Birch Creek-Teton River drainage divide area landform origins, Pondera and Teton Counties, Montana, USA

Authors

Abstract:

Topographic map interpretation methods are used to determine landform origins for the Birch Creek-Teton River drainage divide area located in Pondera and Teton Counties, Montana. Birch Creek originates along the east-west continental divide and flows onto the Montana plains where it is a northeast-oriented tributary to the Two Medicine River, which then flows to the Marias River. The Teton River also originates along the continental divide and flows in an east direction onto the Montana plains where it joins the Marias River near Loma, Montana to then join the Missouri River. In the mountains near the continental divide south-southeast oriented Teton River headwaters and tributary valleys are linked by deep north-south oriented through valleys with north-northwest oriented Birch Creek tributary valleys. These through valleys and many similar through valleys in the Birch Creek-Teton River drainage divide area provide evidence of south-southeast oriented flood flow channels which were eroded into a high level surface equivalent in elevation to the present day mountain tops. Flood waters were derived from a rapidly melting thick North American ice sheet, which was located in a deep “hole,” and were flowing along the deep “hole’s” west and southwest rim. Probably at that time the Rocky Mountains did not stand high above surrounding regions as they do today and were probably being uplifted as flood waters flowed across the region. Flood waters flowed along and across the present day continental divide with headward erosion of deep valleys from the west and the east capturing the flood flow and also beheading south-oriented flood flow channels to create the continental divide. Flood waters on north ends of beheaded flood flow channels reversed flow direction to erode north-oriented tributary valleys, such as the north-northwest oriented Birch Creek tributary valleys. Evidence for massive south- and east-oriented flood flow and deep flood erosion is found east of the mountains and includes through valleys and evidence of former anastomosing channel complexes. Headward erosion of east-oriented valleys occurred in sequence from south to north with headward erosion of northern valleys beheading flood flow to the newly eroded valley(s) immediately to the south.

Preface:

The following interpretation of detailed topographic map evidence is one of a series of essays describing similar evidence for all major drainage divides contained within the Missouri River drainage basin and for all major drainage divides with adjacent drainage basins. The research project is interpreting evidence in the context of a previously unexplored deep glacial erosion paradigm, which is fundamentally different from most commonly accepted North American glacial history interpretations. Project essays available at this site may be found by selecting desired Missouri River tributaries and/or states from this essay’s sidebar category list.

Introduction

  • The purpose of this essay is to use topographic map interpretation methods to explore the Birch Creek-Teton River drainage divide area landform origins in Pondera and Teton Counties, Montana, 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 providing a link to those essays in a comment here.
  • This essay is also exploring a new geomorphology paradigm in which erosional landforms are interpreted as evidence left by immense glacial melt water floods. Implied in that interpretation is the immense floods were derived from a thick North American ice sheet that created a deep “hole” in the North American continent and also melted fast. The previously unexplored paradigm being tested in this and other essays in the Missouri River drainage basin landform origins research project is a thick North American ice sheet, comparable in thickness to the Antarctic ice sheet, occupied the North American region usually recognized to have been glaciated, and through its weight and erosive actions created a deep North American “hole”. The southwestern rim of that deep “hole” is today preserved in the high Rocky Mountains. The ice sheet through its weight and deep erosion (and perhaps deposition along major south-oriented melt water flow routes) caused significant crustal warping and tectonic change, through its action of melting fast produced immense floods that flowed across the continent, and through its action of melting fast systematically opened up space in the ice sheet created “hole” so headward erosion of newly developed north-oriented drainage systems captured immense south-oriented melt water floods and diverted immense melt water floods north into space the ice sheet had once occupied.
  • If this previously unexplored paradigm is correct the geographic region explored by this essay should contain evidence of immense floods that were captured by headward erosion of new valley systems so as to cause the floods to flow in a different direction. Ability of this previously unexplored paradigm to explain Birch Creek-Teton River drainage divide area landform evidence in Pondera and Teton Counties, Montana will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm (see menu at top of page for a paradigm related essay). This essay is included in the Missouri River drainage basin landform origins research project essay collection.

Birch Creek-Teton River drainage divide area location map

Figure 1: Birch Creek-Teton 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 Birch Creek-Teton River drainage divide area location map and shows a region in north central Montana. The southeast corner of Glacier National Park is located in the figure 1 northwest corner region. Great Falls, Montana is the largest city shown and is located in the figure 1 southeast quadrant. The Missouri River flows in a northeast direction from the figure 1 south center edge to Great Falls, Fort Benton, Loma and the figure 1 east center edge. The Teton River is an east-oriented tributary joining the Missouri River near Loma and originates along the east-west continental divide, which is unlabeled in figure 1, but which extends in a south-southeast direction from Marias Pass (near figure 1 northwest corner) to the figure 1 south edge (west half). The Marias River also joins the Missouri River near Loma and is formed at the confluence of Cut Bank Creek and the Two Medicine River south and slightly east of Cut Bank (in figure 1 northwest quadrant) and flows in an east-southeast direction to and beyond Lake Elwell and then turns to flow in a south direction to join the Missouri River. Cut Bank Creek and the Two Medicine River also originate along the east-west continental divide in and near Glacier National Park and like the Teton River flow out onto the Montana plains to form the Marias River. Birch Creek is a northeast, east, and northeast-oriented Two Medicine River tributary also originating along the continental divide and flowing onto the Montana plains. The unnamed northeast-oriented Birch Creek tributary flowing through the town of Dupuyer is Dupuyer Creek and will be shown on the topographic maps below. West of the continental divide the northwest-oriented Middle Fork Flathead River and north-northwest oriented South Fork Flathead River flow to the south-oriented Flathead River west of the figure 1 map area. The Flathead River flows to northwest-oriented Clark Fork with water eventually reaching the Columbia River and the Pacific Ocean. The Birch Creek-Teton River drainage divide area investigated in this essay is located south of Birch Creek and north of the Teton River. The Two Medicine River-Birch Creek drainage divide area landform origins east of the mountains essay and the Two Medicine River-Birch Creek drainage divide area landform origins near the continental divide essay describe the region directly to the north. The Marias River-Pondera Coulee drainage divide area landform origins essay and the Marias River-Teton River drainage divide area landform origins essay describe the region to the east. Essays for Marias River drainage divide areas can be under the Marias River category (see sidebar category list).
  • Landforms in the Birch Creek-Teton River drainage divide area are interpreted in the context of the rapid melt down of a thick North American ice sheet, which was located in a deep “hole.” The deep “hole” evolved after the ice sheet was formed and was created by deep glacial erosion (under the ice sheet itself) and by crustal warping of regions elsewhere on the North American continent, especially in western North America. Today the upper Missouri River drainage basin, which is located in Montana and northern Wyoming, and the Saskatchewan River drainage basin in southwest Alberta represent the deeply eroded southwest wall of the deep “hole.” The western and southwest deep “hole” rim is today located along the crests of high Rocky Mountain ranges and in figure 1 follows the east-west continental divide. At one time the thick ice sheet stood high above the surrounding continent, which means it stood high above the present day Rocky Mountains. Ice-marginal melt water floods from further north in Canada flowed in south and southeast directions along what are now high Canadian and Montana Rocky Mountain crests into and across Wyoming and Colorado and even further south. At that time the deep “hole” was still evolving and the Rocky Mountains were being uplifted as the immense melt water floods flowed across them. Rocky Mountain uplift proceeded from the south to the north and systematically blocked the south and southeast oriented melt water floods, diverting the flood waters both to the east and to the west as deep southeast and southwest-oriented valleys eroded headward into the south and southeast flood flow route and created the present day east-west continental divide. In time Rocky Mountain uplift combined with ice sheet melting created a situation where the elevation of deep “hole” rim was higher than the elevation of the ice sheet surface (at least near the ice sheet southwest margin), which enabled deep east- and northeast-oriented valleys to erode headward from space being opened up in the deep “hole” up in the deep “hole” by ice sheet melting to capture the immense south and southeast oriented melt water floods. These deep east- and northeast-oriented valleys eroded headward from huge supra-glacial melt water rivers, which were carving gigantic south-oriented ice-walled canyons into the ice sheet surface. Of particular importance to the Montana and northern Wyoming Missouri River drainage basin history was a large ice-walled canyon crossing present day Saskatchewan, North Dakota, and South Dakota, which later became an ice-walled and bedrock-floored canyon and which detached the decaying ice sheet’s southwest margin. Today the Missouri Escarpment in Saskatchewan, North Dakota, and South Dakota is what remains of that giant ice-walled and bedrock-floored canyon’s southwest and west wall.
  • The east oriented Missouri River valley across northern Montana was the last of the east and northeast oriented valleys in the United States to erode headward from that giant southeast and south oriented ice-walled and bedrock-floored canyon and the east-oriented Missouri River tributary valleys seen in figure 1 eroded headward from that actively eroding Missouri River valley. While there are complexities beyond the scope of this essay, in general the east-oriented Missouri River tributary valleys eroded headward in sequence from south to north. In other words headward erosion of the east-oriented Sun River valley captured the south and southeast oriented melt water flood flow prior to headward erosion of the east-oriented Teton River valley, which beheaded flood flow routes to the newly eroded Sun River valley. Headward erosion of the Marias River valley and its tributary valleys next beheaded south and southeast oriented flood flow to the newly eroded Teton River valley. As can be seen in figure 1 there are several east and northeast oriented Marias River tributaries and the tributary valleys were also eroded headward in sequence from south and southeast to north and northwest. In figure 1 the Pondera Coulee valley captured the flood flow prior to headward erosion of the Marias River-Birch Creek-Dupuyer Creek valley. Headward erosion of the Birch Creek valley beheaded flood flow to the newly eroded Dupuyer Creek valley. Next Badger Creek valley headward erosion beheaded flood flow to the newly eroded Birch Creek valley. And Two Medicine River valley headward erosion beheaded flood flow to the newly eroded Badger Creek valley. Figure 1 only shows major drainage routes and there many complications, which only show up on detailed topographic maps. However, this generalized description should be kept in mind as the topographic maps are viewed. One of the complications is headward erosion of deep valleys often caused reversals of southeast- and south-oriented flood flow on north ends of beheaded flood flow channels. The northwest-oriented Middle Fork Flathead River and the north-northwest oriented South Fork Flathead River valley segments seen in figure 1 were eroded by such flood flow reversals. Previous to being beheaded by headward erosion of the deep south-oriented Flathead River valley the Middle Fork and South Fork Flathead River segments seen in figure 1 were southeast and south-southeast oriented flood flow channels with flood waters continuing into southwest Montana and probably further south.

Detailed location map for Birch Creek-Teton River drainage divide area

Figure 2: Detailed location map for Birch Creek-Teton River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 2 provides a detailed location map for the Birch Creek-Teton River drainage area in Pondera and Teton Counties, Montana. County boundaries are shown and Pondera and Teton Counties are labeled. Flathead County is west of the east-west continental divide, which is labeled in the figure 2 southwest quadrant. Green shaded areas are National Forest land while orange shaded areas are Blackfeet Indian Reservation lands. The unlabeled northwest-oriented stream flowing between Lodgepole Mountain and Gable Peaks is the Middle Fork Flathead River and its south-oriented tributary originating at Badger Pass is Strawberry Creek. East of the continental divide Birch Creek tributaries originate near Badger Pass and in the region of Gateway Pass (south of Badger Pass) and flow in northeast and north direction to join near Swift Reservoir and then to flow along the southeast boundary of the Blackfeet Indian Reservation to join the Two Medicine River just north of the figure 2 map area. The North and South Forks of Dupuyer Creek originate near Mt Patrick Gass and Mt Francis (slightly east and south of Gateway Pass) and flow in northeast directions to join and form northeast-oriented Dupuyer Creek, which flows through the town of Dupuyer and then joins Birch Creek just west of Lake Francis and the town of Valier. South and east of Dupuyer Creek is the northeast, east, and north-northeast oriented Dry Fork Marias River, which originates as several northeast-oriented forks south of the town of Dupuyer and which flows through the town of Ledger (north and east of Conrad). South of the Dry Fork Marias River headwaters is east-oriented Blacktail Creek which has several east-southeast oriented tributaries including Mauki Coulee and Farmers Coulee. South of Blacktail Creek is its east-oriented Muddy Creek tributary. Blacktail Creek is a Teton River tributary and originates just south of Mt Frazier and the South Fork Dupuyer Creek headwaters. South of Blacktail Creek and its Muddy Creek tributary is the east-oriented Teton River. Blacktail Creek joins the Teton River near Collins (near figure 2 southeast corner). Note how near Mt Patrick Gass a south-southeast oriented Teton River tributary is aligned with the north-northwest oriented South Fork Birch Creek. While no topography is shown this alignment suggests headward erosion of the northeast-oriented Birch Creek valley beheaded and reversed a south-southeast oriented flood flow channel to what was at that the actively eroding Teton River. Figure 9 will illustrate a topographic map of the region to better determine whether this hypothesis is supported by well-defined through valleys linking the two streams which today flow in opposite directions.

Dupuyer Creek-Dry Fork Marias River drainage divide area

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

 

 

  • Figure 3 illustrates the Dupuyer Creek-Dry Fork Marias River drainage divide area south and east of the town of Dupuyer, which is located in the figure 3 northwest quadrant. Dupuyer Creek flows in a northeast direction from the figure 3 west edge (just north of center) to the figure 3 north center and eventually joins northeast and east oriented Birch Creek, which is located north and west of the figure 3 map area. The North Fork of the Dry Fork Marias River originates a short distant south of Dupuyer and flows in an east-northeast direction to join the Dry Fork Marias River near the New Miami Colony in the figure 3 northeast quadrant. The Middle Fork Dry Fork Marias River flows in an east-northeast direction from the figure 3 west edge (south half) to join the northeast-oriented South Fork Dry Fork Marias River near the figure 3 center. A major Middle Fork tributary shown is northeast-oriented Jensen Coulee which drains from the figure 3 south edge (near the southwest corner). The South Fork flows in a northeast-direction from the figure 3 south center edge and northeast-oriented Bills Coulee is the major tributary shown. Note how the highway just southeast of the town of Dupuyer crosses the Dupuyer Creek-North Fork Dry Fork Marias River drainage divide by using a through valley which is defined by two 20-meter contour lines on each side (the map contour interval is 20 meters). Additional through valleys can be seen west of where the highway crosses the North Fork-Middle Fork drainage divide and to the south and southeast. More through valleys can be seen to the south along the Jensen Coulee-Bills Coulee drainage divide. Study of the figure 3 map area reveals many such subtle through valleys crossing present day drainage divides. The through valleys are water eroded features and provide evidence of drainage routes prior to headward erosion of deeper east and northeast-oriented valleys seen today. The number of the through valleys suggests there were multiple southeast and east oriented drainage routes such as might be found in an anastomosing channel complex. Each through valley has its own story to tell, but in general headward erosion of a deep east- or northeast-oriented valley beheaded east and/or southeast oriented flood flow routes to what was then the newly eroded east and/or northeast oriented valley immediately to the south and east. For example, east of Dupuyer there is a through valley linking the headwaters of an east-oriented Dry Fork Marias River tributary (north of the North Fork) with the northeast-oriented Dupuyer Creek valley. The through valley floor elevation is between 1220 and 1240 meters and a hill to the north rises to 1291 meters while the ridge south of Dupuyer rises to more than 1300 meters. This east-oriented through valley was eroded prior to headward erosion of the deeper northeast-oriented Dupuyer Creek valley, which captured the east-oriented flood flow and diverted the flood water in a northeast direction.

Detailed map of Dupuyer Creek-North Fork Dry Fork Marias River drainage divide area

Figure 4: Detailed map of Dupuyer Creek-North Fork Dry Fork Marias River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 4 provides a detailed topographic map of the Dupuyer Creek-North Fork Dry Fork Marias River drainage divide area south and east of the town of Dupuyer, which was seen in less detail in figure 3 above. Dupuyer Creek flows in a northeast direction in the figure 4 northwest quadrant. The North Fork Dry Fork Marias River originates in section 21 and flows in an east direction to the figure 4 east center edge. The Middle Fork Dry Fork Marias River flows in an east direction just south of the figure 4 map area with its south-facing north valley wall seen along the figure 4 south edge. The figure 4 map contour interval is 20 feet. Note in the northwest quadrant of section 21 a through valley linking the east oriented North Fork Dry Fork Marias River headwaters with a northwest and north oriented Dupuyer Creek tributary. The through valley floor at the drainage divide is between 4320 and 4340 feet and the hill to the north rises to more than 4420 feet while the hill to the south rises even higher. The through valley is a water eroded feature, which was eroded by east-oriented flood waters prior to headward erosion of the deeper northeast-oriented Dupuyer Creek valley. Another through valley is located in the southwest quadrant of section 14 and also links the Dupuyer Creek valley with the North Fork Dry Fork Marias River valley (highway 89 uses this through valley to cross the drainage divide southeast of the town of Dupuyer). The floor of this through valley has an elevation of between 4260 and 4280 feet at the drainage divide and the hill to the east rises to 4344 feet and the hill to the west rises even higher. This second through valley is also a water eroded feature and was eroded by southeast oriented flood waters moving to the North Fork Dry Fork Marias River prior to headward erosion of the deeper northeast-oriented Dupuyer Creek valley. Further south in the southwest corner of section 23 another northwest-southeast oriented through valley crosses the North Fork Dry Fork Marias River-Middle Fork Dry Fork Marias River drainage divide. The floor of this through valley at the drainage divide is between 4280 and 4300 feet and the hill to the east rises to 4359 feet while the hill to the west rises to 4429 feet. This through valley was eroded by southeast-oriented flood flow prior to headward erosion of the deeper east-oriented North Fork Dry Fork Marias River valley. Additional similar, but shallower through valleys can be seen. Each of the through valleys records a flood flow channel that existed prior to headward erosion of deep east- and northeast-oriented valleys immediately to the north and northwest. Flood waters probably initially flowed on a surface at least as high as the highest figure 4 elevations today and the figure 4 landscape was created as headward erosion of deeper northeast-oriented valleys captured the southeast- and east-oriented flood flow channels in sequence from south to north and from the southeast to the northwest.

Dupuyer Creek-Blacktail Creek drainage divide area

Figure 5: Dupuyer Creek-Blacktail Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 5 illustrates the Dupuyer Creek-Blacktail Creek drainage divide area south and west of the figure 3 map area and includes an overlap area with figure 3. Dupuyer Creek is formed in the figure 5 west center area at the confluence of its north-northeast oriented South and Middle Forks and its north-northeast and east oriented North Fork and then flows in a north-northeast and northeast direction to the figure 5 north edge (just west of center). Blacktail Creek flows in a northeast direction from the figure 5 south edge (west half) where it is joined by east-southeast oriented Cow Creek and then flows in an east-southeast direction to the figure 5 south center edge and then turns to flow as an east-oriented stream crossing above the figure 5 south edge before flowing south of the figure 5 southeast corner. Blacktail Creek is a Teton River tributary. Labeled southeast-oriented Blacktail Creek tributaries include Gansman Coulee, Toms Coulee, and Pings Coulee, with Hoy Coulee being a southeast-oriented Cow Creek tributary. The Middle Fork Dry Fork Marias River originates east of the confluence of the North, Middle, and South Forks Dupuyer Creek and flows in a northeast and east-northeast direction to the figure 5 northeast corner. Labeled Middle Fork Dry Fork Marias River tributaries include northeast oriented Bills Coulee and Jensen Coulee with its northeast- and east-oriented Woods Coulee and its east- and northeast-oriented Ben English Coulee tributary. Dupuyer Creek and the Dry Fork Marias River are Marias River tributaries so we are seeing the Marias River-Teton River drainage divide. Probably the most interesting through valley in the figure 5 map area is located in the southwest quadrant between the north-northeast oriented South Fork Dupuyer Creek and the east-southeast oriented Gansman, Toms, Pings, and Hoy Coulee headwaters. The figure 5 contour interval is 20 meters and at the South Fork Dupuyer Creek-Gansman Coulee drainage divide the through valley floor elevation is between 1500 and 1520 meters. Toms, Pings, and Hoy Coulees originate on a higher level surface of between 1560 and 1600 meters in elevation (the divide elevation with Hoy Coulee divide is lower than the divide elevations for Toms and Pings Coulees). The erosional remnant to northeast rises to more than 1640 meters while much higher elevations are found along the mountain front just to the southwest. Today the multiple east-southeast and southeast oriented coulees provide evidence of what was once an east-southeast oriented anastomosing channel complex eroded onto the floor of the present day through valley. At that time there was no northeast-oriented Dupuyer Creek valley and the flood waters eroding the anastomosing channels were probably flowing in a south-southeast direction along what was probably a rising mountain front and also in an east direction from what are today high mountain areas to the west of figure 5 to what was then the actively eroding east-oriented Blacktail Coulee valley. Headward erosion of the deep Dupuyer Creek valley captured the south-southeast oriented flood flow and flood waters on the north ends of the beheaded flood flow routes reversed flow direction to erode what are today north-northeast oriented South Fork, Middle Fork, and North Fork Dupuyer Creek valley segments.

Detailed map of South Fork Dupuyer Creek-Gansman Coulee drainage divide area

Figure 6: Detailed map of South Fork Dupuyer Creek-Gansman Coulee drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 6 provides a detailed topographic map of the South Fork Dupuyer Creek-Gansman Coulee drainage divide area seen in less detail in figure 5 above. The South Fork Dupuyer Creek flows in a north-northeast direction from the figure 6 southwest corner to join the north-northeast oriented Middle Fork Dupuyer Creek and east-oriented North Fork Dupuyer Creek near the figure 6 north edge (west half) and then to flow to the figure 6 north edge. The Middle Fork Dry Fork Marias River originates in section 20 and flows in a north-northeast direction to the figure 6 north edge (east of center). Dupuyer Creek and the Dry Fork Marias River eventually reach the Marias River. Gansman Coulee originates in section 30 and drains in an east direction to section 29 and then in a southeast direction to the figure 6 southeast corner. Toms Coulee drains across the section 32 northeast quadrant to the figure 6 edge in section 33. Pings Coulee drains to the figure 6 south center edge in section 32 and Hoy Coulee drains to the figure 6 edge at the line between sections 31 and 32. Gansman Coulee, Toms Coulee, Pings Coulee, and Hoy Coulee as seen in figure 5 all drain eventually to Blacktail Creek, which eventually joins the Teton River. Ben English Coulee originates in section 28 and drains in an east direction to the figure 6 east center edge and eventually to the Middle Fork Dry Fork Marias River. Note how the east-oriented Ben English Coulee valley is linked by a through valley in section 28 to a west- and south-oriented Gansman Coulee tributary valley. Also note how in section 30 the Gansman Coulee valley is linked by two separate through valleys with the north-northeast oriented South Fork Dupuyer Creek valley. These through valley document what were once diverging east and east-southeast oriented flood flow channels moving flood waters to what were then the actively eroding Blacktail Creek and the actively eroding Middle Fork Dry Fork Marias River valleys. A through valley in the southeast quadrant of section 19 links the Middle Fork Dry Fork Marias River valley with the Ben English Coulee, the Gansman Coulee, and the South Fork Dupyer Creek valleys and providing evidence of still additional diverging flood flow channel. These flood flow channels were eroded into a high level surface at least as high as the present day high points in section 21 (5810 feet). Today elevations vary in the figure 6 map area although at the confluence of the North, Middle, and South Forks Dupuyer Creek the elevation is between 4720 and 4740 feet (the map contour interval is 20 feet) suggesting as much as 1000 feet of erosion occurred as flood waters flowed across the region. How much material was stripped from the figure 6 map area before the surface represented by the high point in section 21 was reached cannot be easily determined, although it is possible flood waters stripped significant thicknesses of bedrock material from the entire figure 6 map area before that time.

Blacktail Creek-Teton River drainage divide area

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

 

 

  • Figure 7 illustrates the Blacktail Creek-Teton River drainage divide area south and somewhat west of the figure 5 map area and includes overlap areas with figure 5. The Teton River flows in a south-southeast direction from the figure 7 northwest corner to the figure 7 southwest quadrant. In the figure 7 southwest quadrant the Teton River makes a short northeast jog and then flows in a south, southeast, and south-southeast direction to near the figure 7 south edge. Once near the figure 7 south edge the Teton River flows in an east direction to the figure 7 south edge (near the figure 7 southeast corner). Labeled Teton River tributaries from the north and east include south oriented Jones Creek and southwest-oriented Massey Creek and the East Fork (Teton River). Note how Massey Creek originates as a north-oriented stream and then turns to become a south-oriented stream before turning to flow in a southwest direction. Also note south-oriented East Fork headwaters and a south-oriented East Fork tributary. Teton River tributaries from the west are oriented in northeast and east directions. Blacktail Creek originates in the figure 7 northwest quadrant as a north-oriented stream (west of Mount Werner) and then flows through Blackleaf Canyon (north of Mount Werner) and then to the figure 7 north center edge. North of figure 7 Blacktail Creek turns to flow in an east-southeast direction back into the figure 7 map area and to the figure 7 east edge (just south of the northeast corner). Muddy Creek is an east-oriented stream originating south of Mount Werner and then turning to flow in a southeast direction to the figure 7 east center edge. East of figure 7 Muddy Creek turns to flow in a northeast direction and to join Blacktail Creek, which eventually joins the Teton River. Labeled east-oriented Blacktail Creek tributaries include Rinker Creek, Blindhouse Creek, and Clark Fork. Note how streams east of the mountain front generally flow in east directions while in the mountain region many streams are flowing in north-south oriented valleys. These north-south oriented valleys are probably eroded along zones of geologic weakness, however they also reflect former south- and southeast-oriented flood flow routes. Apparently east-oriented flood waters removed most evidence for the south- and southeast-oriented flood flow routes east of the mountain front, although some shallow through valleys can be seen crossing drainage divides especially south of Clark Fork. However in the mountain area headward erosion of east-oriented valleys captured the south-oriented flood flow (see Jones Creek and south-southeast oriented Teton River headwaters) or beheaded and reversed the south-oriented flood flow to erode north-oriented valleys (see Blacktail Creek headwaters). Headward erosion of the deep Teton River valley eroded headward into what was then a rising mountain region and captured the south-oriented flood flow first. Headward erosion of the deep Jones Creek and south-southeast oriented Teton River headwaters valleys limited the ability of the deep east-oriented Clark Fork, and Blindhouse Creek valleys to erode far into the mountain region. Muddy Creek valley headward erosion next beheaded south-oriented flood flow to the what was then the actively eroding Jones Creek valley. Next headward erosion of the southwest-oriented East Fork Teton River valley beheaded south-oriented flood flow to the actively eroding Muddy Creek valley. Headward erosion of the deep Blacktail Creek valley next beheaded and reversed south-oriented flood flow to the actively eroding East Fork Teton River valley. These capture events suggest either the mountain region of figure 7 was not as high above the plains area to the east as it is today or that the plains area was then covered with bedrock material which was subsequently removed by deep flood water erosion. Probably a combination of the two hypotheses occurred.

Detailed map of Blacktail Creek-Muddy Creek drainage divide area

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

 

 

  • Figure 8 is a detailed topographic map of the Blacktail Creek-Muddy Creek drainage divide area seen in less detail in figure 7 above. Blacktail Creek originates in the section 22 northwest quadrant and flows in a north-northwest direction into section 15 where it turns to flow in an east direction through Blackleaf Canyon and then to the figure 8 east edge (north half). Muddy Creek originates as a north-northwest oriented stream in the northeast corner of section 28 and then turns to flow in more of an east direction to the figure 8 east edge (south half). The East Fork Teton River flows in a south direction into section 21 and then in a southwest and south-southwest direction to the figure 8 southwest corner. A south-oriented East Fork tributary flows from section 17 to join the East Fork in the section 20 southeast quadrant. The north-oriented stream flowing in the west half of section 9 (figure 8 northwest quadrant) is Rival Creek, which flows to the South Fork Dupuyer Creek. Note how the various present day drainage routes are linked by through valleys crossing all of the drainage divides. Some of the through valleys are deep such as the through valley linking the Blacktail Creek valley with the Muddy Creek valley found in the southwest corner of the region labeled PB 45. The contour  interval in the figure 8 northeast quadrant is 20 feet while it is 40 feet elsewhere on the map. The through valley floor elevation at the drainage divide is between 6100 and 6120 feet. The ridge to the east rises to 6753 feet while Mount Werner to the west rises to 8090 feet, which means the through valley is at least 630 feet deep and probably was deeper when eroded. The through valley was eroded by south-oriented flood flow to what was then the actively eroding Muddy Creek valley prior to headward erosion of the deep east-oriented Blacktail Creek valley. Another interesting deep through valley is found in the northeast corner of section 21 and links the north-oriented Blacktail Creek headwaters valley with the southwest-oriented East Fork Teton River valley and the north-oriented East Fork headwaters valley (which is linked by a through valley with the Muddy Creek headwaters valley).  This section 21 through valley has a floor elevation at the drainage divide of between 6960 and 7000 feet and Mount Werner to the east rises to 8090 feet while the spot elevation in the section 15 south center region reads 7873 feet. In other words this through valley linking the Blacktail Creek headwaters with the East Fork Teton River headwaters is more than 870 feet deep. These through valleys are just a few examples of through valleys seen on figure 8. Much shallower through valleys appear as saddles between mountain peaks such as the saddles in section 22 along the ridge extending west from Mount Werner. These saddles like the deeper through valleys are water eroded features and are evidence of former south-oriented flood flow routes, which were beheaded by headward erosion of the deeper valleys. The through valleys provide evidence of flood flow channels across this mountainous region which initially flowed on a surface at least as high as the present day mountain tops. Probably the mountains were being uplifted as flood waters flowed across them and eroded the deep valleys seen today.

Birch Creek-Teton River drainage divide area

Figure 9: Birch Creek-Teton River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 9 illustrates the Birch Creek-Teton River drainage divide area west and north of the figure 7 map area and includes an overlap area with figure 7. The east-west continental divide extends in an east and then south-southeast direction from the figure 9 northwest corner along the crest of the Lewis and Clark Range to the figure 9 south center edge. Strawberry Creek is the south-oriented stream originating near the figure 9 northwest corner at Badger Pass (unlabeled in figure 9) and near the figure 9 southwest corner turning to flow in a southwest and west direction to the figure 9 west edge (just north of southwest corner). West of figure 9 Strawberry Creek joins other streams to become the northwest-oriented Middle Fork Flathead River, which eventually flows to the south-oriented Flathead River with water eventually reaching the Pacific Ocean. North of Badger Pass (and not seen in figure 9) are northwest-oriented headwaters of South Badger Creek, with Badger Creek eventually flowing to the Two Medicine River which then flows to the Marias River. Badger Pass is deep north-south oriented through valley crossing the continental divide and provides evidence of a south-oriented flood flow channel which was captured by deep Middle Fork Flathead River valley headward erosion (to form the Strawberry Creek U-turn) and then beheaded and reversed by headward erosion of the Badger Creek valley to erode the northwest-oriented South Badger Creek valley segment. East of the continental divide the Middle Fork Birch Creek originates west of Mount Dewyer (in figure 9 north center area) and flows in a north and northeast direction to the figure 9 north center edge. The South Fork Birch Creek originates near Gateway Pass (on continental divide south of Mount Dewyer) and flows in north-northeast and north-northwest direction (east of Mount Dewyer) to join the Middle Fork Birch Creek near the figure 9 north center edge. Note the north-northwest oriented South Fork Birch Creek tributaries including Crazy Creek, Circus Creek, Lake Creek, and Phone Creek. South of the Phone Creek headwaters are headwaters of the south-southeast oriented North Fork Teton River, which flows to the figure 9 south edge (east half). The East Fork Teton River can be seen in the figure 9 southeast corner. Note how the south-southeast oriented North Fork Teton River headwaters valley is linked by a through valley with the north-northwest oriented Phone Creek valley. The through valley was eroded by south-southeast oriented flood flow which was subsequently beheaded and reversed by headward erosion of the deep northeast-oriented Birch Creek valley. Bruce Creek is a south-southeast and east oriented Teton River tributary originating south of the north-northwest oriented Crazy Creek headwaters. A through valley links the Bruce Creek headwaters valley with the Crazy Creek valley although the through valley floor is much higher than the opposing valley floors on either side. Study of the figure 9 map area reveals many other through valleys crossing the various drainage divides. Some through valleys are deep, but many of the through valleys look more like saddles on high ridges. Each of these through valleys provides evidence of former flood flow routes with the majority of the through valleys suggesting massive south-southeast oriented flood flow across the figure 9 map area.

Detailed map of Phone Creek-Teton River drainage divide area

Figure 10: Detailed map of Phone Creek-Teton River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

 

  • Figure 10 provides a detailed topographic map of the Phone Creek-Teton River drainage divide area seen in less detail in figure 9 above. Phone Creek originates in section 35 and flows in a north-northwest and north-northeast direction to the figure 10 north edge (west half). North of the figure 10 map area Phone Creek makes several jogs, but generally flows in a north-northwest direction to join the South Fork Birch Creek (see figure 9). South of the Phone Creek headwaters in sections 1 and 2 are Teton River (North Fork) headwaters with the Teton River flowing in a south-southeast direction to the figure 10 south edge (west half). Note the through valley in the southwest corner of the section labeled PB 44 linking the Phone Creek headwaters valley with the Teton River headwaters valley. The figure 10 map contour interval is 40 feet and the through valley floor elevation at the drainage divide is between 6840 and 6880 feet. Elevations on the ridge to the east rise to 8082 feet while Bloody Hill to the west has an elevation of 8074 feet. These elevations suggest the through valley is at least 1200 feet deep. The through valley is actually more complicated and two other higher level channels can also be seen to the west of the deepest channel. These through valleys were eroded by south-southeast oriented flood flow moving to what was then the actively eroding Teton River valley. At that time there was no Birch Creek valley to the north (nor other deep east-oriented valleys further north). Flood water were freely flowing on a surface equivalent to the 8000 mountain tops today in a south-southeast direction across the region and were being captured by headward erosion of the deep east-oriented Teton River valley. Probably at that time the region had not yet been uplifted to reach present day elevations and uplift was probably occurring as flood waters flowed across the region. Headward erosion of the deep northeast-oriented Birch Creek valley subsequently beheaded the south-southeast oriented flood flow routes to the actively eroding Teton River valley. Flood waters on north ends of the beheaded flood flow channels reversed flow direction to erode the north and north-northwest oriented Birch Creek tributary valleys (e.g. Phone Creek valley). The north-northwest oriented stream in the west half of section 31 which turns to flow in an east direction in section 30 is the North Fork Dupuyer Creek. Note how its tributaries from the south also originate as north-northwest oriented streams providing evidence their valleys were eroded by reversals of south-southeast oriented flood flow channels. The north- and east-oriented stream in the figure 10 southeast corner area is the South Fork Dupuyer Creek. Note how in the southeast corner of section 32 a deep thorough valley links the north-northwest oriented headwaters of Washout Creek (flowing to the North Fork Dupuyer Creek) with a south and southeast oriented South Fork Dupuyer Creek tributary valley. The through valley floor elevation at the drainage divide is between 6640 and 6680 feet while mountains on either side rise more than 1200 feet higher, if not more. Many other shallower through valleys can also be found in the figure 10 map area and each through valley provides evidence of a former flood flow channel. Flood water initially flowed on a surface equivalent to the tops of the highest figure 10 mountain peaks and the through valleys, including the deep through valleys, were eroded into that high level surface.

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.

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