A geomorphic history based on topographic map evidence

Beaver Creek is a Little Missouri River tributary originating in eastern Montana and flowing into western North Dakota where it joins the Little Missouri River. Although detailed topographic maps of the Beaver Creek drainage basin have been available for fifty years detailed topographic map evidence has not previously been used to interpret Beaver Creek drainage basin geomorphic history. The interpretation provided here is based entirely on topographic map evidence. Based on map evidence the Beaver Creek drainage basin was eroded during immense flood events, the first of which flowed on a topographic surface at least as high as the highest points in the present-day Beaver Creek drainage basin. Flood erosion ended when headward erosion of the deep Yellowstone River valley captured the southeast-oriented flood flow.

Preface:

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

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore eastern Montana and western North Dakota Beaver Creek drainage basin 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 Beaver Creek landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Beaver Creek location map

Figure 1: Beaver Creek drainage basin location map (select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

Beaver Creek flows north in Montana along the Montana-North Dakota border and then turns northeast to flow into North Dakota and join the Little Missouri River. To the east the Beaver Creek drainage basin is bounded by the Little Missouri River drainage basin and to the west the Beaver Creek drainage basin is bounded by the Yellowstone River drainage basin. Much of the north-oriented Beaver Creek segment flows on an escarpment-surrounded upland topographic surface. Beaver Creek tributaries from the west frequently have a southeast orientation and opposing tributaries to the adjacent Yellowstone River usually have a northwest orientation. Beaver Creek tributaries from the east often have a northwest orientation and opposing tributaries to the adjacent Little Missouri River frequently have a southeast orientation. This aligned drainage pattern is evidence the north-oriented Yellowstone River, Beaver Creek, and Little Missouri River valleys were formed by headward erosion of north-oriented valleys that captured massive floods moving in a southeast direction across the entire region. Headward erosion of the north-oriented Little Missouri River valley would have occurred first and would have beheaded flood flow routes across southwest North Dakota. Headward erosion of the Beaver Creek valley occurred next and captured southeast-oriented flood flow moving to the newly eroded Little Missouri River valley. Yellowstone River valley erosion occurred last and captured southeast-oriented flood flow to the newly formed Beaver Creek drainage basin (and further south to the newly formed Little Missouri River valley).

Escarpment-surrounded Beaver Creek headwaters

Figure 2: Escarpment-surrounded Beaver Creek headwaters. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 2 illustrates the Beaver Creek headwaters region located on an escarpment-surrounded upland surface north of Baker, Montana. To the southeast the Beaver Creek upland is bounded by the north-northeast oriented Little Missouri River valley west wall. Drainage down this escarpment to the Little Missouri River is predominantly in a southeast direction. West of the Beaver Creek upland is an escarpment leading to the deep northeast-oriented Yellowstone River valley. Drainage down this western escarpment to the Yellowstone River is predominantly in a northwest direction. This aligned drainage on both sides of the Beaver Creek upland surface is evidence the deep Little Missouri River and Yellowstone River valleys and the much shallower Beaver Creek valley were all eroded headward across southeast-oriented flood water that was moving over the entire region. South of the Beaver Creek upland is a broad northwest to southeast oriented through valley drained to the northwest of Baker, Montana by Sandstone Creek, a northwest-oriented Yellowstone River tributary and to the southeast of Baker by southeast-oriented Waterhole Creek flowing to northeast-oriented Little Beaver Creek, which flows to the Little Missouri River at Marmarth, North Dakota. This through valley was carved as a major southeast-oriented flood flow route to the deep Little Missouri River valley that captured southeast-oriented flood flow to the Beaver Creek upland surface and that was in turn beheaded by headward erosion of the deep Yellowstone River valley. Beheading of this southeast-oriented flood flow route caused a reversal of flood flow to create northwest-oriented Yellowstone River tributaries.

Detailed map of Beaver Creek headwaters

Figure 3: Detailed map of Beaver Creek headwaters. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Beaver Creek begins near the south end of the Beaver Creek upland and flows in a shallow valley in a northeast direction paralleling the upland’s southeast escarpment (northwest wall of deep northeast-oriented Little Missouri River valley).  Note southeast-oriented tributaries to the northeast-oriented Beaver Creek segment and southeast-oriented Little Missouri River tributaries flowing down the Beaver Creek upland southeast escarpment wall. Also note through valleys at heads of those southeast-oriented Little Missouri River tributaries indicating the northeast-oriented Beaver Creek valley eroded southwest across multiple southeast-oriented flow routes and beheaded flow moving to the Little Missouri River valley. A pronounced Beaver Creek elbow of capture can be seen near the Montana-North Dakota state line where northeast oriented Beaver Creek abruptly turns northwest. Note the south-oriented tributary valley (or pre-capture valley) that joins Beaver Creek at this elbow of capture. The northwest oriented Beaver Creek segment is a reversal of flow on what was a southeast-oriented flood flow route. The East Fork of Beaver Creek flows in a northeast direction across the figure 3 northwest corner and joins Beaver Creek north of figure 3. Both the northeast-oriented Beaver Creek segment and the East Fork of Beaver Creek originated as northeast-oriented drainage basins that were beheaded when the deep northwest to southeast-oriented through valley immediately south of the Beaver Creek upland was carved. The Beaver Creek upland south wall was formed as that southeast-oriented through valley’s northeast wall.

Sandstone Creek-Waterhole Creek drainage divide

Figure 4: Sandstone Creek-Waterhole Creek drainage divide east of Baker, Montana. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

While not in the Beaver Creek drainage basin area the through valley linking Sandstone Creek and other northwest-oriented Yellowstone River tributaries with Waterhole Creek and other southeast-oriented Little Missouri River tributaries played a significant role in Beaver Creek history. Figure 4 illustrates a shallow through valley linking northwest-oriented Sandstone Creek with southeast-oriented Waterhole Creek. Actually the situation is more complex than what figure 4 shows. Several northwest-oriented Yellowstone River tributaries originate in the Baker, Montana area and several southeast-oriented Little Missouri River originate in the same region. Further, the southeast-oriented Little Missouri River tributaries first flow to the northeast-oriented Little Beaver Creek, which joins the Little Missouri River at Marmarth, North Dakota. Apparently when the deep Little Missouri River valley eroded southwest to the Marmarth region deep southeast-oriented valleys eroded in a northwest direction to capture southeast-oriented floodwaters. Flood flow to these deep southeast-oriented valleys was subsequently captured by headward erosion of the deeper northeast-oriented Yellowstone River valley. Flood flow on beheaded southeast-oriented flood flow routes was reversed (and fed by flow from yet to be beheaded southeast-oriented flow routes) so as to create in sequence the present-day northwest-oriented Yellowstone River tributaries. What must have been an immense surge of flood water around the south end of the present-day Beaver Creek upland surface played a key role in creating the escarpments surrounding that upland surface.

Beaver Creek along the Beaver Creek upland surface west escarpment rim

Figure 5: Beaver Creek along the Beaver Creek upland surface west escarpment rim. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

From its elbow of capture, where the northeast-oriented Beaver Creek turns to flow northwest, Beaver Creek flows northwest across the Beaver Creek upland surface almost until it reaches the west escarpment rim. Figure 5 illustrates the region where Beaver Creek is flowing in a northwest direction and two interesting northeast-oriented tributaries. The southernmost is the Fork of Beaver Creek, which flows from a well-defined notch in the west escarpment rim in a northeast direction to join northwest-oriented Beaver Creek.  Note the southeast and northwest-oriented Fork of Beaver Creek tributaries. Also note how northwest-oriented Yellowstone River tributaries begin at the same escarpment rim notch, which appears at the location of headcut like indentation in the west escarpment wall. This evidence suggests the deeper northwest-oriented Yellowstone River tributary beheaded the shallower northeast-oriented Fork of Beaver Creek valley and perhaps caused a flood flow reversal, with north-oriented Beaver Creek flood waters spilling to the southwest to the developing northwest-oriented Yellowstone River valley. This flow reversal may have ended when Yellowstone River valley erosion to the west beheaded all flood flow to the Beaver Creek upland surface. Spring Creek flows northeast from a similar notch in the escarpment rim wall and may have had a similar history. A northwest-oriented Yellowstone River tributary also begins at the Spring Creek escarpment rim notch and for a time may have been fed by reversed flood water.

Beaver Creek-Little Missouri River drainage divide near Golva

Figure 6: Beaver Creek-Little Missouri River drainage divide near Golva. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

The Beaver Creek upland surface east escarpment becomes less pronounced to the north, but is still a prominent feature in the Golva, North Dakota area. The east escarpment in figure 6 is a south to north-oriented topographic feature and serves as the Beaver Creek-Little Missouri River drainage divide. Northwest-oriented Beaver Creek tributaries begin at the escarpment rim and generally flow in a northwest direction. These tributaries originated as southeast-oriented flood flow routes that Beaver Creek valley headward erosion beheaded. Because the newly eroded Beaver Creek valley was deeper flood waters on the northwest ends of the beheaded southeast-oriented flood flow routes reversed direction and flowed back to the new Beaver Creek valley. This reversal of flood flow, perhaps aided by floodwaters from yet to be beheaded flood flow routes, eroded the present-day northwest oriented Beaver Creek tributaries. The northwest to southeast-oriented aligned drainage pattern east of the escarpment has been somewhat obscured by several parallel Little Missouri River tributaries that have eroded east and east-northeast oriented valleys to define the Beaver Creek upland surface east escarpment wall. These east- and northeast-oriented Little Missouri River tributary valleys probably were eroding the escarpment wall southward at the same time the new Beaver Creek valley was beheading the southeast-oriented flood flow routes. Note valleys crossing the escarpment rim where flood waters moved in a southeast-oriented direction to the Little Missouri River tributary valleys. The lack of deep valleys suggests the southeast-oriented flood flow after actively eroding the valleys to the present-day escarpment location ceased rather abruptly, suggesting the Beaver Creek valley also formed rapidly.

North-oriented Beaver Creek and west Beaver Creek upland escarpment rim

Figure 7: North-oriented Beaver Creek and west Beaver Creek upland escarpment rim. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Beaver Creek flows north with some jogs to the northeast along the Beaver Creek upland surface west escarpment rim. For most of its course, as can be seen in figure 7, Beaver Creek tributaries from the west are short, begin at escarpment rim notches, flow in well-defined southeast-oriented valleys and join Beaver Creek as barbed tributaries. At the escarpment rim notches opposing these southeast-oriented Beaver Creek tributaries are at the heads of northwest oriented Yellowstone River tributaries. Beaver Creek tributaries from the east are generally longer and flow in a northwest direction. This aligned drainage pattern is evidence the shallow north-oriented Beaver Creek valley eroded across multiple northwest to southeast-oriented flood water routes flowing to what was probably the developing deep north-oriented Little Missouri River valley. It is possible the northwest and north-oriented Beaver Creek segments originally developed as south and southeast-oriented flood flow routes and then were captured and reversed by headward erosion of the deeper northeast-oriented Beaver Creek valley (from the deep Little Missouri River valley). In any case development of the Beaver Creek valley beheaded southeast-oriented flood flow routes causing reversals of flood flow on the northwest ends of those beheaded flow routes to create present-day northwest-oriented Beaver Creek tributaries. Headward erosion of the deep Yellowstone River valley subsequently eroded southwest to behead southeast-moving flood waters to the Beaver Creek drainage basin and to cause flow reversals producing the present-day high-gradient northwest-oriented Yellowstone River tributaries.

Anastomosing channel complex along the Beaver Creek-Little Missouri River drainage divide

Figure 8: Anastomosing channel complex along Beaver Creek-Little Missouri River drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 8 illustrates an anastomosing channel complex located on the Beaver Creek-Little Missouri River drainage divide just east of Beach, North Dakota. Little Beaver Creek is a north-oriented Beaver Creek tributary. Note how Little Beaver Creek begins as a northwest-oriented stream and makes a significant northwest-oriented jog. Headwaters of northwest-oriented Yates Creek can also be seen in the figure 8 (southwest corner). East-oriented Andrews Creek flows to the Little Missouri River (figure 8 northeast corner) while the North and South Forks of Garner Creek can also be seen (southeast corner). Note how channels are cut around the buttes. This is a classic anastomosing channel complex pattern. Further supporting the anastomosing channel complex interpretation, while not visible on the topographic maps, is the presence of coarse-grained alluvium on the channel floors. The alluvium includes rock types derived from the Yellowstone River drainage basin. The fact the anastomosing channel complex is carved around the buttes indicates the east and southeast-oriented floodwaters first flowed on a topographic surface at least as high as the present-day butte tops. Sentinel Butte is one of the highest buttes in North Dakota today. The volume of sediment that had to be removed to produce the present-day anastomosing complex and the surrounding Beaver Creek upland topographic surface (not to mention the deep Little Missouri and Yellowstone River valleys or the Knife, Heart and Cannonball River drainage basins to the east) suggests the regional landscape was carved by an immense flood far bigger than any flood yet described in the geologic literature.

Beaver Creek-Little Missouri River confluence

Figure 9: Beaver Creek-Little Missouri River confluence. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 9 illustrates the Beaver Creek-Little Missouri River confluence area. Compare the Beaver Creek valley depth in figure 9 with the Beaver Creek valley depth in figures 5 and 7. Unlike the southern Beaver Creek segments the northeast-oriented Beaver Creek segment leading to the deep Little Missouri River valley has carved a deep valley. This northeast-oriented Beaver Creek segment crosses a region with a pronounced aligned drainage pattern where southeast-oriented tributaries flow in deep valleys from the northwest and shorter northwest-oriented tributaries flow in from the southeast. The deep northeast-oriented Beaver Creek valley appears to have eroded headward across an immense southeast-oriented flood, although deep Beaver Creek valley erosion diverted flood flow to the northeast. Southeast-oriented Beaver Creek tributaries flowing from the Beaver Creek-Yellowstone River drainage divide are much higher gradient than the opposing northwest-oriented Yellowstone River tributaries. This asymmetric drainage suggests the northwest-oriented Yellowstone River tributary valleys were eroded by reversals of flood flow when the deep Yellowstone River valley beheaded southeast-oriented flood flow routes leading to the Beaver Creek drainage basin. Little Missouri River tributaries beginning at the Beaver Creek-Little Missouri River drainage divide are northeast-oriented, although a few begin in southeast-oriented valleys. This northeast-orientation probably resulted from diversions of the southeast-oriented flood flow to northeast-oriented flood flow due to the deep Little Missouri valley and adjacent deep Beaver Creek valley.

Beaver Creek-Yellowstone River drainage divide

Figure 10: Beaver Creek-Yellowstone River drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 10 provides a detailed look at a small Beaver Creek-Yellowstone River drainage divide area shown in the northwest quadrant of figure 9. Horse Creek is a high gradient southeast-oriented Beaver tributary. South Fork Smith Creek is a lower gradient northwest-oriented Yellowstone River tributary. Note the multiple through valleys linking headwaters of the various Beaver Creek and Yellowstone River tributaries and the orientations of those streams. For example, Horse Creek headwaters begin with a northeast orientation and then turn to flow southeast. These Horse Creek elbows of capture probably resulted because the deep southeast-oriented Horse Creek valley was eroding northwest at the same time the deep Yellowstone River valley erosion was beheading southeast-oriented flood flow on the South Fork Smith Creek route. While flood flow on the beheaded South Fork Smith Creek route was being reversed, southeast-oriented flood flow just to the southwest continued and some of that adjacent southeast-oriented flood flow was diverted in a northeast direction to the reversed northwest-oriented South Fork Smith Creek and then was captured by deep southeast-oriented Horse Creek valley headward erosion. While more detailed map analysis is needed drainage divides like the Beaver Creek-Yellowstone River drainage divide were formed as both northeast-oriented valleys eroded headward at approximately the same time. Further, flow reversals on beheaded flood flow routes were supplied with large volumes of flood water from adjacent yet to be beheaded flood flow routes and as a result had sufficient water to erode deep valleys.

Summary of Beaver Creek drainage basin evolution

• The earliest Beaver Creek drainage basin history event determinable from topographic map evidence was a topographic surface at least as high as the present-day Beaver Creek-Little Missouri River drainage divide butte tops. There is abundant topographic map evidence throughout the Beaver Creek drainage basin to suggest immense southeast-oriented floods carved the regional landscape. Evidence, especially in the form of Beaver Creek drainage basin elbows of capture and the north and northeast-oriented Beaver Creek valley, suggests southeast-oriented flood water was captured and diverted to flow north and northeast. A northwest to southeast oriented drainage alignment prevails across the region. Numerous elbows of capture provide evidence of a rapidly evolving drainage system characteristic of a large-scale flood event. Numerous through valleys link the Beaver Creek drainage basin with adjacent drainage basins and also cross drainage divides between Beaver Creek tributaries. A well-defined anastomosing channel complex can be observed in the Beach, North Dakota area and larger regional valleys can be viewed in bigger perspective as part of a large-scale anastomosing channel complex. Asymmetric drainage divides and erosion-produced escarpments surrounding the Beaver Creek upland topographic surface provide further evidence of massive flood erosion.

• Stripping of regional rock layers to leave the buttes as isolated monadnocks probably was done when immense southeast-oriented floods eroded adjacent broad and deep southeast-oriented valleys in a northwest direction across the region. While much stripping probably occurred prior to erosion events for which there is good evidence, initial stripping was probably just an earlier stage in what were a progressive and continuing series of flood caused erosion events. Earlier flood erosion events probably were similar to later flood caused erosion events for which there is good topographic map evidence, although most earlier flood erosion event evidence has been eroded away.

• Topographic map evidence indicates the present-day Beaver Creek drainage basin erosion began when the north-oriented Little Missouri River valley eroded south to capture southeast-oriented flood waters coming from the west and northwest. At the same time the Beaver Creek valley, a northeast-oriented Little Missouri River tributary, eroded to the southwest and south, although with enough delay that it could capture southeast-oriented flood waters moving to the newly eroded deep Little Missouri River valley. The deep Yellowstone River valley also eroded southwest at approximately the same time, although with enough delay that it could behead and capture southeast-oriented flood waters moving to the newly formed Beaver Creek drainage basin.

• Prior to being captured by the deep northeast-oriented Yellowstone River valley, southeast-oriented flood waters south of the present-day Beaver Creek upland were captured by the northeast-oriented Little Missouri River-Little Beaver Creek valley. These captured southeast-oriented flood waters were responsible for eroding the Beaver Creek upland south wall (probably as the north wall of a large east-oriented valley formed when the deep Little Missouri River valley tributary was eroded northwest along the present-day Waterhole Creek-Pennel Creek alignment). Flood waters also lowered the Yellowstone River-Little Missouri River drainage divide south of the Beaver Creek upland and carved numerous other northwest to southeast oriented through valleys across that drainage divide. Escarpments surrounding the Beaver Creek upland provide a measure of the magnitude of erosion accomplished when the deep northeast-oriented Little Missouri River valley  and later the deep northeast-oriented Yellowstone River valley captured the southeast-oriented flood waters ending the southeast-oriented flood flow across the present-day southwest North Dakota and northwest South Dakota.

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 the detailed 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 were created using National Geographic 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.