• The purpose of this essay is to use topographic map interpretation methods to explore the Platte River-Missouri River drainage divide area landform origins in Clinton and Clay 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 essays in the Missouri River drainage basin landform origins research project 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 Platte River-Missouri River drainage divide area landform evidence in Clinton and Clay Counties, Missouri will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm (see menu at top of page for paradigm related essay). This essay is included in the Missouri River drainage basin landform origins research project essay collection.

Figure 1: Platte River-Missouri River drainage divide area in Clinton and Clay Counties, Missouri location map (select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

 

• Figure 1 illustrates a location map for the Platte River-Missouri River drainage divide area in Clinton and Clay Counties, Missouri and illustrates a large region in the state of Missouri. The south-oriented Mississippi River is located in the figure 1 northeast quadrant and forms the boundary between Missouri to the west and Illinois to the east. The Missouri River flows in a south-southeast direction from the figure 1 northwest corner to Kansas City and then in an east-northeast direction to Brunswick, Missouri. From Brunswick the Missouri River flows in a southeast direction to Jefferson City and then in an east direction to join the Mississippi River east of the figure 1 map area. Kansas is west of Missouri except in the figure 1 northwest corner area where Nebraska is west of the Missouri northwest corner. The Platte River flows from the figure 1 north edge in a south direction to join the Missouri River near Platte City, which is located a short distance upstream from Kansas City. The south-oriented One Hundred and Two River is located west of the Platte River north of St. Joseph, Missouri and joins the Platte River near St. Joseph. Note how the Missouri River and Platte River nearly meet near St. Joseph and the Missouri River then turns to make a jog to the southwest before turning to flow in a southeast direction again. The Platte River segment of interest in this essay is located south of St. Joseph and the drainage divides of interest are located east of the Platte River. A separate essay addresses drainage divides west of the Platte River (and south of St. Joseph) and is titled: Missouri River-Platte River drainage divide landform origins in Buchanan and Platte Counties, Missouri (side MO Missouri River list of essays under sidebar category list). Platte River tributaries from the east are not labeled in figure 1, but can be seen flowing in a south direction from the Stewartsville area (east of St. Joseph) and then turning to flow in southwest and west directions to join the south-oriented Platte River. This essay focuses on drainage divides between those Platte River tributaries and also on drainage divides between those tributaries and east-, southeast, and south oriented Missouri River tributaries located east and south of the easternmost of the illustrated Platte River tributaries. With the exception of Shoal Creek (east of Stewartsville), which flows to the southeast and south oriented Grand River before its water reaches the Missouri River, other Missouri River tributaries of interest are unlabeled on the figure 1 map and flow in southeast and south directions to reach the Missouri River in the region downstream from Kansas City.

• Based on evidence presented in other Missouri River drainage basin landform origins research project essays and evidence shown in figures illustrated below the Platte River-Missouri River drainage divide area in Clinton and Clay Counties was eroded by immense south-oriented floods. Flood waters were derived from a rapidly melting thick North American ice sheet, which had been located in a deep “hole” north of the figure 1 map area. The figure 1 map area would have been located on the deep “hole’s” southern rim, and was probably deeply eroded by melt water floods. No markers remain to indicate how much material was removed from the figure 1 map area surface prior to events which resulted in headward erosion of present day drainage route valleys into the figure 1 map area. Also flood water erosion and deposition has probably so confused evidence that the ice sheet’s maximum southern margin may never be accurately determined. What can be determined from topographic map evidence is all valleys for figure 1 drainage routes eroded headward into the figure 1 map area to capture gigantic south-oriented floods at a time when the decaying ice sheet’s southern margin was located in southeast South Dakota and southwest Minnesota (located north of the figure 1 map area). Initially flood waters probably overwhelmed whatever drainage system existed before and flowed in a south direction across the entire figure 1 map area to eventually reach the Gulf of Mexico. The south-oriented flood waters were then captured by headward erosion of deep southeast and east oriented tributary valleys from what was probably an actively eroding Mississippi River valley. Captures occurred in sequence from south to north and from east to west. For example, in the state of Arkansas, south of the figure 1 map area, headward erosion of the southeast-oriented Arkansas River valley captured the south-oriented flood flow before headward erosion of the southeast-oriented White River valley beheaded flood flow routes to the newly eroded Arkansas River valley. Headward erosion of the Missouri River valley (and its east and northeast-oriented tributary valleys located south of the Missouri River) next beheaded south-oriented flood flow routes to the newly eroded White River valley. North-oriented tributary valleys were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes (this process will be further discussed below).

Figure 2: Detailed location map for Platte River-Missouri River drainage divide areas in Clinton and Clay Counties. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 2 provides a detailed location map for the Platte River-Missouri River drainage divide area in Clinton and Clay Counties, Missouri. County names and boundaries are shown. Between the figure 2 northwest corner and Kansas City the Missouri River forms the Kansas-Missouri state line. Doniphan and Leavenworth Counties are in Kansas and Buchanan and Platte Counties are in Missouri. East of Kansas City the Missouri River meanders in an east direction to the figure 2 east edge. The Platte River flows in a south direction from the figure 2 north edge across eastern Buchanan County and into northeast Platte County and then turns to flow in a south-southwest direction to join the Missouri River. Major Platte River tributaries from the east include the Little Platte River, which originates near Osborn (on the De Kalb-Clinton County line) and which flows in a south-southwest direction to the Clay County northwest quadrant before turning to flow in a west direction to join the Platte River in the Platte County northeast quadrant. The Little Platte River has several unnamed (on figure 2) northwest and northeast oriented tributaries in the Clay County northwest quadrant and the Platte County northeast quadrant. South of these tributaries are headwaters of south- and southeast-oriented Missouri River tributaries. An unnamed southwest and west oriented tributary also joins the Little Platte River in northwest Clay County, although Little Platte River tributaries from the east are rare. Shoal Creek originates in eastern Clinton County (north of Lathrop) and flows in a northeast direction into northwest Caldwell County and then after making turns in various directions flows to the southeast-oriented Grand River in Livingston County. East of the figure 2 map area the Grand River flows to the Missouri River near Brunswick, Missouri (see figure 1). South of Lathrop in Clinton County are south-southwest oriented headwaters of Clear Creek which flow into northeast Clay County and then turn to flow in a southeast direction to join the southeast-oriented Fishing River, which joins the Missouri River in western Ray County. Also originating near Lathrop in Clinton County are northeast-oriented headwaters of Crooked River, which in the Caldwell County southwest corner turn to flow in a southeast direction to join the Missouri River in eastern Ray County. West and north of the Little Platte River is south and southwest oriented Castile Creek, which originates near Amity in western De Kalb County and which joins the Platte River near the Buchanan-Platte County border. North and west of Castile Creek is the south- and southwest-oriented Third Fork Platte River which joins the Platte River in the Buchanan County northeast quadrant. Discussions below begin by looking at drainage divides between the Platte River tributaries mentioned and conclude with a look at drainage divides between the Little Platte River and its tributaries and various Missouri River tributaries.

Figure 3: Third Fork Platte River- Castile Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 3 illustrates the Third Fork Platte River-Castile Creek drainage divide area in the Buchanan-De Kalb-Clinton County corner area. The Buchanan-De Kalb-Clinton County corner is located just west of the figure 3 north center area and is labeled. The Platte River flows in a south direction along the figure 3 west edge. The Third Fork Platte River flows in a south-southwest direction from the figure 3 north edge to join the Platte River in the figure 3 northwest quadrant. Note northwest oriented Riley Branch which flows to Platte River at approximately the same point where the south-southwest oriented Third Fork joins the Platte River. Also note how the Riley Branch has southwest-oriented headwaters and a significant north oriented tributary. The north and northwest oriented valleys were eroded by reversals of flood flow on north and northwest ends of beheaded south oriented flood flow channels. The flood flow channels were beheaded by headward erosion of the deep south oriented Platte River valley from the deep and newly eroded Missouri River valley. East of the southwest-oriented Riley Branch headwaters along the Buchanan-Clinton County line are headwaters of south oriented Malden Creek, which flows in a south, west, and south direction to figure 3 south edge (west half). North of the south-oriented Malden Creek headwaters is a northwest and north oriented tributary to northwest and north oriented Jordan Creek, which flows to the southwest-oriented Third Fork Platte River as a barbed tributary. Stewartsville is the town located in the figure 3 northeast quadrant and is located adjacent to south-southwest oriented Castile Creek, which flows to the figure 3 south edge (near the small town of Starfield). Mc Guire Branch is the south- and southeast-oriented tributary joining Castile Creek just south of Starfield. Rogers Branch is the south and southeast-oriented Mc Guire Branch tributary located in the figure 3 center area (and south of the small town of Hemple). Note how some Castile Creek tributaries from the east also have north oriented tributaries. The north and northwest-oriented barbed tributaries to what are south-oriented streams flowing to a south-oriented river provide evidence of major flood flow reversals along north and northwest ends of beheaded south- and southeast-oriented flood flow channels. Study of drainage divides at heads of south-oriented streams and of north oriented barbed tributaries reveals shallow through valleys linking north- and south-oriented valleys. The shallow through valleys are easier to see on more detailed topographic maps and figure 4 below provides a detailed map of the Riley Branch-Malden Creek drainage divide area to better illustrate through valleys there. A north-south oriented through valley visible on the figure 3 map links the south-oriented Malden Creek valley with the north-oriented Jordan Creek tributary valley (the map contour interval in ten meters and the through valley is defined by one contour line on each side).

Figure 4: Detailed map of Riley Branch-Malden Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 4 provides a detailed topographic map of the Riley Branch-Malden Creek drainage divide area seen in less detail in figure 3 above. Riley Branch flows in a southwest and then northwest direction near the figure 4 northwest quadrant north edge. A major north-northeast and north oriented tributary originates in the figure 4 southwest quadrant and joins Riley Branch just east of the word “Riley” near the figure 4 north edge. This north-oriented Riley Branch tributary has southeast-oriented tributaries from the west and northwest-oriented tributaries from the east. Malden Creek flows in a south direction in the figure 4 northeast quadrant and turns in the east center area to flow in a southwest, west, and southwest direction to the figure 4 south center edge. Note how Malden Creek has south and south-southeast oriented tributaries from the north and north-oriented tributaries from the south. West and northwest oriented drainage flowing to the figure 4 west edge flows directly to the south-oriented Platte River which is located just west of the figure 4 map area. Several shallow through valleys can be seen linking northwest-oriented tributary valleys to the north-oriented Rile Branch tributary with the south-southeast oriented Malden Creek tributary valleys. One of the most obvious shallow through valleys is located in the section 18 northeast quadrant. The map contour interval is 20 feet and the through valley floor elevation is between 960 and 980 feet. Elevations in the figure 4 northeast quadrant rise to more than 1040 feet while in the southwest quadrant elevations rise to more than 1020 feet. A slightly shallower through valley is located in the section 8 southwest quadrant and even shallower through valleys can be seen in the section 8 northeast quadrant. Other shallow through valleys can be seen linking the north-oriented Riley Branch tributary valley with west-oriented Platte River tributary valleys in the figure 4 southwest quadrant. The north- and northwest-oriented barbed tributaries, the shallow through valleys, and the valley orientations all provide evidence of what were once south-oriented flood flow channels in what was once a large south-oriented anastomosing channel complex. Headward erosion of the deep south-oriented Malden Creek valley (from the actively eroding Platte River valley) captured south-oriented flood flow routes which were subsequently beheaded and reversed by Platte River valley headward erosion.

Figure 5: Detailed map of Platte River-Castile Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 5 illustrates the Platte River-Castile Creek drainage divide area located south of the figure 3 map area and includes overlap areas with figure 3. Garrettsburg is the town located in the northwest corner area, Plattsburg is the town located in the southeast corner, Gower is the town located in the figure 5 south center area, and Starfield is the place-name near the figure 5 east center. The north-south oriented Buchanan-Clinton County boundary line is located near the figure 5 center. The south oriented Platte River is located near the figure 5 west edge. Southwest and northwest oriented Riley Branch can be seen along the figure 5 north edge. Other Platte River tributaries from the east are short, although several are oriented in northwest directions suggesting erosion of valleys by reversals of flood flow on north ends of beheaded flood flow routes. Malden Creek flows in a south direction from the figure 5 north center edge before making a jog to the west and then flowing in a south and south-southwest direction to join southwest-oriented Castile Creek near the figure 5 south edge (near the word PLATTE). In addition to through valleys seen in figures 3 and 4 an old railroad grade crosses the Platte River-Malden Creek drainage divide on the floor of a through valley near the small town of Frazier in the figure 5 west center area. The through valley is defined by two 10-meter contour lines and other shallower through valleys can be identified. Wolfpen Creek is the south-southwest oriented Malden Creek tributary joining Malden Creek where the old railroad grade crosses Malden Creek. Note how Wolfpen Creek headwaters are directly south of the south-oriented Malden Creek segment in the figure 5 north center area. Also note how shallow through valleys link the south-oriented Malden Creek valley segment with the Wolfpen Creek headwaters valley. Castile Creek flows from the figure 5 north edge (near northeast corner)  in a south-southwest and southwest direction to the figure 5 south edge (near the word PLATTE). Roberts Branch is the south-southwest and south oriented stream in the figure 5 southeast corner area and is a Little Platte River tributary. Note north and northwest oriented Castile Creek tributaries from the south and east and south- and southeast-oriented tributaries from the north and west. Additional shallow through valleys can be seen along drainage divides between Castile Creek tributaries. For example the south-oriented unnamed tributary east of Gower is linked by a shallow through valley with a north- and northeast-oriented tributary valley to the southeast-oriented Mc Guire Branch valley to the north. Also just to the west of Gower two north-south oriented through valleys link the Wolfpen Creek valley with the Jenkins Branch valley and then the Jenkins Branch valley with the Castile Creek valley and provides evidence of a south-southeast oriented flood flow channel that was first captured by Castile Creek valley headward erosion, next captured by Jenkins Branch valley headward erosion, and still later captured by Wolfpen Creek valley headward erosion. The former flood flow channel can be followed to the northwest across the Wolfpen Creek-Malden Creek drainage divide and across the Malden Creek-Platte River drainage divide. West of the figure 5 map the former flood flow can be traced still further to the northwest towards the Missouri River elbow of capture near St. Joseph.

Figure 6: Little Platte River-Muddy Fork drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 6 illustrates the Little Platte River-Muddy Fork drainage divide area located east and south of the figure 5 map area and includes an overlap area with figure 5. Plattsburg is the town located in the figure 6 northwest quadrant and Lathrop is the town located slightly north and east of the figure 6 center. Wexford is a place-name located midway between Plattsburg and Lathrop. The Clinton County east boundary is located near the figure 6 east edge. The river meandering in a southwest direction across the figure 6 northwest quadrant is the Little Platte River, which west of the figure 6 map area turns to flow in more of a west direction to join the south-oriented Platte River. Note how the Little Platte River has several northwest and north oriented tributaries, such as the west, southwest, and north-northwest oriented tributary flowing through Wexford. A north and northwest oriented tributary flows to that tributary at its elbow of capture (where it turns to flow in a north-northwest direction). The south-oriented stream located south of Wexford and flowing to the figure 6 south edge is Clear Creek, which south of the figure 6 map area flows in a south-southeast direction to southeast-oriented Fishing River, which flows to the Missouri River. Observe how the south-oriented Clear Creek headwaters valley is linked by a shallow through valley with the north- and northwest-oriented Little Platte River valley. The map contour interval is ten meters and the through valley is defined by a single contour line on each side. The south-southwest stream flowing through Lake Arrowhead to the figure 6 south center edge is Muddy Fork, which south of the figure 6 map area joins Clear Creek. The north and northeast oriented stream originating north of Lathrop is the headwaters of Shoal Creek with north and north-oriented Little Shoal Creek just east of Lake Mc Guiness. North of the figure 6 map area Little Shoal Creek joins Shoal Creek and Shoal Creek eventually joins the southeast-oriented Grand River, which eventually joins the Missouri River (see figures 1 and 2). The northeast and east-oriented stream flowing to the figure 6 east edge east of Lathrop is the headwaters of the southeast-oriented Crooked River which eventually joins the Missouri River (see figure 2). Study of the figure 6 map area reveals additional shallow through valleys linking north-oriented valleys with south-oriented valleys. The figure 6 map evidence suggests headward erosion of the Shoal Creek valley beheaded and reversed south-oriented flood flow to the south-oriented and actively eroding Muddy Fork and Clear Creek valleys at about the same time Little Platte River valley headward erosion beheaded and reversed south-southeast oriented flood flow to the actively eroding Clear Creek valley.

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

 

• Figure 7 illustrates the Castile Creek-Little Platte River drainage divide area located south of figure 5 and west of figure 6 and includes overlap areas with both figures 5 and 6. The Little Platte River meanders in a south-southwest and west direction from the figure 7 northeast corner to Plattsburg and then enters Smithville Lake, which is a large reservoir flooding the south-southwest oriented Little Platte River valley. Headwaters of south oriented Clear Creek can be seen in the figure 7 southeast corner. Horse Fork is the south oriented tributary joining the Little Platte River near Plattsburg. Roberts Branch is the south-southwest oriented tributary flowing from the figure 7 north edge (east half) to join the Little Platte River near the figure 7 south center edge. Note other south and southeast-oriented Little Platte River tributaries from the north and west. The Platte River flows in a south direction near the figure 7 west edge. Gower is the town near the figure 7 northwest quadrant north edge. The south-southwest and west-southwest tributary flowing from the figure 7 north center edge to join the Platte River in the northwest quadrant is Castile Creek. Note how Castile Creek tributaries from the south and east are generally oriented in north and northwest directions. Also note how north and northwest oriented Castile Creek tributary valleys are linked by shallow through valleys with south-oriented Little Platte River tributary valleys. For example, just north and west of Grayson (a place south the figure 7 center) several shallow through valleys can be seen linking north-northwest oriented Castile Creek tributary valleys with a south-southeast oriented Little Platte River tributary valley. Further west and north somewhat more subtle shallow through valleys cross the Castile Creek-Roberts Branch drainage divide located between Gower and Plattsburg. Valley orientations and the through valleys provide evidence of south- and southeast-oriented flood flow routes to the actively eroding Little Platte River valley, which captured the south- and southeast oriented flood flow before flood flow routes were beheaded and reversed by Castile Creek valley headward erosion. Headward erosion of the Castile Creek valley beheaded and reversed the south-oriented flood flow routes, which had been flowing on a surface at least as high as the present day drainage divide to what were then actively eroding south- and southeast-oriented Little Platte River tributary valleys. The flood flow reversals eroded the north-oriented Castile Creek tributary valleys.

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

 

• Figure 8 provides a detailed topographic map of the Castile Creek-Linn Branch drainage divide area seen in less detail in figure 7 above. Grayson is the town located in the figure 8 south center area. Linn Branch is the south-southeast oriented stream flowing to the figure 8 south edge located south of Grayson and south of the figure 8 map area flows to the southwest-oriented Little Platte River. Other south-oriented drainage routes flowing to the figure 8 south edge are also Little Platte River tributaries. Northwest and north oriented streams flowing to the figure 8 north edge are Castile Creek tributaries. Close study of figure 8 drainage divides shows numerous shallow through valleys linking the north oriented Castile Creek tributary valleys with the south-oriented Little Platte River tributary valleys and also linking north oriented Castile Creek tributary valleys and south-oriented Little Platte River tributary valleys with each other. For example in the section 5 northwest quadrant a shallow through valley links the northwest-oriented headwaters valley of a north oriented Castile Creek tributary with a southeast-oriented Linn Branch tributary valley. The map contour interval is ten feet and the through valley floor elevation is between 1000 and 1010 feet. Elevations rise to more than 1040 feet on either side of the through valley. At least five additional somewhat shallower through valleys linking north-oriented Castile Creek tributaries with south-oriented Linn Branch tributaries can be seen in sections 25 and 26 and provide evidence of multiple converging south-oriented flood flow channels to what was once the actively eroding Linn Branch valley. At the time flood waters flowed south across the figure 8 map area and eroded the through valleys headward erosion of the deep Little Platte River valley south of the figure 8 map area had captured the south-oriented flood flow and deep south- and southeast-oriented tributary valleys were eroding north from the newly eroded Little Platte River valley. At that time the deep Castile Creek valley north of the figure 8 map area had not yet been eroded and flood waters were still flowing on a surface at least as high as the present day Castile Creek-Little Platte River drainage divide. Headward erosion of the deep Castile Creek valley beheaded south-oriented flood flow channels in sequence from the west to the east. Flood waters on north and northwest ends of beheaded flood flow routes reversed flow direction to erode the north- and northwest-oriented Castile Creek tributary valleys. Castile Creek valley headward erosion beheaded flood flow channels one channel at a time so it was possible for reversed flood flow in a newly reversed flood flow channel to capture flood waters still moving in adjacent flood flow channels. Such captures of yet to be beheaded flood flow provided water volumes required to erode the north-oriented tributary valleys and also account for the shallow through valleys crossing Castile Creek tributary drainage divides.

Figure 9: Little Platte River-Missouri River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

Figure 9 illustrates the Little Platte River-Missouri River drainage divide area south and slightly west of the figure 7 map area. The Little Platte River flows in a west direction from the dam impounding Smithville Lake and is located near the north edge of the figure 9 northwest quadrant. Smithville is the town located just downstream from the dam. Note the northwest and north-northeast oriented Little Platte River tributaries from the south. East of Smithville the tributaries tend to be oriented in northwest directions while east of Smithville they tend to be oriented in north-northeast directions although they have northwest-oriented headwaters and tributaries. Streams flowing to the figure 9 south edge tend to be oriented in southeast and south-southeast directions and are tributaries to the east-oriented Missouri River located south of the figure 9 map area. The northeast and southeast oriented stream in the figure 9 east center area and flowing to the figure 9 east center edge is the Fishing River, which is a Missouri River tributary. Note how the northeast-oriented Fishing River segment has several southeast-oriented tributaries. Note how headwaters of the north-oriented Little Platte River tributaries are aligned in the same direction as the southeast-oriented Missouri River (and Fishing River) tributaries located just to the south. Study of the figure 9 Little Platte River-Missouri River drainage divide reveals some shallow through valleys linking north-oriented Little Platte River tributary valleys with south-oriented Missouri River tributary valleys, however more detailed topographic maps are needed to better see the presence of through valleys. Figure 10 below provides a detailed topographic map of the First Creek-Shoal Creek drainage divide area located south of Nashua (located south of Smithville) to better illustrate through valleys in that region. The figure 9 map evidence suggests the deep east-oriented Missouri River valley (located south of the figure 9 map area) eroded headward into and across the region to capture south-and southeast-oriented flood flow prior to headward erosion of the west-oriented Little Platte River valley to the north. Southeast and south-southeast oriented tributary valleys then began to erode headward from the newly eroded Missouri River valley along the southeast and south-southeast oriented flood flow routes. Headward erosion of the deep west-oriented Little Platte River valley from the deep south-oriented Platte River valley (west of the figure 9 map area) next beheaded the south-southeast and southeast oriented flood flow routes. Flood waters on north ends of the beheaded flood flow routes reversed flow direction to erode the north, north-northwest, northwest, and north-northeast oriented tributary valleys.

Figure 10: First Creek-Shoal Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 10 provides a detailed topographic map of the First Creek-Shoal Creek drainage divide seen in less detail in figure 9 above (the Shoal Creek shown in figures 9 and 10 is a different Shoal Creek from the Shoal Creek shown in figure 6). Nashua is the town located south of the figure 10 north center edge and Gashland is the town located along the figure 10 south center edge. The northwest and north oriented stream originating south of Nashua and flowing to the figure 10 north edge (west half) is First Creek and flows to the Little Platte River. Rock Branch is the north-oriented stream with headwaters in the Nashua city limits and is also a Little Platte River tributary. Northwest-oriented streams flowing to the figure 10 west edge are Second Creek headwaters and tributaries. North of the figure 10 map area Second Creek turns to flow in a north-northeast direction and joins with First Creek before reaching the Little Platte River near Smithville (see figure 9). Shoal Creek is the south-oriented stream originating in the figure 10 center area (near the words KANSAS CITY) and flowing in a south, southeast, and south direction to the figure 10 south edge just east of Gashland. South of the figure 10 map area Shoal Creek flows in a south-southeast and southeast direction to join the east-oriented Missouri River. Southeast-oriented streams flowing to the figure 10 east edge are Shoal Creek tributaries. The south-oriented stream in the figure 10 southwest corner is Line Creek, which south of the figure 10 map area flows in a south direction to join the Missouri River. Shallow through valleys can be seen linking the north-oriented Little Platte River tributary valleys with the south-oriented Missouri River tributary valleys. For example in the section 26 southeast quadrant a shallow through valley links a northwest-oriented First Creek tributary valley with a south-oriented Shoal Creek headwaters valley. Other shallow through valleys linking opposing tributary valleys can be seen in the section 35 northwest quadrant and the section 34 northeast quadrant. East of Nashua shallow through valleys can be seen linking the north-oriented Rock Branch valley with south-southeast oriented Shoal Creek tributary valleys and in sections 3 and 4 in the figure 10 southwest quadrant shallow through valleys link north-oriented Second Creek headwaters and tributary valleys with south-oriented Line Creek headwaters and tributary valleys. The through valleys are not deep and are usually defined by fewer than four ten-foot contour lines on a side. However, the through valleys provide evidence of multiple south-oriented flood flow channels such as might be found in a south anastomosing channel complex. Headward erosion of the east-oriented Missouri River valley first captured the south-oriented flood flow and Little Platte River subsequently beheaded and reversed the flood flow.

Additional information and sources of maps studied