A geomorphic history based on topographic map evidence

The Redwater River-Yellowstone River drainage divide area is located in eastern Montana, USA and is actually the drainage divide area between the Redwater River, which is a northeast and north-oriented Missouri River tributary, and the northeast oriented Yellowstone River. Although detailed topographic maps of the Redwater River-Yellowstone River drainage divide area have been available for more than fifty years detailed map evidence has not previously been used to interpret the region’s geomorphic history. The interpretation provided here is based entirely on topographic map evidence. The Redwater River-Yellowstone River drainage divide area is interpreted to have been eroded during immense southeast-oriented flood events, the first of which flowed on a topographic surface at least as high as the highest points in the present-day drainage divide area. Flood erosion across the drainage divide ended when headward erosion of the deep northeast and north-oriented Redwater River valley captured all southeast-oriented flood flow.

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore eastern Montana Redwater River-Yellowstone River drainage divide area landform origins. Map interpretation methods can be used to unravel many geomorphic events leading up to formation of present-day drainage routes and development of other landform features. While each detailed topographic map feature provides detailed evidence to be explained, the solution must be consistent with explanations for adjacent area map evidence as well as solutions to big picture map evidence puzzles. I invite readers to improve upon my solutions or to propose alternate solutions that better explain evidence and are also consistent with adjacent map area and big picture evidence. Readers may do so either by making comments here or by writing and publishing their own essays and then by leaving a link to those essays in a comment here.

• This essay is also exploring a paradigm in which erosional landforms are interpreted as evidence left by immense glacial melt water floods. Implied in that interpretation is the immense floods were derived from a thick North American ice sheet that created a deep “hole” in the North American continent and also melted fast. The previously unexplored paradigm being tested in this and similar essays is a thick North American ice sheet, comparable in thickness to the present day Antarctic ice sheet, occupied approximately the North American region usually recognized to have been glaciated and through its weight and erosive actions created a “deep” North American “hole”, through its weight and deep erosion (and perhaps deposition) along major south-oriented melt water flow routes caused significant crustal warping and tectonic change, through its action of melting fast produced immense floods that flowed across the continent, and through its action of melting fast systematically opened up space in the ice sheet created “hole” so headward erosion of newly developed north-oriented drainage systems captured immense south-oriented melt water floods and diverted immense melt water floods north into space the ice sheet had once occupied.

• If this previously unexplored paradigm is correct the geographic region explored by this essay should contain evidence of immense floods that were captured by headward erosion of new valley systems so as to cause the floods to flow in a different direction. Ability of this previously unexplored paradigm to explain Redwater River-Yellowstone River drainage divide area landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Redwater River-Yellowstone River drainage divide area location map

Figure 1: Redwater River-Yellowstone 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 Redwater River-Yellowstone River drainage divide area location map. The state west of the north-south green border line is Montana. East of the north-south purple border is North Dakota. The Yellowstone River flows from the figure 1 southwest corner to join the east-oriented Missouri River southwest of Williston, North Dakota. Fort Peck Lake is a reservoir flooding the Missouri River valley and today downstream from Fort Peck Dam the Missouri River flows roughly in an east direction across the figure 1 top half. While outside the region considered by this essay in northeast Montana a large valley extends from the Missouri River valley northeast through Medicine Lake and is sometimes considered to be a former Missouri River channel, and it is possible the Redwater River valley was eroded at a time when the Missouri River flowed northeast in that now abandoned northeast oriented valley. The northwest, northeast, and north-oriented Redwater River is located between Fort Peck Lake and the Yellowstone River and joins the Missouri River near Poplar, Montana. Figure 1 illustrates numerous southeast and northwest-oriented Yellowstone River and Redwater River tributaries. This southeast and northwest-orientation of tributary valleys is evidence the northeast-oriented Yellowstone River valley eroded southwest across multiple southeast-oriented flood flow routes, such as might be found in a large-scale flood-formed anastomosing channel complex, and subsequently the Redwater River valley eroded south and southwest across the same anastomosing channel complex. Northwest-oriented tributary valleys were eroded by reversed flood flow on northwest ends of  beheaded flood flow channels. Because channels were anastomosing (meaning they were interconnected) reversed flood flow on beheaded flood flow channels often captured yet to be beheaded southeast-oriented flood flow from flood flow channels further to the southwest. Such captures of yet to be beheaded flood flow often helped erode significant northwest-oriented tributary valleys. Based on the northwest-southeast orientation of tributary streams, landform evidence illustrated here is interpreted in the context of an immense southeast-oriented flood flowing across the entire figure 1 map area and which was systematically captured and diverted further and further to the northeast by headward erosion of deep valleys eroded into a topographic surface at least as high as the figure 1 region highest elevations today. In the figure 1 map region headward erosion of the Yellowstone River valley captured southeast-oriented flood flow and diverted the flood waters northeast, and subsequently headward erosion of the north- and northeast-oriented Redwater River valley captured the same southeast-oriented flood flow and diverted the flood waters still further to the northeast. Detailed maps below provide evidence supporting this interpretation. The O’Fallon Creek-Little Beaver Creek drainage divide area essay and in the Powder River-O’Fallon Creek drainage area essay describe regions located immediately southeast of the southeast end of the Redwater River-Yellowstone River drainage divide area described here (O’Fallon Creek is A Yellowstone River tributary and Little Beaver Creek is a Little Missouri River tributary-essays can be found under appropriate river names on the sidebar category list). A companion essay discusses landform origins in the northeast end of Redwater River-Yellowstone River drainage divide area and can be found under Redwater River on the sidebar category list.

Redwater River-Yellowstone River drainage divide area detailed location map

Figure 2: Redwater River-Yellowstone River drainage divide area detailed location map. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 2 illustrates a somewhat more detailed map of the Redwater River-Yellowstone River drainage divide area discussed here. Dawson and Prairie Counties are located in Montana and west of Dawson County is McCone County. The Redwater River-Yellowstone River drainage divide area discussed here is located primarily southwest of the highway extending southeast from Circle to Forest Park (Glendive). The Yellowstone River flows northeast through Terry, Fallon, Marsh, Hoyt, and Forest Park (Glendive) to the figure 2 east center edge. The Redwater River flows northeast in McCone County through Watkins, Brockway, and Circle at the figure 2 north edge. Figure 2 shows many more southeast-oriented Yellowstone River tributaries and many more northwest-oriented Redwater River tributaries than figure 1. Also, while outside the Redwater River-Yellowstone River drainage divide area there are numerous southeast-oriented Redwater River tributaries and nearly all Yellowstone River tributaries from the east are northwest-oriented. This northwest-southeast drainage alignment is evidence the northeast oriented Yellowstone River valley eroded southwest across an immense southeast-oriented flood to capture the flood waters and to divert the flood waters northeast. Further, the drainage alignment is evidence the northeast and north oriented Redwater River valley eroded south and southwest across the same immense southeast-oriented flood to capture flood waters moving to the newly eroded Yellowstone River valley and to divert the flood waters still further to the northeast and north. The southeast-oriented tributary valleys were eroded by southeast-oriented flood flow moving into the newly eroded and deep Yellowstone and Redwater River valleys. The northwest-oriented tributary valleys were eroded by reversed flood flow on the northwest ends of beheaded southeast-oriented flood flow routes. Because flood waters move in and erode anastomosing (or interconnected) channels reversed flood flow on a beheaded flood flow route could capture flood flow from yet to be beheaded flood flow routes. Such captures of yet to be beheaded flood flow would enable the reversed flood flow routes to erode much deeper and larger northwest-oriented valleys than might otherwise be possible. Northwest-oriented drainage in the figure 2 west center and northwest corner flows to the Missouri River at Fort Peck Lake (see figure 1). The unnamed northwest-oriented stream flowing in the opposite direction of Cherry Creek (which flows southeast through McCloud to join the Yellowstone River near Terry) is Timber Creek and the Timber Creek-Cherry Creek alignment represents the Redwater River-Yellowstone River drainage divide area southeast end.

Redwater River-Yellowstone River drainage divide near Rimroad

Figure 3: Redwater River-Yellowstone River drainage divide near Rimroad. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the Redwater River-Yellowstone River drainage divide area near Rimroad. Southeast-oriented drainage in the figure 3 southeast quadrant flows to the northeast-oriented Yellowstone River. Southeast-oriented Clear Creek flows to the figure 3 south edge (east quarter) while southeast-oriented (and unnamed on figure 3) Upper Sevenmile Creek and southeast-oriented Hay Creek flow to the figure 3 east edge (south half). These southeast-oriented Yellowstone River tributary drainage routes originated as channels in a southeast-oriented anastomosing channel complex that eroded the southeast-oriented erosion surface leading into the northeast-oriented Yellowstone River valley. Northwest-oriented streams in figure 3 are Redwater River tributaries and the northwest-oriented slope leading into the northeast-oriented Redwater River valley was eroded by reversed flood flow on the northwest ends of beheaded southeast-oriented flood flow channels. Southeast-oriented flood flow to what was then the newly eroded and deep Yellowstone River valley eroded the southeast-oriented slope leading into the northeast-oriented Yellowstone River valley prior to the existence of the deep Redwater River valley. The deep northeast-oriented Redwater River valley eroded southwest to capture the southeast-oriented flood flow and to divert the flood waters further to the northeast and north (earlier the deep Yellowstone River valley had eroded southwest to capture southeast-oriented flood flow and to divert the flood waters to the northeast). Beheading of the southeast-oriented flood flow routes occurred in sequence from the northeast to the southwest. Because the flood waters were flowing in anastomosing (or interconnected) channels reversed flood flow often captured flood waters from yet to be beheaded flood flow routes further to the southwest. These captures of flood waters from the southwest and the flood flow reversals eroded the northwest-oriented Redwater River tributary valleys and in the process created the present day asymmetric Redwater River-Yellowstone River drainage divide.

Clear Creek headwaters south of Rimroad

Figure 4: Clear Creek headwaters south of Rimroad. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 4 illustrates headwaters of southeast oriented Clear Creek and other southeast-oriented Yellowstone River tributaries south of Rimroad (figure 4 includes overlap areas with figure 3). Clear Creek flows southeast across the figure 4 center. Northeast of Clear Creek is southeast, east, and southeast-oriented Upper Sevenmile Creek and flowing from Rimroad to follow the highway and to join southeast-oriented Upper Sevenmile Creek is southeast-oriented Hay Creek. The southeast-oriented South Fork of Clear Creek is located to the southwest of Clear Creek. South of Lindsay between Upper Sevenmile Creek and Clear Creek are headwaters of southeast-oriented Timber Creek. Southeast-oriented Timber Creek originates immediately southeast of a somewhat streamlined upland mass located between the Upper Sevenmile Creek valley and the Clear Creek valley. That somewhat streamlined upland mass and other less obvious figure 4 upland masses like it are evidence the southeast-oriented Upper Sevenmile Creek, Timber Creek, and Clear Creek valleys all originated as channels in a southeast-oriented anastomosing channel complex. The ever-changing anastomosing channel complex was being eroded by an immense southeast-oriented flood that was eroding the southeast-oriented erosion surface leading into what was then the newly eroded northeast-oriented Yellowstone River valley. In the example described headward erosion of the deeper Upper Sevenmile Creek channel and the deeper Clear Creek channel captured all southeast-oriented flood flow to the southeast-oriented Timber Creek channel. The deep northeast-oriented Yellowstone River valley had eroded southwest to capture the southeast-oriented flood waters (which had earlier been captured by headward erosion of the Little Missouri River valley) and to the divert the flood waters further to the northeast (than the previous Little Missouri River valley diversion had been). Subsequently headward erosion of the deep northeast-oriented Redwater River valley beheaded southeast-oriented flood flow routes that had been eroding the Yellowstone River valley southeast facing wall. The present day southeast-oriented Yellowstone River tributaries are flowing in what were the deepest southeast-oriented channels at the time flood waters ceased to flow across the Redwater River-Yellowstone River drainage divide.

Redwater River valley northwest slope south of Circle

Figure 5: Redwater River valley northwest slope south of Circle. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 illustrates the Redwater River valley northwest-facing slope south of Circle, Montana and includes overlap areas with figure 3. The northeast-oriented Redwater River flows through Circle and northwest-oriented Redwater River tributaries flow from the asymmetric Redwater River-Yellowstone River drainage divide located in the figure 5 southeast corner. The size of the northeast-oriented Redwater River valley illustrated by figure 5 provides some clues as to the magnitude of the southeast-oriented flood that was captured by as the northeast-oriented Redwater River valley headcut eroded southwest. The Redwater River valley size also provides some clues as to the magnitude of erosion the immense southeast-oriented flood accomplished as flood waters were captured and diverted to the northeast. There are no markers in the present day Redwater River-Yellowstone River drainage divide area to give any clues as to how much erosion southeast-oriented flood waters accomplished prior to being captured by headward erosion of the deep northeast-oriented Yellowstone River valley and subsequently being captured by headward erosion of the deep northeast-oriented Redwater River valley. Southeast-oriented flood waters flowed across the entire present day Redwater River-Yellowstone River drainage divide, which today represents the highest elevations in the region. The source of the flood waters cannot be determined from evidence presented here. However, by using the Missouri River drainage basin landform origins research project essays published on this website it is possible to trace the flood waters headward toward their source. Rapid melting of a thick North American ice sheet located in a deep North American “hole” would be a logical flood water source and would also explain why deep northeast-oriented valleys such as the northeast-oriented Yellowstone River valley and the deep Redwater River valley were eroding southwest to capture southeast-oriented flood waters and to divert the flood waters further and further to the northeast and north (into space in the deep North American “hole” the rapidly melting ice sheet had previously occupied).

Pasture Creek-Brackett Creek drainage divide area

Figure 6: Pasture Creek-Brackett Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 illustrates the Pasture Creek-Brackett Creek drainage divide area along the Redwater River-Yellowstone drainage divide and overlaps with figure 4 map areas. The West Fork of Bad Route Creek flows southeast to the figure 6 southeast corner. Southeast-oriented Brackett Creek is located southwest of the West Fork of Bad Route Creek and flows to the figure 6 south edge. Brackett Creek and Bad Route Creek flow southeast to the northeast-oriented Yellowstone River. Northwest of Brackett Creek headwaters are headwaters of northwest-oriented Pasture Creek, which flows to northwest-oriented Tusler Creek, which in turn flows to the northeast-oriented Redwater River. East of Pasture Creek is northwest-oriented Bearshack Creek and then several other northwest-oriented Tusler Creek tributaries, including the North and South Forks of Tusler Creek. West of Pasture Creek is northwest-oriented Ash Creek, which flows to the northeast Redwater River at Brockway, Montana. Note how on both sides of Redwater River-Yellowstone River drainage divide erosional remnants of slightly higher erosion surfaces provide evidence present day tributary valleys originated as channels in anastomosing channel complexes. The southeast-oriented anastomosing channel complex leading down into the Yellowstone River valley was eroded by southeast-oriented flood water prior to headward erosion of the deep northeast-oriented Redwater River valley. The northwest-oriented channel complex was eroded by reversed flood flow on the northwest ends of beheaded southeast-oriented flood flow channels. Because the flood flow channels were anastomosing (or interconnected) reversed flood flow was able to capture flood waters from yet to be beheaded flood flow routes further to the southwest. The size of the northeast-oriented Redwater River valley provides evidence as to the magnitude of the southeast-oriented flood involved. How much erosion was accomplished by southeast-oriented flood waters prior to headward erosion of the Redwater River valley cannot be determined from figure 6 evidence. Southeast-oriented flood waters originally flowed on a topographic surface at least as high as the highest figure 6 elevations today.

Brackett Creek drainage basin area

Figure 7: Brackett Creek drainage basin area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 illustrates more of the Brackett Creek drainage basin area and includes overlap areas with figure 6 above. The southeast-oriented East, Middle, and West Forks of southeast-oriented Bad Route Creek are located in the figure 7 northeast quadrant. Brackett Creek flows southeast from the figure 7 northwest corner and then turns south to flow to the figure 7 south edge. The southeast-oriented Cedar Creek drainage basin is located in the figure 7 southwest corner, with the south-southeast oriented Cedar Creek being located between southeast-oriented Cedar Creek and southeast-oriented Brackett Creek. Figure 7 further illustrates evidence these southeast-oriented Yellowstone River tributary valleys originated as channels in a southeast-oriented anastomosing channel complex. Note how present day valleys diverge and converge. For example, in the figure 7 northwest quadrant note how headwaters of the East Fork Cedar Creek begin in a southeast-oriented valley and then turn south-southeast. Then continue southeast along the southeast-oriented valley alignment to the southeast-oriented Brackett Creek headwaters. Note the large erosional residual between the southeast-oriented Brackett Creek valley and the south-southeast oriented East Fork Cedar Creek valley and then note that Brackett Creek turns south-southeast to join Cedar Creek south of the figure 7 map area. Also note the south-southeast West Fork Brackett Creek valley that originates almost at the south edge of the southeast-oriented Brackett Creek valley and then flows to join Brackett Creek along the figure 7 south edge. Also note how south and south-southeast oriented Cottonwood Creek in the figure 7 southeast quadrant is linked by through valleys northwest of Diamond G Butte with the southeast-oriented West Fork Bad Route Creek valley. These and many other similar example illustrate the anastomosing pattern of channels eroded into the southeast-sloping erosion surface leading into the northeast-oriented Yellowstone River valley. The anastomosing channels were eroded by southeast-oriented flood waters prior to headward erosion of the deep northeast-oriented Redwater River valley and today reflect flood-eroded anastomosing channel patterns that existed just prior to when Redwater River valley headward erosion beheaded the flood flow.

Southwest end of the Redwater River drainage basin

Figure 8 illustrates the southwest end of the Redwater River drainage basin. North-northwest oriented headwaters of the Redwater River are located just west of Morton Spring (figure 8 north enter). East of Morton Spring is north-northwest oriented Lisk Creek and in the figure 8 northeast quadrant is northwest-oriented Duck Creek. Lisk Creek and Duck Creek are Redwater River tributaries. Southwest of Redwater River headwaters in the figure 8 west center is northwest-oriented Timber Creek, which flows to north-oriented Little Dry Creek at Fort Peck Lake (see figure 1). Southeast of northwest-oriented Timber Creek headwaters are headwaters of southeast-oriented Cherry Creek, which flows to the northeast-oriented Yellowstone River valley. North of Big Sheep Mountain and southeast of northwest-oriented Duck Creek headwaters are headwaters of southeast-oriented Cedar Creek, which also flows to the Yellowstone River. Big Sheep Mountain is the highest point in the region and appears to be an erosional remnant left standing as flood waters eroded anastomosing channels around it. Northwest-oriented Lisk Creek headwaters are located immediately northwest of Big Sheep Mountain and a southeast-oriented Cedar Creek tributary originates at Big Sheep Mountain. The northwest-oriented Lisk Creek headwaters and the southeast-oriented Cedar Creek tributary are better seen in figure 9 below, however the evidence suggests southeast-oriented flood waters crossed the highest Big Sheep Mountain elevations before deeper southeast-oriented channels were eroded on either side of the present day erosional residual. The northwest-oriented Timber Creek-Cherry Creek drainage divide provides evidence the Redwater River valley was eroded southwest just prior to headward erosion of the deep Missouri River valley further to the northwest. Headward erosion of the Missouri River-Big Dry Creek valley was what beheaded southeast-oriented flood flow on the Timber Creek-Cherry Creek flood flow route and until that flood flow route was beheaded flood waters moved southeast along the Timber Creek valley alignment.

Redwater River-Yellowstone River drainage divide at Big Sheep Mountain

Figure 9 illustrates a detailed map of the Redwater River-Yellowstone RIver drainage divide at Big Sheep Mountain. Northwest-oriented drainages flowing to the figure 9 west edge (north half) are headwaters of northwest-oriented Lisk Creek, which flows to the northeast-oriented Redwater River. North-oriented drainage flowing to the figure 9 north edge are headwaters of West Fork of Duck Creek, which also flows to the Redwater River. East and southeast-oriented drainage flowing to the figure 9 east edge is flowing to southeast-oriented Cedar Creek and the northeast-oriented Yellowstone River. South and southeast-oriented drainage flowing to the figure 9 south edge is flowing to southeast-oriented Cherry Creek and the Yellowstone River. Note how valleys have eroded headward into the Big Sheep Mountain erosional residual from all directions indicating flood water once flowed over the Big Sheep Mountain top. Further, note how the Big Sheep Mountain top consists of several high points separated by valleys or saddles in the high ridges. Those valleys were eroded by water and today are through valleys linking the various independent drainage basins. Those through valleys were eroded by flood waters moving across a topographic surface at least as high as the highest Big Sheep Mountain elevations today and that surface has been completely removed by flood erosion from the entire surrounding region. There is no evidence to determine how much erosion flood waters accomplished before flowing on that Big Sheep Mountain level topographic surface. However, the amount of erosion accomplished since flood waters flowed on that Big Sheep Mountain topographic surface suggests immense quantities of water had to be involved and those flood waters transported vast amounts of sediments from the region to other locations. While topographic map evidence can be used to identify flood eroded regions, to make minimal estimates of the amount of flood erosion that occurred, to identify certain types of flood deposited sediments, and to identify where flood waters went (and probably carried the eroded materials); topographic map evidence alone cannot be used to identify most flood deposited materials.

Timber Creek (Missouri River)-Cherry Creek (Yellowstone River) drainage divide

Figure 10 illustrates a detailed map of the Timber Creek-Cherry Creek drainage divide area southwest of Big Sheep Mountain and southwest of the Redwater River-Yellowstone River drainage divide southwest end (see figure 8 above for less detailed map of same region). Northwest oriented Timber Creek flows to the figure 10 northwest corner and eventually flows to Big Dry Creek where the Big Dry Creek valley has been flooded by Fort Peck Lake (see figure 1). Unnamed northwest-oriented drainage routes are headwaters of Timber Creek tributaries. The southeast-oriented North Fork of southeast-oriented Cherry Creek is located in the figure 10 southeast corner and other southeast-oriented drainage routes are tributaries to the North Fork Cherry Creek. Had the northeast-oriented Redwater River valley eroded southwest any further southeast-oriented flood flow on this Timber Creek-North Fork Cherry Creek alignment would have been captured and diverted northeast into the Redwater River valley. However, because the Redwater River valley did not erode this far southwest the southeast-oriented flood waters continued to flow over the present day Timber Creek-North Fork Cherry Creek drainage divide until headward erosion of the deep Missouri River valley and its tributary Big Dry Creek valley beheaded the Timber Creek-North Fork Cherry Creek flood flow route. Once beheaded, flood flow on the northwest end of the Timber Creek-North Fork Cherry Creek flood flow reversed flow direction to flow northwest to the newly eroded and deeper Missouri River valley. By reversing flow direction flood waters eroded the northwest-oriented Timber Creek valley and drainage basin and also created the Timber Creek (Missouri River)-Cherry Creek (Yellowstone River) drainage divide. Erosion of the northwest-oriented Timber Creek valley and drainage basin was aided by flood waters from yet to be beheaded flood flow routes further to the southwest. Note how Timber Creek headwaters are north-northwest oriented before turning northwest. That turn in the headwaters direction probably resulted from capture of yet to beheaded flood flow.

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.