Creek drainage area in northern Nebraska and south of Yankton, South Dakota. The Missouri River, which forms the South Dakota-Nebraska border, flows east along the figure 3 north edge (west half) and then turns to flow in a southeast direction to the figure 3 east center edge. West Bow Creek is the northeast-oriented stream in the figure 3 southeast quadrant flowing to join the Missouri River just east of the figure 3 east edge. Second Bow Creek is the east-oriented West Bow Creek tributary in the figure 3 southeast quadrant. Note how Second Bow Creek has a major southeast-oriented tributary. Beaver Creek is the northeast-oriented Missouri River tributary west of highway 81 in the figure 3 northwest quadrant and Antelope Creek is the north-oriented stream east of highway 81. Note northwest-oriented (barbed) tributaries to the east-oriented Missouri River in the figure 3 north center. Also note northwest-oriented and southeast-oriented tributaries to Beaver Creek, Antelope Creek, Second Bow Creek, and West Bow Creek. A close look at figure 3 reveals numerous northwest-southeast oriented through valleys across drainage divides between the various figure 3 drainage basins. Perhaps the largest and most obvious of these through valleys is located north of Bow Valley (town name located along the figure 3 south edge) and links the east-oriented Second Bow Creek valley with the northeast-oriented West Bow Creek valley. Other through valleys are somewhat more subtle, but can be seen crossing all of the major drainage divides. The northwest-southeast tributary orientation and the northwest-southeast-oriented through valleys are evidence the West Bow Creek, Second Bow Creek, Antelope Creek, and Beaver Creek valleys eroded headward to capture multiple southeast-oriented flood flow channels such as might be found in a large southeast-oriented anastomosing channel complex. The major trunk stream valleys eroded headward into the figure 3 region in sequence as the deep Missouri River valley eroded headward into the region. The West Bow Creek valley first eroded headward from the actively eroding Missouri River valley head to capture yet to be beheaded southeast-oriented flood flow and to divert the flood waters northeast into the newly eroded and deeper southeast-oriented Missouri River valley. The Second Bow Creek valley next eroded west from the newly eroded West Bow Creek valley to capture the southeast-oriented flood flow and to divert the water more directly to the Missouri River valley. Headward erosion of the deep Missouri River valley next permitted the Antelope Creek valley to erode headward to capture the southeast-oriented flood flow and then the northeast-oriented Beaver Creek valley to do the same. Northwest-oriented tributary valleys were eroded by reversals of flood flow on the northwest ends of beheaded flood flow routes.

West Bow Creek-Bow Creek drainage divide area

Figure 4: West Bow Creek-Bow Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 illustrates the West Bow Creek-Bow Creek drainage divide area southeast of the figure 3 map area and includes overlap areas with figure 3. The southwest edge of the southeast-oriented Missouri River valley can just barely be seen in the figure 4 northeast corner. West Bow Creek is the northeast-oriented stream in the figure 4 northwest quadrant. Hartington is the town in the figure 4 southwest quadrant and Bow Creek flows in a northeast and north direction from the Hartington area to the figure 4 north center edge. Dead Creek is the northwest oriented Bow Creek tributary located in the figure 4 west half and East Bow Creek is the northwest oriented Bow Creek tributary located in the figure 4 east half. Norwegian Bow Creek is the southeast-oriented Bow Creek tributary joining Bow Creek near Hartington. Note the presence of other unnamed and shorter northwest and southeast oriented Bow Creek and West Bow Creek tributaries. These northwest and southeast oriented tributaries provide evidence the Bow Creek valley and subsequently the West Bow Creek valley eroded headward across multiple southeast-oriented flood flow channels such as might be found in an anastomosing southeast-oriented channel complex. Further evidence supporting this interpretation is found in the presence of northwest-southeast oriented through valleys linking the West Bow Creek and Bow Creek valleys. The most obvious and largest such through valley is located southwest of the town of Bow Valley (located in the figure 4 northwest quadrant) and extends in a southeast direction from the West Bow Creek valley to the Bow Creek valley. Note how this northwest-southeast oriented through is on approximately the same alignment as the northwest-southeast oriented through valley linking the Second Bow Creek valley with the West Bow Creek valley (seen in figure 3 immediately northwest of the town of Bow Valley). This figure 4 northwest-southeast oriented through valley provides evidence water once flowed from the present day Second Bow Creek drainage basin across the present day West Bow Creek valley to the northeast-oriented Bow Creek valley. Further, note how this through valley alignment is located slightly to the southwest of the northwest-oriented East Bow Creek valley. This similarity in alignments suggests southeast-oriented flood water once continued southeast on an alignment just southwest of the present day northwest-oriented East Bow Creek alignment, although moving across a topographic surface as high or higher than the present day figure 4 drainage divide elevations. Headward erosion of the deep Missouri River valley enabled the deep Bow Creek valley to erode headward into the figure 4 map area to behead southeast-oriented flood flow. Flood waters on the northwest end of the beheaded East Bow Creek flood flow route reversed flow direction to flow northwest to the newly eroded and deep north-oriented Bow Creek valley. The reversed flood flow (probably with the aid of captured yet to be beheaded flood water from further to the southwest) eroded the deep East Bow Creek valley headward along an alignment slightly to the northeast of the beheaded southeast-oriented flood flow channel. This process was then repeated again as the deep West Bow Creek valley eroded headward and then again as the deep Second Bow Creek valley eroded headward.

Kerloo Creek-Perrin Creek drainage divide area

Figure 5: Kerloo Creek-Perrin Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Kerloo Creek-Perrin Creek drainage divide area located south of the figure 4 map area and there is overlap with the figure 4 map area. Bow Creek flows east and then north in the figure 5 northwest quadrant (Hartington is located just north of the figure 5 north edge-note Hartington airport on both figures 4 and 5). Pearl Creek is the northeast and north-northeast oriented tributary located in the figure 5 west center area. Coleridge is the town located in the figure 5 south center area and Kerloo Creek is the northwest-oriented Pearl Creek tributary located immediately northwest of Coleridge. Coleridge is located in a northwest-southeast oriented through valley and southeast of Coleridge the through valley is drained by southeast oriented Perrin Creek, which flows to southeast and south oriented Logan Creek. Dead Creek flows north in the figure 5 north center area and the northwest-oriented stream in the figure 5 northeast corner is East Bow Creek. North Logan Creek is the southeast oriented stream located east of Coleridge flowing to the figure 5 east edge. Southeast of the figure 5 map area North Logan Creek joins southeast and south oriented Logan Creek (see figure 9), which eventually flows to the Elkhorn River. Note how the southeast-oriented North Logan Creek headwaters are linked across what appears to be a flood eroded erosion surface with headwaters of northwest-oriented Bow Creek tributaries and northwest-oriented Dead Creek headwaters. Other somewhat more subtle northwest-southeast oriented through valleys can be seen in the figure 5 southwest quadrant linking the Pearl Creek valley with unnamed southeast-oriented Logan Creek tributary valleys. This evidence along with evidence provided by the northwest-southeast oriented Kerloo Creek-Perrin Creek through valley strongly suggests the figure 5 map region was eroded by a large-scale southeast-oriented flood prior to headward erosion of the present day Bow Creek valley and tributary valleys. Flood waters were moving to what was then the actively eroding Logan Creek valley and were beheaded by headward erosion of the deep north- and northeast-oriented Bow Creek-Pearl Creek valley. Flood waters on the northwest end of beheaded southeast-oriented flood flow channels (such as the Kerloo Creek-Perrin Creek channel) reversed flow direction to flow northwest to the newly eroded and deeper Bow Creek-Pearl Creek valley. The Kerloo Creek valley and the present day Bow Creek-Logan Creek drainage divide was created by this massive flood flow reversal.

North Elkhorn River-Middle Logan Creek drainage divide

Figure 6: North Elkhorn River-Middle Logan Creek drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the North Fork Elkhorn River-Middle Logan Creek drainage divide south and west of the figure 5 map area and includes overlap areas with figure 5. Coleridge is the town located near the east edge in the figure 6 northeast quadrant. Belden is located near the east edge in the figure 6 southeast quadrant and Randolph is the town located near the south center edge. Wausa is the town located near the west edge in the figure 6 northwest quadrant and Magnet is the small town located on the abandoned railroad line between Wausa and Randolph. Middle Logan Creek is the east-northeast oriented stream flowing from Randolph to Belden in the figure 6 southeast quadrant. Pearl Creek flows east across the figure 6 north center area and then turns northeast to flow to the figure 6 north edge. Northwest-oriented Kerloo Creek flows from near Coleridge to join Pearl Creek just north of the figure 6 map area. The North Fork Elkhorn River flows south in the figure 6 northwest quadrant and east of Wausa turns to flow in south-southwest direction to the figure 6 west center edge. The East Branch North Fork Elkhorn River flows west and south in the figure 6 southwest quadrant. Note the northwest-southeast oriented streamlining of landscape features in the figure 6 southwest region and how the North Fork Elkhorn River valley and the East Branch North Fork Elkhorn River valley have numerous short northwest and southeast oriented tributary valleys. These northwest and southeast oriented tributary valleys and through valleys eroded across the drainage divides are evidence of southeast oriented flood water flow routes that existed prior to headward erosion of the present day East Branch North Fork Elkhorn River and North Fork Elkhorn River valleys (in that sequence). Further east in figure 6 the Middle Logan Creek valley has several predominantly southeast-oriented tributaries. A close look at the tributaries reveals they are linked by northwest-southeast oriented through valleys with headwaters of northwest-oriented Pearl Creek tributaries or northwest-oriented North Fork Elkhorn River tributaries. The northwest-southeast orientation of the tributaries and the presence of the through valleys is again evidence of southeast-oriented flood water that moved across the entire figure 6 map area, probably initially on a topographic surface at least as high as the highest figure 6 elevations today. Headward erosion of the Middle Logan Creek valley first captured the flood waters in the figure 6 east half at approximately the same as the East Branch North Fork Elkhorn River was capturing flood waters in the figure 6 west half. Next headward erosion of the Pearl Creek valley beheaded flood flow to the newly eroded Middle Logan Creek valley at approximately the same time as headward erosion of the North Fork Elkhorn River valley was beheading flood flow to the newly eroded East Branch North Fork Elkhorn River and Middle Logan Creek valleys further to the west.

East Bow Creek-South Creek drainage divide area

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

Figure 7 illustrates the East Bow Creek-South Creek drainage divide area located south and east of the figure 4 map area and east of figure 5 (and includes overlap areas with figure 5). Martinsburg is the town located in the figure 7 east center area. East Bow Creek is the north-northwest and northwest oriented stream flowing to the figure 7 northwest corner. South Creek is the north-northeast oriented stream flowing from the figure 7 south edge to Martinsburg and then turning to flow east to the figure 7 east edge. Northeast-oriented Otter Creek can just barely be seen in the figure 7 southeast corner (east and south of figure 7 Otter Creek flows southeast to join northeast and southeast oriented Elk Creek, which flows to the southeast-oriented Missouri River-see figure 8 below). East of figure 7 South Creek flows in a northeast direction to join southeast-oriented Aowa Creek and the southeast-oriented Missouri River, which is located east of the figure 7 map area. Northeast-oriented Silver Creek in the figure 7 northeast quadrant also flows to southeast-oriented Aowa Creek. Daily Branch flows in a northeast and then southeast direction in the figure 7 north center area and continues to flow in southeast to join South Creek near Martinsburg. South of Daily Branch is southeast-oriented Jordan Creek, which joins South Creek upstream (south-southwest) from Martinsburg. South-southeast oriented North Logan Creek is located in the figure 7 southwest corner area. Note how South Creek has northwest and southeast oriented tributaries. Also note how the longer southeast-oriented South Creek tributaries are linked by northwest-southeast oriented through valleys with northwest-oriented East Bow Creek headwaters and/or tributaries. Similar through valleys are located across the Silver Creek and South Creek drainage north of Martinburg (and also across the drainage divide north of Silver Creek). Again the presence of multiple through valleys crossing all present day major drainage divides and the northwest-southeast orientation of trunk stream tributary valleys is evidence the trunk stream valleys eroded headward across what were then southeast-oriented anastomosing flood flow channels. Headward erosion of the trunk stream valleys occurred in sequence, with the Otter Creek valley capturing the flood flow first, the South Creek valley capturing the flood water next, and the Silver Creek valley capturing the flood water even later. Headward erosion of the Bow Creek valley occurred still later and was responsible for reversing flood flow in the present day northwest-oriented East Bow Creek drainage basin. Headward erosion of the North Logan Creek valley occurred prior to the East Bow Creek drainage basin flood flow reversal.

South Creek-Elk Creek northeast drainage divide area

Figure 8: South Creek-Elk Creek northeast drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 8 illustrates the South Creek-Elk Creek drainage divide area south and east of figure 7 and includes overlap areas with figure 7. The southeast-oriented Missouri River is located in the figure 8 northeast corner area. Allen is the town located in the figure 8 southwest corner. South Creek flows north and north-northeast from west of Allen to Martinsburg and then turns east and northeast to join southeast-oriented Aowa Creek and the Missouri River just north of the figure 8 map area. Willis is the town located in the figure 8 east center area and Goodwin is the town name southwest (or upstream) of Willis. Elk Creek is the stream flowing north from the figure 8 south edge to Goodwin and then northeast to Willis, where it turns to flow southeast to join the Missouri River east of the figure 8 map area. Waterbury is the town located in the figure 8 center south area. Otter Creek is the stream flowing northeast to near Waterbury and then turning to flow southeast to join north, northeast, and southeast oriented Elk Creek. Minnow Creek is located south of Otter Creek and flows east and northeast to join Otter Creek just before it joins Elk Creek. A close look at figure 8 drainage divides reveals the presence of multiple through valleys eroded across all major drainage divides. Further, study of trunk stream valleys reveals northeast-oriented valleys (or valley segments) almost always have northwest and southeast oriented tributaries. Further, several of the major stream have significant southeast-oriented valley segments. The complicated figure 8 drainage pattern can again be explained in the context of a massive southeast-oriented flood flow, which first moved across the entire figure 8 map area on a topographic surface at least as high as the highest figure 8 elevations today. Headward erosion of the deep southeast-oriented Missouri River valley enabled headward erosion of the present day deep figure 8 Missouri River tributary valleys in sequence (as the actively eroding Missouri River valley head eroded to the northwest). In figure 8 the deep southeast-oriented Elk Creek valley eroded headward into the region first. Note how the northwest-oriented highway follows a northwest-southeast oriented through valley linking the South Creek valley with the southeast-oriented Elk Creek valley segment. The northeast-oriented Elk Creek (and Minnow Creek) valley segment eroded headward to capture yet to be beheaded southeast-oriented flood flow and to divert the flood waters to the much deeper and newly eroded Missouri River valley. The north-oriented Elk Creek valley segment may have been eroded by a reversal of south-oriented flood water on the north end of a beheaded flood flow channel. As the deep Missouri River valley eroded headward the process was repeated with the Aowa Creek-South Creek valleys, which beheaded flood flow routes to the newly eroded Elk Creek valley.

South Creek-Elk Creek southwest drainage divide area

Figure 9: South Creek-Elk Creek southwest drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the South Creek-Elk Creek drainage divide area southwest of the figure 8 map area and includes overlap areas with figure 8. Concord is the town in the figure 9 west center edge area and Dixon is the town north of Concord. The southeast-oriented stream flowing from near Concord to the figure 9 south center edge area is Logan Creek. North Logan Creek flows southeast through Dixon to join Logan Creek southeast of Concord. The Logan Creek channel has been altered by human activity and the “Dredge” channel and the old channel are both shown. Allen is the town in the figure 9 center northeast area and South Creek flows north and northeast just west and north of Allen. Rattlesnake Creek is a northwest and west oriented South Creek tributary located just south of Allen. Note how a southeast-oriented tributary also joins north-oriented South Creek near where Rattlesnake Creek joins South Creek. Waterbury is the town located in the figure 9 northeast corner and Otter Creek flows northeast from near Allen to the figure 9 north edge near Waterbury and then turns southeast to flow through Waterbury. Southeast-oriented Elk Creek headwaters are located just south of the Rattlesnake Creek headwaters and flow to figure 9 east edge. East of figure 9 Elk Creek turns abruptly to flow in a north-northeast direction into the figure 10 map area (see below) and then to join the Missouri River (see figure 8). Middle Creek is the southeast-oriented stream in the figure 9 southeast quadrant located between Logan Creek and Elk Creek. South of figure 9 Middle Creek flows to join Logan Creek. Note how southeast-oriented Logan Creek has several relatively short south and  south-southwest oriented tributaries of which Myrtle Creek is one of the largest. Note the northwest-southeast oriented through valleys linking these Logan Creek tributaries from the north and northeast. These through valleys provide evidence of southeast-oriented flood flow that was captured by headward erosion of the deep Logan Creek valley. Note how Elk Creek and South Creek both have southeast-oriented headwaters areas before they turn to flow north. The north-oriented Elk Creek and South Creek valley segments probably were created by reversals of flood flow on the north ends of beheaded flood flow routes. The reversed flow in both cases captured yet to be beheaded flow from southeast-oriented flow routes further to the southwest. The Elk Creek reversal of flow and capture of yet to be beheaded flood flow occurred first and was followed by the South Creek reversal of flow and the capture and beheading of southeast-oriented flood flow routes to the newly eroded Elk Creek valley.

Elk Creek-Omaha Creek drainage divide area

Figure 10 illustrates the Elk Creek-Omaha Creek drainage divide area east and slightly south of the figure 9 map area. The southeast-oriented Missouri River valley can be seen in the figure 10 northeast region and the Missouri River channel is located east of the figure 10 map area. The north oriented (barbed) Missouri River tributary in the figure 10 southeast quadrant is Omaha Creek and Homer is the town located where Omaha Creek enters the Missouri River valley. Fiddlers Creek is the east-oriented tributary joining Omaha Creek near Homer. Note how Fiddlers Creek has north-northeast oriented tributary. Wigle Creek is the north- and northeast-oriented Omaha Creek tributary located south of Fiddlers Creek. Hubbard is the town located in the figure 10 north center area. The northeast-oriented stream flowing from the figure 10 center area to Hubbard and the Missouri River valley (also as a barbed tributary) is Pigeon Creek. Note how Pigeon Creek has north-oriented tributaries. Emerson is the town located in the figure 10 southwest corner. North of Emerson Elk Creek flows southeast into the figure 10 map west center edge area and then turns to flow almost straight north to the figure 10 north edge. The large number of north-oriented streams in the figure 10 map area flowing to join the south-southeast oriented Missouri River deserves an explanation. Prior to headward erosion of the deep Missouri River valley large volumes of south and south-southeast oriented flood water flowed across the entire figure 10 map region on a topographic surface at least as high as the highest present day figure 10 elevations if not higher. Headward erosion of the deep Missouri River valley beheaded these south and south-southeast oriented flood flow channels and flood waters on the north ends of these beheaded flood flow routes reversed flow direction to flow north into the newly eroded and deeper Missouri River valley. These reversals of flood flow also captured yet to be beheaded flood flow from further west. For example, reversal of flow on the Omaha Creek alignment enabled the northeast-oriented Wigle Creek valley to erode to the southwest to capture yet to be beheaded flood flow and behead and reverse the major south-oriented flood flow routes it encountered. Headward erosion of the east-oriented Fiddlers Creek valley then beheaded flood flow to the newly eroded Wigle Creek valley. Next headward erosion of the deep Missouri River valley enabled the northeast-oriented Pigeon Creek valley to erode southwest to capture south-oriented flood flow to the newly eroded Fiddlers Creek valley. Continued headward erosion of the Missouri River valley enabled the Elk Creek valley to erode northwest and southwest to capture south-oriented flood flow to the newly eroded Pigeon Creek valley and behead and reverse south-oriented flood flow routes still further to the west.

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.