A geomorphic history based on topographic map evidence

The Sheyenne River-James River drainage divide area discussed here is located south of Baldhill Creek and is located in North Dakota, USA. Baldhill Creek is a Sheyenne River tributary and the Baldhill Creek drainage basin is included in the drainage divide area investigated here The James River-Sheyenne River drainage divide is the north-south continental divide, with water in the Sheyenne River eventually reaching Hudson Bay in the north and water in the James River eventually reaching the Gulf of Mexico in the south. Evidence in the drainage divide area makes a strong case the north-south continental divide was created when the eastern half of an immense south-oriented melt water river flowing in an ice-walled and bedrock-floored valley was captured and diverted to flow north while the river’s western half continued to flow south.

• The purpose of this essay is to use topographic map interpretation methods to explore James River-Sheyenne River drainage divide area landform origins south of Baldhill Creek, North Dakota, 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 James River-Sheyenne River drainage divide area landform evidence south of Baldhill Creek, North Dakota 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.

James River-Sheyenne River drainage divide area location map

Figure 1: James River-Sheyenne 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 James River-Sheyenne River drainage divide area location map. The state of Minnesota is located along the figure 1 east edge area. South Dakota is the state west of Minnesota and located along the figure 1 south edge. The remainder of figure 1 (which represents most of the area shown) is located in North Dakota. The Missouri River is located along the figure 1 west edge area and flows south-southeast past Bismarck and into Lake Oahe, which is a large reservoir flooding the Missouri River valley. Missouri River water eventually reaches the Gulf of Mexico. The Red River flows north from Wahpeton, North Dakota and is the boundary between North Dakota and Minnesota. Red River water eventually reaches Hudson Bay. The Sheyenne River originates southwest of Harvey in the figure 1 northwest corner and flows east, northeast and then east across the figure 1 north center area before turning to flow south to Lake Ashtabula (a reservoir flooding the Sheyenne River valley), Valley City, and Ft. Ransom. At Ft. Ransom the Sheyenne River begins to make a U-turn and turns to flow in a northeast direction to join the north-oriented Red River just north of Fargo, North Dakota. Baldhill Creek is the unnamed southeast-oriented tributary joining the Sheyenne River at Lake Ashtabula. East of the south-oriented Sheyenne River segment is the south-oriented Maple River, which also makes a U-turn to flow northeast to the north-oriented Red River. The James River also originates near Harvey and flows east and southeast to near Grace City, where it turns to flow south and southeast to Jamestown. Pipestem Creek is a southeast-oriented James River tributary. From Jamestown the James River continues by flowing southeast and south into South Dakota and south of the figure 1 map area joins the Missouri River in southeast South Dakota. The north-south continental divide is located between the James and Sheyenne Rivers. Water in the Sheyenne River (and in Baldhill Creek) eventually reaches Hudson Bay in northern Canada. Water in the James River eventually reaches the Gulf of Mexico. Between the James River and the Missouri River is a northwest-southeast and north-south oriented region without an integrated drainage pattern. That region is the Missouri Coteau and is bounded on the northeast and east by the northeast and east-facing Missouri Escarpment. The Missouri Coteau is illustrated and described in other essays (e.g.Missouri River-Sheyenne River and Missouri River-Apple Creek-Pipestem Creek drainage divide area essay found under ND Missouri River on the sidebar category list) and is interpreted to be where the detached southwest margin of a thick ice sheet melted. The James River valley and Pipestem Creek valleys are interpreted to have been eroded in what was the floor of an ice-walled and bedrock-floored valley sliced by immense south-oriented melt water floods into a rapidly melting thick ice sheet surface. The Missouri Escarpment is interpreted to be what remains of that ice-walled and bedrock-floored valley’s southwest and west wall. The James River-Sheyenne River drainage divide area discussed in this essay is located south of the Baldhill Creek headwaters near Grace City, North Dakota. The Sheyenne River-James River drainage divide area essay illustrates and discusses the drainage divide area in Wells, Benson, and Eddy Counties to the north (essay can be found under James River on sidebar category list) .

James River-Sheyenne River drainage divide area detailed location map

Figure 2 provides a somewhat more detailed map of the James River-Sheyenne River drainage divide area discussed in this essay. Foster, Griggs, Steele, Trail, Stutsman, Barnes, Cass, La Moure, Ransom, and Richland are North Dakota counties. The James River flows south in Foster County into Stutsman County and to Jamestown, where it makes a jog to the southeast and flows south and southeast into La Moure County and then to the figure 2 south edge. Two James River tributaries of interest are south-oriented Sevenmile Coulee (located east of Jamestown) and which joins the James River southeast of Jamestown, and south-oriented Bear Creek, which flows south along the La Moure County-Ransom County line and joins the James River south of the figure 2 map area. Pipestem Creek is a James River tributary joining the James River at Jamestown (the Pipestem Creek-James River drainage divide area is discussed in a separate essay found under James River on sidebar category list).  The Sheyenne River flows south in eastern Griggs County and then south through the center of Barnes County into northeast Ransom County. In Ransom County the Sheyenne River makes a U-turn to flow northeast to join the north oriented Red River, which is located in the figure 2 east edge area. East of the south-oriented Sheyenne River is the south-oriented Maple River, which flows south through western Cass County before making an abrupt at Enderlin turn to flow northeast. Baldhill Creek originates in eastern Foster County and flows southeast to join the Sheyenne River at Lake Ashtabula, which is located in Barnes County north of Valley City. West of the James River and southwest of Pipestem Creek is a region lacking an integrated drainage pattern and characterized in figure 2 by many small lakes. That region is the Missouri Coteau and is interpreted to be where the detached margin of a thick ice sheet melted and deposited whatever debris it contained. The northeast and east-facing Missouri Escarpment marks the boundary between the Missouri Coteau and the southeast oriented Pipestem Creek and James River valleys and is interpreted to be what remains of the ice-walled and bedrock-floored valley southwest wall, which was formed when an immense southeast and south-oriented melt water river sliced a deep ice walled and bedock floored canyon into a rapidly melting thick ice sheet surface, and which detached the ice sheet’s southwest margin.

James River-Baldhill Creek drainage divide area

Figure 3: James River-Baldhill Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the James River-Baldhill Creek drainage divide area near Grace City, North Dakota. Grace City is located in the figure 3 northwest quadrant. The James River is the southeast oriented stream south of Grace City and enters the south-southwest and south oriented Juanita Lake outlet valley to flow to the figure 3 south edge. Baldhill Creek originates at Stony Lake in Florance Township (figure 3 north center) and flows southeast and then northeast to the figure 3 east edge. This figure 3 map area is located on the floor of what was the large southeast and south-oriented ice-walled and bedrock-floored valley that detached the thick ice sheet’s southwest margin. Note how the Baldhill Creek headwaters area is linked by a shallow through valley with Juanita Lake, which drains to the James River. The through valley provides evidence southeast-oriented water once flowed from Juanita Lake and the present day James River drainage basin to the Baldhill Creek drainage basin, and probably was responsible for eroding the Baldhill Creek valley. What is particularly interesting about this shallow and rather insignificant looking through valley is it crosses North America’s north-south continental drainage divide. Water in Juanita Lake drains to the James River and eventually reaches the Gulf of Mexico. Water in Stony Lake drains to Baldhill Creek and the Sheyenne River and eventually reaches Hudson Bay. Further complicating the figure 3 interpretation is evidence the figure 3 landscape has been glaciated. The small lakes and ponds and hummocky topography suggest the figure 3 region is underlain with glacially deposited materials, in which remnant ice masses were probably buried and which subsequently melted. Some of the larger hills, such as the hill northwest of Juanita Lake, may have been formed when slabs of frozen bedrock attached to wet-based thin ice sheets were lifted and moved short distances. While the entire figure 3 map area appears to have been glaciated, areas east of the James River and south Baldhill Creek have the characteristics of a glacial outwash plain, suggesting deposition by large volumes of glacial melt water. These figure 3 landscape features suggest the presence of thin wet based ice sheets at a time when southeast- and south-oriented melt water floods moved across the region. Such thin wet based ice sheets could have formed by freezing of melt water floods on the thick ice sheet floor. And subsequent melt water floods could account for headward erosion of the Baldhill Creek valley from the Sheyenne River valley. Subsequently headward erosion of the James River (and Jaunita Lake valley)  beheaded southeast-oriented flood flow to the newly eroded Baldhill Creek valley. Probably these valleys eroded headward into an ice-covered region (perhaps by thin ice sheets).

Baldhill Creek-Sheyenne River drainage divide area

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

Figure 4 illustrates the Baldhill Creek-Sheyenne River drainage divide area south and east of the figure 3 map area. The Sheyenne River is the south-oriented river located in the figure 4 east half. Baldhill Creek is the southeast-oriented stream joining the south-oriented Sheyenne River near the figure 4 south edge. The Sheyenne River valley is flooded by Lake Ashtabula, which is a reservoir impounded behind Baldhill Dam (located south of the figure 4 map area). The area east of the Sheyenne River is slightly higher than the region west of the Sheyenne River and appears to be more hummocky, suggesting less melt water flood water erosion. In other words, southeast-oriented flood water eroded the surface west of the Sheyenne River, but did not erode the surface (at least as intensively) east of the Sheyenne River. Flood waters were coming from what is today the James River drainage basin, although to the northwest the Sheyenne River headwaters loop around the James River headwaters, meaning the flood waters flowed across what is today the James River drainage basin (see Sheyenne River-James River drainage divide area essay found under James River on sidebar category list). The Sheyenne River valley was probably eroded headward as an ice-walled and bedrock-floored valley into a decaying ice sheet. Flood waters probably removed much of the ice west of the Sheyenne River while ice remained east of the Sheyenne River. Uneven melting of the ice sheet remnants resulted in deposition of debris contained within and that accumulated on top of those ice sheet remnants, which is the reason for the hummocky topography east of the Sheyenne River. Much of the finer grained debris was probably removed west of the Sheyenne River, although flood waters may have deposited more materials in that region than found in the region to the east. The Baldhill Creek valley probably eroded headward to capture southeast-oriented flood flow moving to what was then the newly eroded south-oriented Sheyenne River valley. Evidence further downstream (see figures 8 and 10) shows the south-oriented flood flow moving along the present day south-oriented Sheyenne River alignment was captured and diverted east and northeast. That capture probably was responsible for headward erosion of the present day deep Sheyenne River valley (and Baldhill Creek valley), although flood waters were moving southeast and south across the figure 4 map area prior to headward erosion of the present day valleys.

James River-Sevenmile Coulee north drainage divide area

Figure 5: James River-Sevenmile Coulee north drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 illustrates the James River-Sevenmile Coulee drainage divide area west and slightly south of the figure 4 map area. The south-oriented James River is located along the figure 5 west edge (southwest quadrant). The James River valley in figure 5 is flooded by Jamestown Reservoir. South-southeast oriented Sevenmile Coulee is located in the figure 5 south center edge area and flows to the figure 5 south edge. Note how Sevenmile Coulee is linked by multiple valleys with Spiritwood Lake and how southeast and southwest-oriented through valleys provide evidence the south-oriented Sevenmile Coulee valley once collected south-oriented flood water from a large region to the north. The figure 5 region is also marked by numerous small lakes, suggesting the possibility flood waters deposited flood carried debris around remnant ice masses. Lakes in the valley complex probably have a different origin and may be related to the fact the valleys were eroded headward as ice-walled and bedrock-floored valleys into decaying ice sheet remnants. Depending on valley widths and debris contained within (or accumulated on top of) those decaying ice sheet remnants ice-carried debris partially filled and blocked what became inactive melt water flood valleys following capture of the melt water flood flow further to the north and west. Note also how the south-oriented James River valley is linked to the southeast-oriented valley system leading to Blue Lake. This linkage is evidence the James River valley and the Sevenmile Coulee valley (and the various tributary valleys) developed as channels in a south-oriented anastomosing channel complex, which provides evidence of a large south-oriented melt water flood. As already stated the melt water flood probably occurred at a time when the figure 5 map area was still covered with ice sheet remnants and the various valleys eroded headward as ice-walled and bedrock-floored valleys, although initially they were ice-walled and ice-floored valleys. The James River valley, eroded the deepest valley, probably because it was located west of the Sevenmile Coulee valley and could capture the southeast-oriented flood flow. As a result the James River valley beheaded flood flow moving to Sevenmile Coulee, and unlike the Sevenmile Coulee valley system, was able to develop a significant upstream drainage basin.

James River-Sevenmile Coulee south drainage divide area

Figure 6: James River-Sevenmile Coulee south drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 illustrates the James River-Sevenmile Coulee drainage divide area south of the figure 5 map area. The south-oriented James River is located along the figure 6 west edge area (north of Jamestown) and the valley is flooded by Jamestown Reservoir. Southeast-oriented Pipestem Creek joins the James River at Jamestown. At Jamestown the James River turns to flow southeast to figure 6 south center edge. South-southeast oriented Sevenmile Coulee flows from the figure 6 north center edge area into Spiritwood Township and then turns to flow south-southwest to join the James River near the figure 6 south center edge. Note in Spiritwood Township, where Sevenmile Coulee turns from being south-southeast oriented to being south-southwest oriented a north-northwest oriented tributary joins Sevenmile Coulee as a barbed tributary. That north-northwest oriented tributary flows in a continuation of the south-southeast oriented Sevenmile Coulee valley and has southeast oriented headwaters in the figure 6 southeast quadrant. Note how the various valleys in figure 6 are components of what was once a large south-oriented anastomosing channel complex. For example, a continuation of the south-southeast oriented Sevenmile Creek valley is found south of the elbow of capture where the tributary turns from flowing southwest to flowing north-northwest. The “Y”-shaped valley complex at that tributary elbow of capture originated when the present day south-southwest oriented Sevenmile Coulee valley beheaded south-southeast oriented flood flow moving in the tributary valley. Flood waters on the north-northwest end of the beheaded flood flow route reversed flow direction to create the present-day north-northwest oriented tributary valley. This anastomosing channel complex provides evidence southeast and south-oriented flood waters once moved across the figure 6 map area, probably at a time when the figure 6 map area was still covered with ice sheet remnants. The anastomosing channel complex probably was initiated as an intertwined complex of  south-oriented ice-walled and ice-floored valleys, but in time the channels eroded deep enough to become ice-walled and bedrock-floored valleys. Uneven melting of ice sheet remnants was probably responsible  for at least some of the figure 6 small lakes.

Sheyenne River-Bear Creek drainage divide area near Kathryn

Figure 7: Sheyenne River-Bear Creek drainage divide area near Kathryn. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 illustrates the Sheyenne River-Bear Creek drainage divide area near Kathryn, North Dakota and is located south of figure 4 and southeast of figure 6. The Sheyenne River is located in the meandering valley found in the figure 7 east half. Bear Creek originates near Hastings in the figure 7 north center edge area and flows southeast and south-southeast to the figure 7 south edge. While Bear Creek appears to headed toward the Sheyenne River valley, Bear Creek is in fact a James River tributary. Note how east of Hastings two parallel through valleys link the east-oriented Spring Creek valley with the south-oriented Bear Creek valley. These through valleys (as well as through valleys linking Bear Creek headwaters with Spring Creek northwest of Hasting (and not seen on figure 7) provide evidence headward erosion of the east-oriented Spring Creek valley beheaded south-oriented flood flow routes to the Bear Creek valley (and to the south-oriented James River valley). Also note the much larger through valley in the Little Yellowstone Park area linking the south-oriented Sheyenne River valley with the south-oriented Bear Creek valley. This much larger through valley provides evidence large volumes of flood water once moved from the Sheyenne River to the south-oriented Bear Creek and James River valleys. What is remarkable about these through valleys is they cross the North American north-south continental drainage divide. Water in the Sheyenne River eventually reaches Hudson Bay. Water in Bear Creek eventually reaches the Gulf of Mexico. These through valleys are providing evidence the present day James River and Sheyenne River valleys eroded headward along channels in what was once an immense and ever-changing south-oriented anastomosing channel complex. Headward erosion of the deep Sheyenne River valley and its tributary Spring Creek valley in this figure 7 map area beheaded south-oriented flood flow moving to the James River valley further to the south. However, remember in figure 3, we saw evidence headward erosion of the James River valley had beheaded southeast oriented flood flow moving to the Baldhill Creek and Sheyenne River valleys. What has happened here is an immense southeast and south- oriented melt water flood (probably flowing in an Ice-walled and bedrock-floored valley) was partially captured, with its east half diverted to flow north, while the west half continued to flow south.

Bear Creek-Sheyenne River drainage divide area west of Lisbon

Figure 8: Bear Creek-Sheyenne River drainage divide area west of Lisbon. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 8 uses reduced size maps to illustrate the Bear Creek-Sheyenne River drainage divide area west of Lisbon, North Dakota and includes overlap areas with figure 7. Note how the Sheyenne River flows south from the figure 8 north edge and then turns to flow southeast to the figure 8 east edge (southeast corner area). What is happening is the Sheyenne River is beginning to make a giant U-turn (see figure 10 below) and flow in a northeast direction to join the north-oriented Red River. As figure 8 illustrates there are multiple south oriented through valleys extending south from where the Sheyenne River begins to turn from being south oriented to being southeast oriented. The south-oriented Bear Creek valley located in the figure 8 center is the most prominent south-oriented valley, although another south-oriented through valley is located in Hanson Township to the east of the Bear Creek valley. These and other through valleys provide evidence headward erosion of the deep Sheyenne River valley beheaded multiple south-oriented flood flow routes and diverted the flood waters northeast to the Red River valley. How could an immense south-oriented melt water flood be captured and diverted to flow north? The south-oriented flood was flowing in an immense southeast and south-oriented ice-walled and bedrock-floored valley that had been sliced by into the surface of a rapidly melting thick North American ice sheet. Further east, another immense south- and southeast-oriented ice-walled and bedrock-floored valley was located along the present day Red River-Minnesota River alignment. The two ice-walled and bedrock-floored valleys intersected in southeast North Dakota, although further to the south they diverged with the eastern valley heading southeast and the western valley heading south. As the ice-walled and bedrock-floored valleys and their tributary valleys eroded headward into the rapidly melting thick ice sheet they chopped the ice sheet up into a number of smaller detached ice sheets. Flood flow in these valleys was south-oriented until headward erosion of east and north-oriented ice-walled and bedrock-floored valleys  began to intersect with the south-oriented Red River-Minnesota River melt water flood flow valley. Those intersections provided shorter routes to the ocean and reversed flood flow which had been moving south in the (Red River valley alignment) ice-walled and bedrock-floored valley. At first flood waters probably flowed north and then east to the present day Great Lakes area, but later flood waters flowed north to the present day Hudson Bay area. The eastern half of the south-oriented melt water flood flow in the figure 8 map area was captured and diverted north when flood flow in the Red River valley reversed direction to flow north.

James River-Bear Creek drainage divide area near La Moure

Figure 9: James River-Bear Creek drainage divide area near La Moure. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 9 illustrates the James River-Bear Creek drainage divide area near La Moure and is located south and east of figure 6 and south and west of figure 8. The James River is located in the figure 9 west half and flows southeast in a large valley from the figure 9 northwest corner to the figure 9 south edge. Bear Creek flows south near the figure 9 east edge and joins the southeast oriented James River south of the figure 9 map area. Figure 9 provides evidence the south-oriented Bear Creek valley was initiated by south-oriented flood flow moving from the present day Sheyenne River drainage basin to the present day James River drainage basin. Note how the James River valley in figure 9 is wider than further to the north. Also, note evidence of glacial moraines covering the figure 9 map area. This glacial moraine evidence suggests there still was ice present in the figure 9 map area as the James River valley eroded headward in what was probably an ice-walled and bedrock floored valley. The James River, unlike the Sheyenne River, continues to flow southeast and south and eventually joins the southeast-oriented Missouri River in southeastern South Dakota. The James River and its tributaries provide evidence the south-oriented melt water flood flow further to the north was only partially captured by headward erosion of the deep Sheyenne River valley seen in figure 8 (and also in figure 10 below). There are probably two reasons why the immense south-oriented flood was only partially captured. First, the south-oriented flood was moving in what was probably a large complex of south-oriented intertwined ice-walled and ice-floored (and bedrock-floored) valleys. Headward erosion of the deeper north-oriented Sheyenne River valley was able to capture flood flow from the eastern half of the anastomosing channel complex, while flood waters continued to move south in the western half of the anastomosing channel complex. Second, flood waters were coming from two different source areas further to the northwest. These different source areas are discussed in the Sheyenne River-James River drainage divide area essay. In brief one source area was a large southeast-oriented ice-walled and bedrock-floored valley passing through what is today the Souris River drainage basin in north central North Dakota. A major flood flow reversal in north central North Dakota beheaded southeast-oriented flood flow in that ice-walled and bedrock-floored valley at about the same time as the deep Sheyenne River valley eroded headward to capture that flow. The other source area was ice marginal melt water floods flowing east and northeast into the deep “hole”, where the thick ice sheet had been located. These ice-marginal floods eroded ice-walled and bedrock-floored valleys across the detached ice sheet margin to reach the lower elevation southeast- and south-oriented lowland into which the present day James River and Sheyenne River valleys have been eroded. Sheyenne River valley headward erosion captured flood flow from one of these ice marginal flood flow routes, while James River valley headward erosion captured flood flow from a different, but adjacent ice marginal flood flow route.

Sheyenne River elbow of capture near Lisbon, North Dakota

Figure 10: Sheyenne River elbow of capture near Lisbon, North Dakota. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 10 illustrates the Sheyenne River elbow of capture near Lisbon, North Dakota and is located east of the figure 8 map area and includes overlap areas with figure 8. Note how the Sheyenne River, which further to the north was very much a south-oriented river is turning to become a north-oriented river. As previously mentioned this change in direction resulted when south-oriented flood waters in what was an ice-walled and bedrock-floored valley (located on the present day Red River valley alignment and which had been sliced into a rapidly melting thick ice sheet) were beheaded further to the north and diverted east to the present day Great Lakes area and later north to Hudson Bay. This flood flow reversal occurred because the south-oriented ice-walled and bedrock-floored (and ice-floored) anastomosing valley complex in which the present day south-oriented James and Sheyenne River valleys are located was intertwined in southeast North Dakota with what was probably a similar anastomosing valley complex located along the present day Red River and Minnesota River alignments. When south-oriented flood waters in the present day Red River valley reversed flow direction to flow north, the reversed flood flow was able to capture south-oriented flood flow from the eastern half of the south-oriented anastomosing valley complex further to the west. This capture enabled the deeper Sheyenne River valley to erode north and (north of the James River-Sheyenne River drainage divide area discussed in this essay) to erode west to capture significant amounts of south-oriented flood water. Flood waters probably carried large volumes of sediment, which were deposited when the flood waters reached lower gradient north-oriented slopes (remember, prior to its reversal the Red River valley had been a south-oriented melt water flood flow route). Deposition of flood transported sediments probably accounts for the shallower north-oriented Sheyenne River valley (compared with the south-oriented Sheyenne River valley to the west and northwest).

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.