A geomorphic history based on topographic map evidence

The Tongue River-Otter Creek drainage divide area is located in southeastern Montana, USA. Although detailed topographic maps of the Tongue River-Otter Creek 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 Tongue River-Otter Creek 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 Tongue River valley captured all 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 southeastern Montana Tongue River-Otter Creek 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 Tongue River-Otter Creek drainage divide area landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Tongue River-Otter Creek drainage divide area location map

Figure 1: Tongue River-Otter Creek 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 Tongue River-Pumpkin Creek drainage divide area location map and illustrates a region in southeastern Montana and northern Wyoming. The state of Montana is located in figure 1 north of the green border line and the state of Wyoming is south of the purple boundary line. The Yellowstone River flows in a northeast direction from Billings to Miles City, Montana. The Tongue River flows northeast from southwest of Sheridan, Wyoming into Montana and then south of Miles City, Montana turns northwest to join the northeast oriented Yellowstone River as a barbed tributary. Otter Creek originates southeast of Otter, Montana and flows north and northwest to join the Tongue River at Ashland, Montana. Landform evidence illustrated in this essay 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 northeast oriented Powder River valley captured the southeast-oriented flood flow and diverted the flood waters north to the northeast oriented Yellowstone River valley (located north of the figure 1). Headward erosion of the deep northeast oriented Yellowstone River and the northeast- and northwest-oriented Tongue River-Pumpkin Creek valley next captured the southeast-oriented flood flow. Soon thereafter headward erosion of the Tongue River-Otter Creek valley captured southeast-oriented flood to the newly eroded Pumpkin Creek valley and to the Powder River valley (south of the Pumpkin Creek valley). Subsequently headward erosion of the deep Tongue River valley captured southeast-oriented flood flow to the newly eroded Otter Creek valley and ended flood flow across the Tongue River-Otter Creek drainage divide. The Pumpkin Creek-Mizpah Creek drainage divide area essay, the Mizpah Creek-Powder River drainage divide area essay, the Powder River-Little Powder River drainage divide area essay describe regions northeast and/or southeast of the area discussed here and can be found under appropriate river names on the sidebar category list (where Pumpkin Creek is a Tongue River tributary and Mizpah Creek is a Powder River tributary) . The Yellowstone River-Tongue River drainage divide area essay describe the region located west and north of the Tongue River-Otter Creek drainage divide area discussed here.

Tongue River-Otter Creek drainage divide area detailed location map

Figure 2: Tongue River-Otter Creek 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 Tongue River-Otter Creek drainage divide area discussed here. Big Horn and Powder River Counties are located in Montana. Sheridan County is located in Wyoming. The Tongue River-Otter Creek drainage divide area discussed here is located primarily in southeast Big Horn County and southwest Powder River County. The Tongue River flows northeast from the figure 2 southwest corner through Ranchester, Wyoming to Tongue River Reservoir (near Decker, Montana) and then northeast to Birney and Ashland, Montana before turning north to flow to the figure 2 north edge. The Powder River flows from the figure 2 south center edge northeast into Powder River County, Montana and then to the figure 2 east edge. Otter Creek originates southeast of Otter, Montana, near where the northeast-oriented Powder River crosses the Wyoming-Montana state line and flows northwest to near Otter where it turns north to flow to the Tongue River at Ashland Montana. Figure 2 shows numerous southeast oriented Tongue River tributaries, southeast oriented and northwest oriented Powder River tributaries, and some southeast and northwest oriented Otter Creek tributaries. This northwest-southeast drainage alignment is evidence the northwest- and north-oriented Otter Creek valley eroded south across an immense southeast-oriented flood to capture flood waters and to divert flood waters north. Further, the drainage alignment is evidence the northeast-oriented Tongue River valley subsequently eroded southwest to capture the same southeast-oriented flood flow. The southeast-oriented tributary valleys were eroded by southeast-oriented flood flow moving into the newly eroded and deep Otter Creek and Tongue 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 could enable the reversed flood flow routes to erode much deeper and larger northwest-oriented valleys than might otherwise be possible. Often evidence for such flow reversals and captures can be found on detailed topographic maps. Detailed maps below start at Ashland where Otter Creek joins the Tongue River. Detailed maps first illustrate drainage divide evidence east of Hanging Woman Creek and second drainage divide evidence west of Hanging Woman Creek.

North end of the Tongue River-Otter Creek drainage divide area

Figure 3: North end of the Tongue River-Otter Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 illustrates the north end of the Tongue River-Otter Creek drainage divide south of Ashland, Montana. The Tongue River flows north-northeast from the figure 3 south edge through the figure 3 center to the figure 3 north edge. Otter Creek flows northwest from the figure 3 southeast corner to join the Tongue River near Ashland. Tongue River tributaries from the west are southeast-oriented and from the east are northwest-oriented. The northwest-southeast orientation of Tongue River tributaries is evidence the deep northeast and north-oriented Tongue River valley eroded headward across multiple southeast-oriented flood flow channels such as might be found in a southeast-oriented anastomosing channel complex. Headward erosion of the deep northeast and north-oriented Tongue River valley captured the southeast-oriented flood flow and diverted the flood waters north to the northeast-oriented Yellowstone River valley. Southeast-oriented Tongue River tributary valleys were eroded by headward erosion from what was then the newly eroded and deep Tongue River valley west wall along southeast-oriented flood flow channels. Northwest-oriented Tongue River tributary valleys were eroded by reversed flood flow on northwest ends of beheaded southeast-oriented flood flow routes. Major northwest-oriented valleys, such as the Otter Creek valley, captured flood flow from yet to be beheaded flood flow routes further to the south and southwest. With aid of captured flood waters it was possible to erode significant northwest-oriented valleys. Otter Creek tributary orientations vary, although Newell Creek in the figure 3 southeast corner is southeast-oriented and the southwest-oriented East Fork (in the figure 3 northeast quadrant) has southeast-oriented tributaries. Remember Otter Creek is northwest-oriented, which means the northwest-oriented Otter Creek valley was eroded by reversed flood flow on the northwest end of a beheaded southeast-oriented flood flow channel and reversed flood flow, which was moving northwest along the Otter Creek alignment, was capturing yet to be beheaded southeast-oriented flood flow. Such captured flood water often moved in a northeast direction to reach the northwest-oriented flood flow channel. Movement of such captured flood flow accounts for the northeast and southwest oriented tributary orientations.

Tongue River-Otter Creek drainage divide in King Creek area

Figure 4: Tongue River-Otter Creek drainage divide in King Creek area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 illustrates the Tongue River-Otter Creek drainage divide area south of the figure 3 map area and includes overlap areas with figure 3. The Tongue River flows northeast from the figure 4 west center edge to the figure 4 north edge. Otter Creek flows north-northwest in the figure 4 east half. Tongue River tributaries are again southeast-oriented from the west and northwest-oriented from the east. King Creek flows northwest from the Black Canyon area in the figure 4 center to join the Tongue River in the figure 4 northwest quadrant. O’Dell Creek flows northwest from the figure 4 south edge center to join the Tongue River in the figure 4 west center. Note how the southwest-oriented East Fork of O’Dell Creek headwaters are linked with the north-oriented headwaters of northwest-oriented King Creek. Southeast-oriented flood flow on the King Creek alignment was beheaded and reversed prior to the beheading and reversing of southeast-oriented flood flow on the O’Dell Creek alignment. Reversed flood flow on the King Creek alignment captured yet to be beheaded southeast-oriented flood flow moving on the O’Dell Creek alignment, and the captured flood water moved northeast (on the present day East Fork alignment) and then north to the northwest-oriented King Creek alignment. When headward erosion of the deep Tongue River valley beheaded and reversed flood flow on the northwest end of the O’Dell Creek alignment, flood flow on the East Fork alignment also reversed flow direction to flow southwest to the newly reversed flood flow on the O’Dell Creek alignment. Otter Creek tributaries again appear to have been initiated by yet to be beheaded flood flow that was captured by reversed flow on the Otter Creek alignment. The Tongue River-Otter Creek drainage divide is a north-south ridge located approximately in the center of figure 4. A close look at the ridge reveals shallow valleys or saddles, which provide evidence flood waters once moved across the ridge along multiple channels to what was then an actively eroding north-northwest and northwest oriented Otter Creek valley. Elevation of the ridge above the present day Otter Creek valley provides a measure of the amount of erosion flood waters accomplished between the time flood flow on the Otter Creek alignment was reversed to what was then the actively eroding deep northeast-oriented Tongue River valley headcut and the time the deep Tongue River valley headcut eroded south beyond the figure 4 map area. There are no markers to indicate how much erosion flood waters accomplished in this region prior to headward erosion of the deep Tongue River valley and its deep tributary Otter Creek valley.

Tongue River-Otter Creek drainage divide in O’Dell Creek area

Figure 5: Tongue River-Otter Creek drainage divide in O’Dell Creek area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Tongue River-Otter Creek drainage divide area south of the figure 4 map area and includes overlap areas with figure 4. The northeast-oriented Tongue River is located in the figure 5 northwest corner. Otter Creek flows north along the figure 5 east edge. The Stockert Branch of O’Dell Creek flows northeast from O’Dell Reservoir to the figure 5 center and then turns northwest to flow as O’Dell Creek to the figure 5 north edge (and to join the Tongue River north of the figure 5 map area). Note how the northeast-oriented Stockert Branch is linked to northwest-oriented headwaters of northwest-oriented Poker Jim Creek, which flows to the northeast-oriented Tongue River and also to south and southwest-oriented tributaries to west-northwest oriented East Fork (of Hanging Woman Creek). Again, southeast-oriented flood flow on the O’Dell Creek valley alignment was beheaded and reversed by headward erosion of the deep Tongue River valley before southeast-oriented flood flow on the Poker Jim Creek and the East Fork Hanging Woman Creek alignments. The northeast-oriented Stockert Branch valley was eroded by yet to be beheaded southeast-oriented flood flow on the Poker Jim Creek and East Fork Hanging Woman Creek alignments that was captured by reversed flood flow on the northwest-oriented O’Dell Creek alignment. Headward erosion of the deep Tongue River valley subsequently beheaded and reversed flood flow on the Poker Jim Creek alignment and later beheaded and reversed flood flow on the East Fork Hanging Woman Creek alignment. Again note shallow trough valleys or saddles eroded into the ridge that today serves as the Tongue River-Otter Creek drainage divide. The through valleys are evidence multiple channels of southeast-oriented flood flow were captured and diverted east to what was then an actively eroding north-oriented Otter Creek valley. The through valleys could not have been eroded if the deep northeast-oriented Tongue River valley had been in existence at that time. Flood waters eroded the north-oriented Otter Creek drainage basin before headward erosion of the deep Tongue River valley and its tributary valleys (such as the O’Dell Creek valley) captured the flood flow and diverted the flood waters more directly to the northeast.

Hanging Woman Creek-Otter Creek drainage divide northwest of Otter

Figure 6: Hanging Woman Creek-Otter Creek drainage divide northwest of Otter. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the Hanging Woman Creek-Otter Creek drainage divide area south of the figure 5 map area. Hanging Woman Creek flows north along the figure 6 west edge. Bear Creek flows north and northeast in the figure 6 southeast corner and joins north-oriented Otter Creek just west of the figure 6 map area. Note east-southeast oriented tributaries to Bear Creek and Otter Creek and west-northwest oriented tributaries to Hanging Woman Creek. Also note how headwaters of Bear Creek and Otter Creek tributaries are linked by multiple through valleys with headwaters of Hanging Woman Creek tributaries. The through valleys provide evidence southeast-oriented flood flow moved across the present day Hanging Woman Creek-Otter Creek and Bear Creek drainage divide and eroded multiple southeast-oriented channels such as might be found in a southeast-oriented anastomosing channel complex. Flood waters were moving to what was then the newly eroded north-oriented Bear Creek-Otter Creek valley. Headward erosion of the deep north-oriented Hanging Woman Creek valley subsequently beheaded the southeast-oriented flood flow routes in sequence from north to south. Flood waters on the northwest ends of beheaded flood flow routes reversed flow direction to flow northwest to the newly eroded north-oriented Hanging Woman Creek valley. Because flood waters had been moving southeast in anastomosing (or interconnected) channels reversed flood flow channels frequently captured yet to be beheaded southeast-oriented flood flow from flood flow routes further to the south and southwest. These captures of yet to be beheaded flood flow enabled the reversed flood flow channels to erode significant northwest-oriented valleys. The figure 6 evidence requires that southeast-oriented flood flow originally moved across the figure 6 map area on a topographic surface at least as high as the highest figure 6 elevations today. How much regional erosion flood water accomplished prior to development of that high level topographic surface cannot be determined from figure 6 evidence, although it is possible flood waters lowered the regional surface significantly more than is apparent from figure 6 evidence.

Hanging Woman Creek-Bear Creek drainage divide

Figure 7: Hanging Woman Creek-Bear Creek drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the Hanging Woman Creek-Bear Creek drainage divide area immediately south of the figure 6 map area. Hanging Woman Creek flows north-northwest along the figure 7 west edge. Bear Creek flows northwest into the figure 7 map area and then turns north and north-northwest to flow along the figure 7 east edge. The north-northwest orientation of the Hanging Woman Creek valley and segments of the Bear Creek valley as well as the northwest-orientation of various tributary valleys provide evidence a major flood flow reversal has taken place in this figure 7 map region. Multiple southeast-oriented flood flow routes were eroding southeast-oriented valleys headward from some deeper valley to the southeast and then headward erosion of the deep Tongue River valley beheaded the southeast-oriented flood flow routes and caused a massive flood flow reversal that affected the entire figure 7 map area. However the flood flow reversal first affected the Bear Creek drainage basin with the northeast-oriented Bear Creek tributary valleys eroding southwest to capture southeast-oriented flood flow and to divert that southeast-oriented flood flow northeast and north to the Otter Creek valley and then to the Tongue River valley. Subsequently, as the deep Tongue River valley eroded southwest, the flood flow reversal affected the Hanging Woman Creek drainage basin and was responsible for eroding the north-northwest oriented Hanging Woman Creek valley and its various tributary valleys. Evidence of flood water movement from the Hanging Woman Creek drainage basin to the Bear Creek drainage basin is found in the numerous shallow through valleys linking the two drainage basins. Figure 8 below illustrates where southeast-oriented flood waters were headed prior to being beheaded and reversed.

Otter Creek-Powder River drainage divide area

Figure 8: Otter Creek-Powder River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 8 illustrates the Otter Creek-Powder River drainage divide area immediately east of the figure 7 map area. The Montana-Wyoming state line is the west to east border line located along the figure 8 south edge.  The north-northeast oriented Powder River is located in the figure 8 southeast corner. Northwest-oriented Bear Creek headwaters are located in the figure 8 southeast quadrant (immediately southwest of northwest-oriented Bates Creek, which is a Bear Creek tributary) and flow to the figure 8 west center edge. Note how northwest-oriented Bear Creek and Bates Creek headwaters are linked to southeast-oriented Powder River tributaries. The northwest-oriented Otter Creek drainage basin is located northeast of Bates Creek drainage basin and drains to the figure 8 north edge (west half). Note the southeast-oriented Powder River tributaries, which provide evidence the deep Powder River valley eroded south-southwest across multiple southeast-oriented flood flow routes. Also note the Powder River tributaries are short, which provides evidence the southeast-oriented flood flow to what was then the newly eroded Powder River valley did not have time to erode deep southeast-oriented valleys headward from the newly eroded Powder River valley west wall. In other words, the southeast-oriented flood flow to the newly eroded Powder River valley was beheaded and reversed by headward erosion of the deep Tongue River valley almost as soon as the Powder River valley had been eroded. The Powder River valley eroded southeast and southwest from the deep northeast-oriented Yellowstone River valley (see figure 1). The Tongue River valley eroded southeast and southwest from the same northeast-oriented Yellowstone River valley (although from a point southwest of where the Powder River valley eroded south). Tongue River valley (and Tongue River tributary valley) headward erosion beheaded and reversed flood flow routes to the newly eroded Powder River valley almost as fast as the Powder River valley was eroded, which provides evidence of the magnitude of the southeast-oriented flood and the amount of erosion flood waters accomplished. Figure 8 evidence and all evidence presented here and in essays for nearby drainage divide areas indicates flood erosion of the southeast Montana and northeast Wyoming region occurred rapidly.

North end of Tongue River-Hanging Woman Creek drainage divide

Figure 9: North end of Tongue River-Hanging Woman Creek drainage divide. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the north end of the Tongue River-Hanging Woman Creek drainage divide area and is located west of the figure 6 map area and includes overlap areas with figures 5 and 6. The northeast-oriented Tongue River flows from the figure 9 southwest corner to the figure 9 north edge. Hanging Woman Creek flows north somewhat east of the figure 9 center. Note southeast-oriented Tongue River tributaries from the west and northwest-oriented Tongue River tributaries from the east. Also note east and southeast-oriented Hanging Woman Creek tributaries from the west and northwest-oriented Hanging Woman Creek tributaries from the east. Figure 9 evidence can be explained in the context of headward erosion of the north-oriented Hanging Woman Creek valley across southeast-oriented flood flow and subsequently headward erosion of the deep northeast-oriented Tongue River valley across the same southeast-oriented flood flow routes. The source of the flood waters cannot be determined from evidence here. However, the Missouri River drainage basin landform origins research project essays when taken as a group can be used to trace flood waters headward toward the flood water source. A logical flood water source is rapid melting of a thick North American ice sheet, which was located in a deep “hole” that had been eroded by ice sheet erosive action and formed by ice sheet weight and that was located approximately in the location where North American continental ice sheets are usually thought to have been located. Such a flood water source would also explain why deep northeast-oriented valleys were eroding headward to capture immense southeast-oriented floods and to divert flood waters further and further to the northeast into space in the deep “hole” the rapidly melting thick ice sheet had once occupied.

Tongue River-Hanging Woman Creek drainage divide northwest of Decker Mine

Figure 10: Tongue River-Hanging Woman Creek drainage divide northwest of Decker Mine. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 10 illustrates the Tongue River-Hanging Woman Creek drainage divide area south and slightly west of the figure 9 map area and west of the figure 7 map area and includes overlap areas with figure 7. Tongue River Reservoir is located in the figure 10 west center and the Tongue River flows northeast from it. North-northwest oriented Hanging Woman Creek is located in the figure 10 northeast corner. Tongue River tributaries from the east are west or west-northwest oriented, although some turn northwest to enter the Tongue River. Hanging Woman Creek tributaries from the west are east-southeast oriented, although some have northeast-oriented tributaries. Shallow high level through valleys link headwaters of the east-oriented Hanging Woman Creek tributaries with headwaters of the west-oriented Tongue River tributaries and provide evidence flood waters once flowed across the present day Tongue River-Hanging Woman Creek drainage divide. The through valleys provide further evidence flood waters originally flowed on a topographic surface at as high as the highest figure 10 elevations today. The deep Hanging Woman Creek valley and the deep Tongue River valley were eroded into that high level topographic surface as were all Hanging Woman Creek and Tongue River tributary valleys. Depth of the present day valleys below ridges forming the present day drainage divides provides a measure of the amount of erosion flood waters accomplished and of the magnitude of the flood involved.

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