The South Grand River-Little Osage River drainage divide area in Cass, Bates, and Vernon Counties, Missouri is located just east of the north-south oriented Kansas-Missouri state line and was eroded by immense south-oriented floods. Flood waters were derived from a rapidly melting North American ice sheet and were captured by headward erosion of deep east-oriented valleys in the Cass, Bates, and Vernon Counties area. Prior to headward erosion of the Little Osage River valley and its tributary Marmaton River valley flood waters were flowing to what were then newly eroded south-oriented tributary valleys which had eroded headward from what was then the newly eroded Arkansas River valley. Headward erosion of the east-oriented Little Osage River valley captured the south-oriented flood flow and diverted flood waters in an east direction to what were then newly eroded Osage River and Missouri River valleys. Headward erosion of the Marais des Cygnes River valley next beheaded south-oriented flood flow routes and diverted flood waters more directly to the newly eroded Osage River valley. Headward erosion of east-oriented South Grand River tributary valleys next, in sequence from south to north, captured south-oriented flood flow and diverted flood waters to the newly eroded South Grand River valley and Osage River valley. Evidence supporting this flood origin interpretation includes positions and orientation of major and tributary valleys and north-south oriented through valleys of various sizes crossing the present day west to east oriented drainage divides.

Preface:

The following interpretation of detailed topographic map evidence is provided as evidence in the Missouri River drainage basin landform origins research project, which is compiling similar evidence for all major drainage divides contained within the Missouri River drainage basin and for all major drainage divides with and within certain adjacent drainage basins. The research project is interpreting evidence in the context of a previously unexplored geomorphology paradigm, which is briefly described in the introduction below. Project essays are listed on the sidebar category list under their appropriate Missouri River tributary drainage basin, Missouri River segment drainage basin (by state), or states in which the Missouri River drainage basin is located.

• The purpose of this essay is to use topographic map interpretation methods to explore South Grand River-Little Osage River drainage divide area landform origins in Cass, Bates, and Vernon Counties, Missouri, 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 topographic map evidence in the South Grand River-Little Osage River drainage divide area in Cass, Bates, and Vernon Counties, Missouri will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

South Grand River-Little Osage River drainage divide area location map

Figure 1: South Grand River-Little Osage River 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 South Grand River-Little Osage River drainage divide area in Cass, Bates, and Vernon Counties, Missouri location map and illustrates regions in western Missouri and eastern Kansas. Jefferson City is the Missouri state capital and Topeka is the Kansas state capital. The Missouri River forms the southwest and southeast oriented Kansas-Missouri state line between St Joseph near the figure 1 north edge and Kansas City. South of Kansas City the state line is a north-south oriented straight line. East of Kansas City the Missouri River first flows in an east-northeast direction before turning near Brunswick, Missouri to flow in a southeast direction to Jefferson City and the figure 1 east center edge. East of the figure 1 map area the Missouri River flows to the south oriented Mississippi River. The northeast-oriented tributary joining the Missouri River near Jefferson City is the Osage River. The Osage River valley has been flooded by two large reservoirs to form Lake of the Ozarks and Harry S. Truman Reservoir. A south and southeast-oriented Osage River tributary to the Harry S. Truman Reservoir is the South Grand River, which originates in Missouri south of Kansas City. Another major Osage River is the Marais des Cygnes River, which originates in Kansas near Eskridge (south and west from Topeka) and which flows in a southeast, east-northeast, and southeast direction to join the unlabeled east-oriented Little Osage River near Schell City, Missouri. From Schell City the Little Osage River flows in an east and northeast direction to join the South Grand River and other streams in the Harry S. Truman Reservoir and to form the Osage River. West of Schell City the Little Osage River flows through Fulton, Kansas. South of the Little Osage River is the east- and northeast-oriented Marmaton River, which flows through Fort Scott, Kansas and which joins the Little Osage River near Schell City. South and west of the Marais des Cygnes River in Kansas is the southeast and south-southeast oriented Neosho River which flows through Council Grove (near the figure 1 west center edge) to Emporia and Chanute, Kansas before flowing to the figure 1 south edge. South of the figure 1 map area the Neosho River joins the southeast-oriented Arkansas River, which flows to the south-oriented Mississippi River. The Little Osage River-Spring River drainage divide area in Vernon, Barton, and Jasper Counties, Missouri(located south of the drainage divide discussed here), the Little Osage River-Neosho River drainage divide area in Bourbon and Crawford Counties, Kansas and the Marais des Cygnes River-Little Osage River drainage divide area in Miami, Linn, and Bourbon Counties, Kansas (located west of the drainage divide area described here) essays describe nearby drainage divide areas and can be found under Osage River on the sidebar category list. The Missouri River drainage basin landform origins research project essays describe hundreds of other Missouri River drainage basin drainage divides. Collectively these essays present evidence for immense south-oriented floods which flowed south from a rapidly melting North American ice sheet. Flood waters were captured by systematic headward erosion of deep east- and southeast-oriented valleys from the south-oriented Mississippi River valley (e.g. Arkansas and Missouri River valleys) and of deep tributary valleys from those major east-oriented Mississippi River tributary valleys. Valleys were eroded in sequence from south to north. In the drainage divide area described here headward erosion of the Little Osage River valley captured flood waters first. Next headward erosion of the Marais des Cygnes River valley beheaded flood flow to the newly eroded Little Osage River valley. And finally South Grand River valley headward erosion beheaded south-oriented flood flow routes to the newly eroded Marais des Cygnes River valley.

South Grand River-Little Osage River drainage divide area detailed location map

Figure 2: South Grand River-Little Osage River 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 South Grand River-Little Osage River drainage divide area in Cass, Bates, and Vernon Counties, Missouri. Cass, Bates, Vernon, Henry, and St Clair are Missouri county names and county boundaries are shown. The north-south oriented Kansas-Missouri state line is located along the Cass, Bates, and Vernon County western boundaries. Miami, Linn, and Bourbon are Kansas county names. The South Grand River flows in a southeast direction in the Cass County southwest quadrant and then in an east direction along the Cass-Bates County border before turning to flow in a southeast direction in Henry County to reach the Harry S. Truman Reservoir. A major South Grand River tributary in the Cass County southwest quadrant is north-northeast and east oriented South Fork. A major tributary in northern Bates County is east-southeast and northeast oriented Mormon Fork. The Marais des Cygnes River flows in a southeast direction from Osawatomie in Miami County across the Linn County northeast quadrant and southwest Bates County to join the east-oriented Little Osage River which then forms the Bates County-Vernon County border before flowing into St Clair County and to the Harry S. Truman Reservoir. The Little Osage River flows in an east direction near the Bourbon and Vernon County northern borders before joining the southeast-oriented Marais es Cygnes River and then forming the Vernon County north border and flowing into Harry S. Truman Reservoir where it joins the South Grand River and other steams to form the Osage River. A major southeast-oriented Marais des Cygnes River tributary in Bates is Miami Creek. Figure 1 also shows evidence of human intervention to reroute the Marais des Cygnes River channel in Bates County. Topographic maps below illustrate drainage divides between an east-oriented South Grand River tributaries in Cass County, between a north-northeast oriented South Fork tributary and a southeast and north-northeast oriented South Grand River tributary in southern Cass County, between the Mormon Fork and a south oriented Miami Creek tributariy (with Miami Creek flowing to the Marais des Cygnes River), and between the Marais des Cygnes River and Little Osage River. Evidence strongly suggests headward erosion of the east-oriented Little Osage River valley and its tributary valleys captured the south oriented flood flow first. Next headward erosion of the southeast-oriented Marais des Cygnes River valley beheaded south-oriented flood flow to the newly eroded Little Osage River valley and its tributary valleys. Mormon Fork valley headward erosion next beheaded south-oriented flood flow to actively eroding south and southeast oriented Marais des Cygnes River tributary valleys. Headward erosion of the South Grand River-South Fork valley next beheaded flood flow to the newly eroded Mormon Fork and finally further headward erosion of the South Grand River valley and its tributary valleys beheaded south-oriented flood flow routes to the newly eroded South Fork valley and tributary valleys.

Poney Creek-South Fork drainage divide area

Figure 3: Poney Creek-South Fork drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 uses reduced size maps to illustrate the Poney Creek-South Fork drainage divide area in Cass County. Harrisonville, Missouri is the city straddling the figure 3 east edge (north half). Freeman is the smaller town near the figure 3 center. Cleveland is the town located in the figure 3 northwest corner and West Line is the small town south of Cleveland. The Kansas-Missouri state line is located along the Cass County border, which is located along the figure 3 west edge. The South Grand River originates at the confluence of two south-southeast oriented tributaries (north of Freeman and east of Cleveland) and then flows is a south-southeast and southeast direction passing near Freeman to reach the figure 3 south edge (east half). Note how in the figure 3 southeast quadrant the South Grand River channel has been straightened and the old channel location is shown. Poney Creek is the east-southeast and east oriented stream flowing from the figure 3 west edge to West Line and joining the South Grand River near Freeman. South Fork is formed in the figure 3 southwest quadrant at the junction of northeast-oriented Coldwater Creek and southeast-oriented Harless Creek and then flows in a southeast and east direction near the figure 3 south edge to join the southeast-oriented South Grand River. Study of the figure 3 map area reveals shallow north-south oriented through valleys linking the east-oriented South Grand River tributary valleys. For example, several shallow north-south oriented through valleys cross the drainage divide between an unnamed east-oriented stream flowing near the figure 3 north edge from Cleveland to the South Grand River with the east-southeast and east oriented Poney Creek valley to the south. Shallow north-south through valleys can also be seen crossing the Poney Creek-South Fork drainage divide, although the through valleys are better seen on more detailed topographic maps. The shallow north-south oriented through valleys provide evidence of south-oriented flood flow channels that existed prior to headward erosion of the South Grand River valley and its east-oriented tributary valleys. At that time immense south-oriented floods moved across the figure 3 map area on a topographic surface at least as high as the highest figure 3 elevations today. Headward erosion of the east-oriented South Fork valley from what was then the actively eroding and deep South Grand River valley head captured the flood flow and diverted flood waters to the newly eroded South Grand River valley with flood waters then flowing to the newly eroded Osage and Missouri River valleys. As headward erosion of the South Grand River valley head proceeded north and west the Poney Creek valley eroded headward across the region north of the newly eroded South Fork valley and captured the south-oriented flood flow. Continued headward erosion of the South Grand River valley to the north and west enabled the unnamed east-oriented tributary valley near the figure 3 north edge to erode west and to behead south-oriented flood flow routes to newly eroded Poney Creek valley.

Detailed map of shallow north-south oriented through valleys near Cleveland

Figure 4 provides a detailed map of north-south oriented through valleys near Cleveland, Missouri which was seen in less detail in figure 3 above. The southeast-oriented South Grand River is located in the figure 4 northeast corner area. Cleveland is located in the figure 4 northwest corner. Two south-southeast oriented South Grand River tributaries meet in the figure 4 northeast corner area to form the south-southeast oriented South Grand River which can be seen meandering along and across the figure 4 east edge. An unnamed east-oriented South Grand River tributary flows from just south of Cleveland to join the South Grand River in the figure 4 northeast quadrant. Note north-oriented tributary valleys draining to that unnamed east-oriented stream. Poney Creek can be seen crossing the figure 4 southwest corner and flows in an east-southeast and east direction south of the figure 4 map area. Note south- and southeast-oriented Poney Creek tributary valleys draining to the figure 4 south edge. Further note how the north-oriented tributary valleys are linked by shallow north-south oriented through valleys with the south-oriented Poney Creek tributary valleys. Many of the shallow north-south oriented through valleys are defined by a single contour line on each side (the map contour interval is ten feet). However south of Cleveland near the figure 4 west center edge the railroad is located in a north-south oriented through valley defined by four contour lines on each side. These through valleys are water eroded features and were eroded by multiple south-oriented flood flow channels prior to headward erosion of the unnamed east-oriented South Grand River tributary valley (the one located near the figure 4 north edge). The through valleys were probably eroded by south-oriented flood flow moving to what was then the actively eroding Poney Creek valley, which was eroding headward from what was then the actively eroding South Grand River valley head. As the South Grand River valley head eroded further north the unnamed tributary valley near the figure 4 north edge eroded west and beheaded south-oriented flood flow channels to the newly eroded Poney Creek valley in sequence from east to west. Flood waters on north ends of beheaded flood flow channels reversed flow direction to erode the north-oriented tributary valleys.

South Fork-Black Creek drainage divide area

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

Figure 5 illustrates the South Fork-Black Creek drainage divide area south of the figure 3 map area and includes overlap areas with figure 3. The north-south oriented Kansas-Missouri state line is located near the figure 5 west edge. Drexel is the town located just south of the figure 5 west center edge and at the corner of Cass and Bates Counties, Missouri with Miami County, Kansas. Archie is the town located just north of the Cass County-Bates County line and adjacent to the figure 5 east edge. The south-southeast oriented South Grand River is located in the figure 5 northeast quadrant north of Archie. Southeast and east oriented South Fork flows across the figure 5 north center edge area to join the South Grand River. Owens Creek is a southeast, north, and northeast oriented South Fork tributary originating in the figure 5 north center area. Black Creek is a southeast and northeast oriented South Grand River tributary located west and north of Archie in the figure 5 east center. Mormon Fork is the south-southeast, east, southeast, and northeast oriented stream flowing from east of Drexel to the figure 5 south edge and then to the figure 5 east edge (south half). East of figure 5 the Mormon Fork joins the South Grand River. The south-oriented stream in the figure 5 southwest corner is Miami Creek, which south of the figure 5 map area flows in an south-southeast direction to join the southeast-oriented Marais des Cygnes River. The south-southwest oriented stream just barely seen at Drexel is North Sugar Creek, which also flows south to join the Marais des Cygnes River. North of Drexel the railroad is located in a shallow north-south oriented through valley linking north-oriented Coldwater Creek (flowing to South Fork) with south-oriented North Sugar Creek and Miami Creek. A close look at the figure 5 west half reveals other shallow north-south oriented through valleys. For example Harding Creek is the north-oriented South Fork tributary east of Coldwater Creek. The north-oriented Harding Creek valley is linked by a broad, but shallow through valley (north of the words CASS CO) with the southeast-oriented headwaters valley of the Mormon Fork. The through valley is a subtle feature, but it exists. The through valley linking the north- and northeast-oriented Owens Creek valley with the southeast-oriented Black Creek valley is much deeper and easier to identify. Figure 6 below provides a detailed map of the Owens Creek-Black Creek drainage divide area to better illustrate the through valley there. Note how tops of hills on either side of the Owens Creek-Black Creek through valley are at the level of the floor of the shallower through valley linking the north-oriented Harding Creek valley with the Mormon Fork valley. The depth of the Owens Creek-Black Creek through valley provides a measure of the amount of erosion the south-oriented flood waters accomplished.

Detailed map of Owens Creek-Black Creek drainage divide area

Figure 6: Detailed map of Owens Creek-Black Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 provides a detailed map of the Owens Creek-Black Creek drainage divide area seen in less detail in figure 5 above. Owens Creek flows in an east and north direction in the figure 6 northwest quadrant from the west edge to the north edge. Black Creek is the southeast-oriented stream flowing through section 27 to the figure 6 south edge. A large northwest-southeast oriented through valley links the north-oriented Owens Creek valley with the southeast-oriented Black Creek valley. The floor of the through valley at the drainage divide’s lowest point in the section 21 southeast quadrant is between 880 and 890 feet (the map contour interval is ten feet). The hill straddling the figure 6 north center edge rises to over 1000 feet and the hill in the figure 6 southwest corner also rises to more than 1000 feet. In other words the through is more than 100 feet deep and is almost two miles wide (the sections are one mile square). The through valley (and other through valleys seen in the figure 6 map area) is a water eroded feature and was eroded by south-oriented flood flow moving to what was then the southeast-oriented Black Creek valley. At that time flood waters were flowing on a topographic surface at least as high as the highest figure 6 elevations today. The deep South Fork valley north of the figure 6 map area did not exist. The deep southeast oriented South Grand River valley then eroded headward into the figure 5 map area and beheaded southwest-oriented flood flow routes to what was then the deep southeast-oriented Black Creek valley in the figure 6 map area. A reversal of flood on one of the beheaded southwest-oriented flood flow routes captured the southeast-oriented Black Creek flood flow south of the figure 6 map area to create the present day elbow of capture where Black Creek turns from flowing in southeast direction to flowing in a northeast direction (prior to that capture flood flow on the southeast-oriented Black Creek alignment was moving to the newly eroded South Grand River valley. Headward erosion of the deep east-oriented South Fork valley north of the figure 6 map area beheaded the south-oriented flood flow route into the figure 6 map area. Flood waters on the north end of the beheaded flood flow route reversed flow direction to erode the north-oriented Owens Creek valley. The reversed flood flow was aided by yet to be beheaded (by South Fork valley headward erosion) flood flow from west of the actively eroding South Fork valley head. The captured yet to be beheaded flood flow moved east to the newly reversed Owens Creek valley along what is now the east-oriented Owens Creek headwaters valley, which was eroded by that flood flow movement.

Mormon Fork-Knob Creek drainage divide area

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

Figure 7 illustrates the Mormon Fork-Knob Creek drainage divide area south of the figure 5 map area and includes overlap areas with figure 5. Adrian is the town located in the figure 7 east center area. Merwin is the smaller town located near the figure 7 west center edge. Lacyville is the place-name located on the highway midway between Merwin and Adrian. Amsterdam is the town straddling the figure 7 west edge near the southeast corner. The colored region in the figure 7 southwest corner depicts a strip mine area where probably coal seams are/were located close to the surface. The southeast-oriented South Grand River can just barely be seen in the figure 7 northeast corner. The Mormon Fork flows in a southeast, east, southeast, and northeast direction from the figure 5 north edge (west half) to join the South Grand River in the figure 7 northeast corner. Miami Creek is the southeast-oriented stream flowing from Merwin to the figure 7 south edge (west half) and south of figure 7 flows in a south-southeast direction to join the southeast-oriented Marais des Cygnes River. Knob Creek is the south-southeast oriented stream flowing from near Lacyville to the figure 7 south center edge and south of figure 7 joins Miami Creek. Note the large north-south oriented through valley linking the east-oriented Mormon Fork valley north of Lacyville with the south-oriented Knob Creek valley near Lacyville. Maps at this scale use the metric system and the map contour interval is ten meters. The through valley floor elevation is between 270 and 280 meters. The hills on either side of the through valley rise to elevations greater than 310 meters. In other words the through valley is at least 30 meters deep. The road grid is based on section boundaries and the sections are one mile square. Based on the road grid the through valley appears to be almost two miles wide. The through valley provides evidence of a major south-oriented flood flow channel eroded prior to headward erosion of the Mormon Fork valley. When the through valley channel was eroded flood waters were flowing south to the actively eroding south-oriented Knob Creek valley which had eroded headward from what were then newly eroded Miami Creek and Marais des Cygnes River valleys. Headward erosion of the deep Mormon Fork valley captured the south-oriented flood flow and diverted the flood waters east, southeast, and northeast to what was then the newly eroded South Grand River valley.

Detailed map of Mormon Fork-Knob Creek drainage divide area

Figure 8: Detailed map of Mormon Fork-Knob Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 8 provides a detailed map of the Mormon Fork-Knob Creek drainage divide area seen in less detail in figure 7 above. Burdett is the small town or cluster of buildings near the figure 8 north center edge. The Mormon Fork meanders in an east-southeast and east direction from the figure 8 north edge west of Burdett to the figure 8 east edge (near the northeast corner). Knob Creek is the south-oriented stream flowing to the figure 8 south center edge. The large north-south oriented through valley linking the Mormon Fork and Knob Creek valleys is located in sections 29 and 30. Lowest elevations where the drainage divide crosses the valley floor are between 890 and 900 feet (detailed maps have contour intervals in feet and the map contour interval is ten feet). The hill to the west of the through valley rises to an elevation greater than 1030 feet. The hill east of the through valley rises to an elevation greater than 1020 feet. In other words the through valley is at least 120 feet deep and is more than one and a half miles wide. The through valley was eroded by large volumes of south-oriented flood flow which was subsequently captured by headward erosion of the Mormon Fork valley. Prior to being captured the south-oriented flood flow was moving to what was then the actively eroding Knob Creek valley, which was eroding headward from what were then newly eroded Miami Creek and Marais des Cygnes River valleys. Headward erosion of the Mormon Fork valley from what was then the newly eroded South Grand River valley beheaded the south-oriented flood flow route to what was then the actively eroding Knob Creek valley. Flood waters on the north end of the newly beheaded flood flow route reversed flow direction to flow north to the newly eroded Mormon Fork valley, to erode the north-oriented Mormon Fork tributary valley near Burdett, and to create the Mormon Fork-Knob Creek drainage divide.

Marais des Cygnes River-Little Osage River drainage divide area

Figure 9: Marais des Cygnes River-Little Osage River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 uses reduced size maps to illustrate the Marais des Cygnes River-Little Osage River drainage divide area south of the figure 7 map area. Rich Hill, Missouri is the town located near the figure 9 east center edge. Hume is the smaller town located near the figure 9 west center edge. Foster is the town straddling the figure 9 north center edge. Sprague is the small town located midway between Hume and Rich Hill. Strip mine areas are shown and provide evidence of coal seams close to the surface and also of human disturbance of topographic features and drainage patterns. The figure 9 west edge is also the Kansas-Missouri state line. The Marais des Cygnes River meander in a southeast direction in the figure 9 northeast corner. North and northeast oriented streams in the figure 9 north half are Marais des Cygnes River tributaries. South-oriented streams flowing to the figure 9 south edge are Little Osage River tributaries and the east-oriented Little Osage River is located south of the figure 9 map area. A close look at the figure 9 map reveals shallow north-south oriented through valleys linking the north-oriented Marais des Cygnes River tributary valleys with the south-oriented Little Osage River tributary valleys. The through valleys are usually defined by a single 10-meter contour line on each side, although when looked at on a larger scale evidence for a much wider and deeper through valley can be seen. South of Hume there is a low hill with a top higher than 280 meters. Southwest of Rich Hill are isolated knobs exceeding 280 meters in elevation. Between the 280 meter plus elevations is a broad lowland where elevations along the north-south drainage divide are between 250-260 meters. This broader through valley is a subtle feature, but it exists and provides evidence of a major south-oriented flood flow route that existed prior to Marais des Cygnes River valley headward erosion. Flood waters responsible for eroding the north-south oriented through valley were (at least just before Marais des Cygnes River valley headward erosion) flowing to what was then the actively eroding Little Osage River valley. South-oriented Little Osage River tributary valleys eroded headward from that newly eroded valley. Headward erosion of the Marais des Cygnes River valley next beheaded the south-oriented flood flow routes to the actively eroding Little Osage River tributary valleys. Flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north to the newly eroded Marais des Cygnes River valley and eroded the north-oriented Marais des Cygnes River tributary valleys and created the Marais des Cygnes River-Little Osage River drainage divide.

Detailed map of Gillum Creek-Pryor Creek drainage divide area

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

Figure 10 provides a more detailed map of the Gillum Creek-Pryor Creek drainage divide area east of Hume, Missouri which was seen in less detail in the figure 9 map area above. Hume is the town straddling the figure 10 west edge. Note strip mine areas which have locally altered the landscape and drainage patterns. Gillum Creek is the north-oriented stream in section 35  flowing to the figure 10 north center edge. North of figure 10 Gillum Creek flows in a north-northeast direction to join the Marais des Cygnes River. New Home Creek is the north-oriented stream in section 36 east of Gillum Creek. North of the figure 10 map area New Home Creek turns to flow in a northeast direction and is a Marais des Cygnes River tributary. The north-oriented stream in the figure 10 northeast corner is a New Home Creek tributary. Walnut Creek is the north-oriented stream in the strip mine area located in the figure 10 northwest corner. Walnut Creek is another Marais des Cygnes River tributary. The south-oriented stream in the figure 10 southeast quadrant is Pryor Creek and other south-oriented streams flowing to the figure 10 south edge are Pryor Creek tributaries. South of the figure 10 map area Pryor Creek flows in a south-southeast direction to join the east-oriented Little Osage River. Note the low hill east of Hume where the hill-top rises to an elevation greater than 930 feet (the map contour interval is ten feet). Also note the low hill in section 14 near the figure 10 south center edge where the elevations rise to at least 910 feet. Further note the hill in the figure 10 southeast corner where elevations rise to more than 910 feet (a short distance east of the figure 10 map area there are elevations greater than 930 feet). The broad drainage divide in sections 12 and 1 between north-oriented New Home Creek and Gillum Creek and south-oriented Pryor Creek has low elevations of between 870 and 880 feet and is generally lower than 900 feet. This shallow north-south oriented through valley is actually a sub through valley located within the larger through valley described in figure 9. The north-south oriented through valleys provide evidence of immense south-oriented floods that flowed across the figures 9 and 10 map areas prior to headward erosion of the Marais des Cygnes River valley. Before being beheaded and reversed by Marais des Cygnes River valley headward erosion flood waters were flowing to what was then the actively eroding south-oriented Pryor Creek valley and tributary valleys which had eroded headward from what was then the newly eroded Little Osage River valley.

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.