Rosebud Creek- Rock Creek drainage divide area landform origins north of the Beartooth Mountains, Montana, USA

Authors


Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between Rosebud Creek and Rock Creek north the Beartooth Mountains, which are located along the Montana-Wyoming state line east of Yellowstone National Park. West and East Rosebud Creek originate in the high Beartooth Mountains and flow in northeast and north-northeast directions to form Rosebud Creek, which then joins the northeast-oriented Stillwater River. The Stillwater River then flows to the east and northeast oriented Yellowstone River. Rock Creek also originates in the high Beartooth Mountains east of the East Rosebud Creek headwaters and flows in an east, northeast, and north-northeast direction to join the northeast oriented Clarks Fork of the Yellowstone River near Silesia, Montana, which then flows in a northeast direction to join the northeast Yellowstone River near Laurel, Montana. The Clarks Fork of the Yellowstone River also originates in the high Beartooth Mountains near the north oriented Stillwater River headwaters with the Clarks Fork of the Yellowstone River first flowing in a southeast direction before turning to flow in a northeast and north-northeast direction. The Rosebud Creek-Rock Creek drainage divide area north of the Beartooth Mountains is a region of diverging and converging through valleys eroded across present day drainage divides, which are characteristic of flood formed anastomosing channel complexes. Floodwaters in some areas were flowing in south and southeast directions while in other areas appear to have been flowing in a north direction from the Beartooth Mountains to the east and northeast oriented Yellowstone River valley. Volumes of flood water were much greater than Beartooth Mountains valley glaciers could produce and floodwaters are interpreted to have been derived from a rapidly melting thick North American ice sheet located in a deep “hole” and generally were flowing in south and southeast directions from the ice sheet’s western margin in western Canada across Montana and into Wyoming until diverted in a north and northeast direction by Beartooth Mountains uplift and headward erosion of the deep northeast oriented Yellowstone River valley. At that time the Beartooth Mountains and other mountain ranges did not stand high above surrounding regions and floodwaters were at first free to move across the region, although crustal warping caused by the ice sheet’s great weight was raising the mountain ranges as floodwaters flowed across them. Beartooth Mountains uplift combined with headward erosion of the deep east and northeast oriented Rock Creek valley captured the south and southeast flood flow and diverted the floodwaters to the what at that time was a deep and actively eroding northeast oriented Yellowstone River valley, which had eroded headward from space in the deep “hole” being opened by the melting ice sheet. Next Beartooth Mountains uplift combined with Yellowstone River valley and Stillwater River-Rosebud Creek valley headward erosion captured the flood flow further to the west and diverted the floodwaters more directly to the newly eroded Yellowstone River valley. Beartooth Mountains uplift continued after flood flow across the region ended and at a later time valley glaciers further modified the Beartooth Mountains landscape.

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

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

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

Rosebud Creek-Rock Creek drainage divide area location map

Figure 1: Rosebud Creek-Rock 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 location map for the Rosebud Creek-Rock Creek drainage divide area north of the Beartooth Mountains. Yellowstone National Park is the yellow shaded area in the southwest corner of figure 1 (west half). The Montana-Wyoming state line extends in a west to east direction along the north edge of Yellowstone National Park. The Beartooth Mountains are not labeled in figure 1, but extend eastward from the northeast corner of Yellowstone National Park along the Montana-Wyoming border to the north-northeast oriented Clarks Fork of the Yellowstone River segment east of Red Lodge, Montana. The Yellowstone River flows from the Yellowstone National Park area in Wyoming in a northwest direction and once in Montana turns to flow in a northeast direction to Big Timber, Montana before turning to flow in an east-southeast direction to Columbus and then turning to flow in a northeast direction to Billings and the figure 1 northeast corner. The Stillwater River is unlabeled in figure 1 and originates north of Cooke City, Montana (near northeast corner of Yellowstone National Park) and flows in a northeast direction through Nye, Montana to join the Yellowstone River near Columbus. West Rosebud Creek originates near Granite Peak (north of Cooke City) and flow in a northeast direction to join north-northeast oriented East Rosebud Creek and to form north-northeast oriented Rosebud Creek, which joins the Stillwater River near Absarokee. The Clarks Fork of the Yellowstone River originates north of Cooke City, Montana and flows in a southeast direction into Wyoming before turning to flow in a northeast and north-northeast direction around the east end of the Beartooth Mountains to join the Yellowstone River near Laurel, Montana. Rock Creek is the unlabeled east and north-northeast oriented stream originating near Silver Run Peak and flowing to Red Lodge, Roberts, Boyd, and Joliet, Montana before joining the Clarks Fork of the Yellowstone River near Silesia. The Rosebud Creek-Rock Creek drainage divide area north the Beartooth Mountains illustrated and discussed here is generally located north and east of the highway extending from Roscoe to Red Lodge, Montana, south and east of Rosebud Creek-Stillwater River-Yellowstone River, and west of Rock Creek.

Looking at the big picture erosion history the figure 1 drainage routes developed as immense south and southeast oriented melt water floods flowed across the region and crustal warping raised the Beartooth Mountains at approximately the same time as the deep Yellowstone River valley eroded headward from a deep “hole” in which a large North American ice sheet was rapidly melting. The deep “hole” was located north and east of the figure 1 map area, which is located along the deep “hole’s” deeply eroded southwest wall. The east and northeast oriented Yellowstone River valley and its northeast oriented tributary valleys eroded headward from space in the deep “hole” being opened up by ice sheet melting to capture immense south and southeast oriented ice marginal floods flowing from western Canada across Montana. At that time mountain ranges in the figure 1 map area, including Beartooth Mountains, did not stand high above the surrounding regions and floodwaters could freely flow across the entire figure 1 map area. Ice sheet related crustal warping raised the Beartooth Mountains as the immense melt water floods flowed across the region. As the Beartooth Mountains were uplifted floodwaters flowing across the region began to carve deep valleys or flood flow channels into the rising mountain mass. At first these flood flow channels eroded headward from south oriented flood flow channels in the present day Bighorn Basin. The southeast oriented Clarks Fork of the Yellowstone River segment is located in one such deep valley, which was being carved headward into the rising mountain mass. Headward erosion of the deep northeast and north-northeast oriented Clarks Fork of the Yellowstone River valley segment later captured the deep southeast oriented flood flow channel and diverted the flood water to the newly eroded northeast oriented Yellowstone River valley (which was eroding headward from space in the deep “hole” the melting ice sheet had occupied). Headward erosion of the deep northeast oriented Rock Creek valley and its tributary valleys into a rising Beartooth Mountains mass next captured the south and southeast oriented flood flow. Headward erosion of the northeast oriented Rosebud Creek-Stillwater River valley (combined with continued Beartooth Mountains uplift) next beheaded and reversed south and southeast oriented flood flow routes in the Beartooth Mountains region and diverted the immense melt water floods in a northeast direction to the actively eroding and much deeper east and northeast oriented Yellowstone River valley (and to space in the deep “hole” being opened up by ice sheet melting).

Detailed location map for Rosebud Creek-Rock Creek drainage divide area

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

Figure 2 provides a more detailed location map for the Rosebud Creek-Rock Creek drainage divide area north of the Beartooth Mountains. The brown shaded area in the southwest corner of figure 2 represents areas in Yellowstone National Park. The west to east oriented dashed line near the south edge of figure 2 is the Montana-Wyoming state line with Montana being north of the line. Green shaded areas are National Forest lands, which are generally located in mountainous regions. The green shaded area north of Yellowstone National Park is located in the Absaroka Range while the green shaded areas east and northeast of Yellowstone National Park are located in the Beartooth Mountains. The Yellowstone River flows in a northeast direction from the west edge of figure 2 (north half) to Big Timber and then in an east-southeast direction to Columbus before turning to flow in a northeast direction to Laurel, Billings, and the northeast corner of figure 2. The Stillwater River originates north of the northeast corner of Yellowstone National Park and flows in a north and northeast direction through Nye and Beehive to join the Yellowstone River near Columbus. West Rosebud Creek originates east of the Stillwater River headwaters and flows in a northeast direction to join north-northeast oriented East Rosebud Creek and to form north-northeast oriented Rosebud Creek, which joins the Stillwater River near Absarokee. East Rosebud Creek flows through Alpine and Roscoe before joining West Rosebud Creek. Rock Creek originates in the Beartooth Mountains south and west of Red Lodge and flows in a north-northeast direction from Red Lodge to join the northeast oriented Clarks Fork Yellowstone River near Rockvale. Between East Rosebud Creek and Rock Creek several north-northeast streams originate along the Beartooth Mountains northeast margin and flow to Red Lodge Creek, which first flows in a north-northeast direction, but then turns to flow in a northeast direction to Cooney Reservoir and then in an east direction to join Rock Creek near Boyd. South of the headwaters of these north-northeast oriented Red Lodge Creek tributaries is the east oriented West Fork Rock Creek, which flows along the Beartooth Mountains northeast margin and which joins Rock Creek south of Red Lodge.

Yellowstone River-Rock Creek drainage divide area

Figure 3: Yellowstone River-Rock Creek drainage divide area north of Red Lodge, Montana. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of the Yellowstone River-Rock Creek drainage divide area north of the Beartooth Mountains. The Yellowstone River flows in an east, northeast, east-southeast, and northeast direction near the north edge of figure 3. Clarks Fork of the Yellowstone River flows in a north and northeast direction near the east edge of figure 3 and joins the Yellowstone River north and east of figure 3. Joliet is the small town located just north of the south center edge of figure 3. Rock Creek flows in a northeast direction from the south edge of figure 3 (near Joliet) to join the north oriented Clarks Fork of the Yellowstone River near the small of Rockvale. Farewell Creek flows in a northeast and east direction from the south end of Harris Hill to join Clarks Fork near the small town of Silesia. Bellion Creek is the north oriented Yellowstone River tributary west of Harris Hill. Cole Creek flows in a north-northeast direction from the southwest quadrant of figure 3 to join the Yellowstone River near the north center edge of figure 3. Rye Grass Creek is the north-northeast oriented Yellowstone River tributary west of Cole Creek. Note how Farewell Creek headwaters, Bellion Creek headwaters, and headwaters of northwest oriented Cole Creek tributaries are linked by through valleys with south oriented Rock Creek tributaries. The map contour interval for figure 3 is 50 meters and the through valleys are defined by one or more contour lines. Through valleys west of Harris Hill, especially those linking the northwest oriented Cole Creek tributary valleys with the Rock Creek valley were probably eroded by reversals of flood flow on what began as southeast oriented flood flow channels that were beheaded by headward erosion of the much deeper north-northeast oriented Cole Creek valley (from what was then an actively eroding Yellowstone River valley head). The through valleys east of Harris Hill were probably eroded by north oriented flood flow channels moving captured southeast oriented flood flow to the newly eroded and much deeper Yellowstone River valley. Floodwaters closer to the Clarks Fork of the Yellowstone River valley were coming from the south, although before being beheaded and reversed by headward erosion of the much deeper Yellowstone River valley the floodwaters had moved in a south direction on the Clarks Fork alignment as well. Headward erosion of the Farewell Creek valley captured the north oriented flood flow east of Harris Hill before headward erosion of the Rock Creek valley beheaded and reversed the flood flow to erode the south oriented Rock Creek tributary valleys.  The Rock Creek valley upstream from figure 3 was eroded headward by large volumes of north oriented flood flow, which was coming from the Beartooth Mountains, which are located south of figure 3.

Detailed map of Farewell Creek-Rock Creek drainage divide area

Figure 4: Detailed map of Farewell Creek-Rock Creek 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 Farewell Creek-Rock Creek drainage divide area seen in less detail in figure 3. Harris Hill straddles the boundary between sections 29 and 30 near the north edge of figure 4. Farewell Creek originates near the south end of Harris Hill and flows in a northeast direction to the northeast corner of figure 4. Rock Creek can be seen flowing in a northeast direction across the southeast corner of figure 4. A through valley near the northwest corner of section 32 links the Farewell Creek headwaters with a south-southeast oriented Rock Creek tributary. The map contour interval for figure 4 is 20 feet and the through valley floor elevation at the drainage divide is between 3840 and 3860 feet. The hill to the east rises to at least 3924 feet and the hill to west rises to 4092 feet suggesting the through valley is at least 64 feet deep if not deeper. An even more interesting through valley is located near the corner of sections 1, 2, 35, and 36 (in southwest quadrant of figure 4) and links a northwest oriented Cole Creek tributary valley with a south oriented Rock Creek tributary valley. The floor elevation of this second through valley at the drainage divide is between 4220 and 4240 feet. The hill to the north rises to 4354 feet while the hill to the south rises to 4364 feet suggesting the through valley is at least 114 feet deep. A third interesting through valley in section 36 links the north-oriented Bellion Creek headwaters valley with the south oriented Rock Creek tributary valley. The floor of this third through valley at the drainage divide is between 4160 and 4180 feet. Elevations rise to 4263 in section 31 to the east and to 4266 feet to the west in section 36 suggesting the through valley is between 80 and 100 feet deep. Flood flow across the region was first in a south and southeast direction and then as headward erosion of the deep Yellowstone River valley to the north beheaded the south oriented flood flow channels in sequence from east to west floodwaters on the north ends of beheaded flood flow routes reversed flow direction to create north oriented flood flow channels. These north oriented flood flow channels captured south and southeast oriented flood flow from yet to be beheaded and reversed flood flow channels further to the west. One such capture occurred in sections 25 and 26 where the newly reversed north oriented Bellion Creek flood flow channel captured southeast oriented flood flow moving on a present day northwest oriented Cole Creek tributary alignment. Headward erosion of the deeper north-northeast oriented Cole Creek valley (west of figure 4) beheaded and reversed the southeast oriented flood flow to erode the northwest oriented Cole Creek tributary valley.

Stillwater River-Red Lodge Creek drainage divide area south of Horseshoe Mountain

Figure 5: Stillwater River-Red Lodge Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Stillwater River-Red Lodge Creek drainage divide area west of figure 3 and includes an overlap area with figure 3. The Yellowstone River flows in an east direction to the northeast corner of figure 5. The Stillwater River flows in a northeast direction across the northwest corner of figure 5. Rock Creek flows in a northeast direction across the southeast corner of figure 5. Red Lodge Creek is an east oriented Rock Creek tributary flowing from Cooney Reservoir near the south edge of figure 5. Shane Ridge is the north-northwest to south-southeast oriented ridge forming the Stillwater River-Yellowstone River drainage divide in the north half of figure 5. Shane Creek is a north-northwest oriented Stillwater River tributary located along the southwest flank of Shane Ridge. Joe Hill Creek is the north-northwest oriented Stillwater River tributary west of Shane Creek and Whitebird Creek is the north oriented stream west of Joe Hill Creek. The map contour interval for figure 5 is 50 meters. Elevations near the southeast end of Shane Ridge rise to more than 1500 meters. While not seen in figure 5 elevations also rise to more than 1500 near the southwest corner of figure 5. Between the 1500-meter elevations the Stillwater River-Red Lodge Creek drainage divide has elevations in the 1400 to 1450 meter range. These lower elevations define a broad northwest to southeast oriented through valley linking the northeast oriented Stillwater River valley with the east oriented Red Lodge Creek valley. This broad northwest to southeast oriented through valley was eroded by southeast oriented flood flow moving to what was at that time the actively eroding east oriented Red Lodge Creek valley. At that time the deep northeast oriented Stillwater River valley had yet to be eroded and the actively eroding Yellowstone River valley head was probably still north of figure 5. Headward erosion of the deep Yellowstone River valley and its northeast oriented Stillwater River tributary valley beheaded the southeast oriented flood flow. Flood waters on the northwest and north ends of the beheaded flood flow routes reversed flow direction to erode the northwest oriented Shane Creek and Joe Hill Creek valleys and the north oriented Whitebird Creek valley.

Detailed map of Joe Hill Creek-Red Lodge Creek drainage divide area

Figure 6: Detailed map of Joe Hill Creek-Red Lodge Creek 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 Joe Hill Creek-Red Lodge Creek drainage divide area seen in less detail in figure 5.  Red Lodge Creek can be seen flowing in an east direction near the south edge of figure 6 (east half). Joe Hill Creek flows in a north-northwest direction from section 22 to the northwest corner of figure 6. The West Fork Shane Creek flows in a north direction from the north half of section 23 across section 14 to the north edge of figure 6 (near center). The East Fork Shane Creek can be seen flowing in a northwest direction in section 18 (near northeast corner of figure 6). Note how multiple northwest to southeast oriented shallow valleys cross the Stillwater River-Red Lodge Creek drainage divide, which extends from section 21 along the west edge of figure 6 to the northeast corner of figure 6. Those shallow valleys are evidence of former southeast oriented flood flow that once was moving to the actively eroding east oriented Red Lodge Creek valley. Headward erosion of the deep northeast oriented Stillwater River valley north and west of figure 6 beheaded the southeast oriented flood flow routes in sequence from east to west. Floodwaters on northwest and north ends of beheaded flood flow routes reversed flow direction to erode the northwest oriented East Fork Shane Creek valley, the north oriented West Shane Creek valley and the north-northwest oriented Joe Hill Creek valley and also to form the present day Stillwater River-Red Lodge Creek drainage divide.

Butcher Creek-Red Lodge Creek drainage divide area

Figure 7: Butcher Creek-Red Lodge Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the Butcher Creek-Red Lodge Creek drainage divide area south and west of figure 5 and includes a small overlap area with figure 5. Cooney Reservoir is located near the northeast corner of figure 7. Red Lodge Creek flows in a north and northeast direction from the south edge of figure 7 (east half) to Cooney Reservoir and joins northeast oriented Rock Creek east of figure 7. East oriented West Red Lodge Creek joins north oriented East Red Lodge Creek near the south edge of figure 7. Willow Creek is a north-northeast Red Lodge Creek tributary flowing to Cooney Reservoir east of Red Lodge Creek. Butte Creek is a north-northeast oriented Red Lodge Creek tributary flowing between Red Lodge Creek and Willow Creek. West of Red Lodge Creek north-northeast oriented Volney Creek joins its northeast and east oriented West Fork before joining Red Lodge Creek. Note multiple northeast oriented Volney Creek tributaries and their relationship to Spring Creek Bench. West of Spring Creek Bench is north oriented Butcher Creek, which joins north oriented East Rosebud Creek just north of figure 7. Coleman Bench serves as the narrow drainage divide between Butcher Creek and north oriented East Rosebud Creek. North-northeast oriented West Rosebud Creek is west of East Rosebud Creek and flows to the north edge of figure 7 near the town of Fishtail. The multiple north and north-northeast oriented valleys (and through valleys across present day drainage divides) suggest the region was once crossed by a north oriented anastomosing channel complex. Headward erosion of the deep east and northeast oriented Red Lodge Creek valley captured the north oriented flood flow east of the north oriented Butcher Creek valley while west of the Butcher Creek valley the flood flow was captured by headward erosion of the deep north oriented Rosebud Creek valley. South of Spring Creek Bench a northeast oriented through valley links the north oriented Butcher Creek valley with the Volney Creek valley and provides evidence of diverging and converging flood flow channels. What is important to remember is headward erosion of the northeast and east oriented Red Lodge Creek was capturing immense southeast oriented flood flow from the northwest and immense north oriented floods from the Beartooth Mountains to the south.

Detailed map of Butcher Creek –Red Lodge Creek drainage divide area

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

Figure 8 provides a detailed topographic map of the Butcher Creek-Red Lodge Creek drainage divide seen in less detail in figure 7 above. East Rosebud Creek flows in a north-northeast direction across the northwest corner of figure 8 and is located west of Coleman Bench. Butcher Creek flows in a north-northeast direction from the south edge of figure 8 (west of center) through sections 14 and 12 to section 1 where it turns to flow in a north-northwest and north direction to the north center edge of figure 8. West Red Lodge Creek flows in a northeast direction across the southeast corner of figure 8. Volney Creek is the northeast oriented stream located north and west of West Red Lodge Creek. Spring Creek Bench is the high area just north of where sections 1 and 6 meet the Standard Parallel. The east-northeast stream flowing along the base of the Spring Creek Bench southeast-facing wall is a Volney Creek tributary. Note how midway on the line separating sections 1 and 6 a through valley links the Butcher Creek valley with the east-northeast oriented Volney Creek tributary valley. The map contour interval for figure 8 is 20 feet and the through valley floor elevation at the drainage divide is between 5020 and 5040 feet. The high point on Spring Creek Bench is marked as 5389 feet and the high point in the northwest corner of section 18 is between 5460 and 5480 feet. In other words the through valley is at least 350 feet deep. An east-northeast diverging flood flow channel from the north oriented Butcher Creek flood flow eroded the through valley. Evidence of other converging and diverging north oriented flood flow channels can be seen throughout figure 8, with especially good evidence visible in sections 1 and 11. Immense north oriented floods eroded the figure 8 region and were coming from the area south of figure 8, which is today the high Beartooth Mountains. Floodwaters were flowing to what was at that time an actively eroding Yellowstone River valley and its various actively eroding tributary valleys. Volumes of north oriented flood water involved were much greater than can be accounted for by melting of valley glaciers in the high Beartooth Mountains to south and can best be explained by immense south and southeast oriented melt water floods from a rapidly melting thick North American ice sheet, with the south and southeast oriented floodwaters being diverted in a north direction by a rising Beartooth Mountains barrier toward what was at that time an actively eroding a very deep east and northeast oriented Yellowstone River valley.

East Rosebud Creek-West Fork Rock Creek drainage divide area

Figure 9: East Rosebud Creek-West Fork Rock Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the East Rosebud Creek-West Fork Rock Creek drainage divide area south and west of figure 7. West Rosebud Creek flows in a northeast direction across the northwest corner of figure 9. East Rosebud Creek flows from the southwest corner of figure 9 to the north edge of figure 9 (just west of center). Hellroaring Creek is the East Rosebud Creek tributary originating near Sylvan Peak and flowing in a northeast and north direction between East Rosebud Plateau and Red Lodge Creek Plateau. West Fork Rock Creek flows in a northeast and east-southeast direction from the south center edge of figure 9 to the east edge of figure 9 (just north of southeast corner). Most of the area shown in figure 9 is located in the Beartooth Mountains and the Beartooth Mountains northeast flank is evident in the north half of figure 9. The West and East Forks of Butcher Creek originate along the Beartooth Mountains northeast flank in the region east of East Rosebud Creek. Further east the West Fork Red Lodge Creek originates between the Red Lodge Creek Plateau and Bare Mountain and flows in a north-northeast and northeast direction to the north edge of figure 9 (near northeast corner). Based on present day topography large floods from further south and west in the Beartooth Mountains would be channeled into one of the deep canyons and would not flow to either the Butcher Creek or West Fork Red Lodge Creek headwaters areas. Yet as seen in figures 7 and 8 the Butcher Creek and Red Lodge Creek valleys show evidence of having been eroded by immense north oriented floods. The only explanation that seems possible is the north oriented floods occurred prior to headward erosion of the deep northeast and east-southeast West Fork Rock Creek valley. The deep through valley linking the West Fork Rock Creek valley with the north oriented West Fork Red Lodge Creek valley appears to provide evidence of the former flood flow channel that supplied floodwaters to the West Fork Red Lodge Creek drainage basin and to the Butcher Creek drainage basin, although the valley orientation suggests floodwaters were flowing to the east oriented West Fork Rock Creek valley. Such an interpretation requires north oriented floodwaters to have flowed across the Red Lodge Creek Plateau (and possibly the East Rosebud Plateau) and implies Beartooth Mountains uplift (or emergence) probably occurred as floodwaters were flowing across the region, including areas that today are high mountain ridges and drainage divides to the south. See the Rosebud Creek-Clarks Fork of the Yellowstone River, the Rock Creek-Clarks Fork of the Yellowstone River, and the Stillwater River-Lamar River essays for discussions of the high Beartooth Mountains regions to the south of the region illustrated and described in this essay.

Detailed map of West Red Lodge Creek-West Fork Rock Creek drainage divide area

Figure 10: Detailed map of West Red Lodge Creek-West Fork Rock Creek 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 West Red Lodge Creek-West Fork Rock Creek drainage divide area between the Red Lodge Creek Plateau and Bare Mountain seen in less detail in figure 9 above. The West Fork Rock Creek flows in an east-northeast direction from section 5 (near southwest corner of figure 10) to section 36 and the east edge of figure 10. Senia Creek is a southeast and south oriented tributary joining the West Fork Rock Creek near Camp Senia in section 35. Cascade Creek is a south-southeast oriented tributary originating in section 25 and joining the West Fork Rock Creek east of figure 10. The West Fork Red Lodge Creek originates in section 32 (north of the southwest corner of figure 10) and flows in a northeast direction across section 28 before turning to flow in a north direction to the north edge of figure 10. Note in the southeast quadrant of section 27 a through valley linking a north-northwest oriented West Fork Red Lodge Creek tributary valley with the south oriented Senia Creek valley. The map contour interval for figure 10 is 40 feet and the through valley floor elevation at the drainage divide is between 9120 and 9160 feet. Bare Mountain reaches an elevation of 9918 feet while much higher elevations are found on the ridge to the west suggesting the through valley is at least 750 feet deep. The through valley was eroded by floodwaters, but the flood flow appears to have been moving in an east direction and not a north direction. Apparently north oriented floodwaters from further west were being captured and diverted to flow to the actively eroding and deep West Fork Rock Creek valley head. A much higher and less obvious through valley south of the West Fork Red Lodge Creek headwaters in section 32 appears to have been eroded by north oriented flood flow, some of which was probably captured by headward erosion of the actively eroding east oriented West Fork Rock Creek valley. Other subtle through valleys seen in figure 10 suggest a complex pattern of flood flow movements as deep valleys eroded headward into the region. If the flood erosion origin interpretation of the present day deep valleys is correct volumes of flood water involved were immense and can only be explained by massive melt water floods from a rapidly melting thick North American ice sheet and cannot be accounted for by melting of Beartooth Mountains valley glaciers. However, upstream on the West Fork Rock Creek, East Fork Rosebud Creek, and West Fork Rosebud Creek there is evidence valley glaciers did exist and did modify what were pre-existing flood eroded valleys.

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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