Rosebud Creek- Clarks Fork of the Yellowstone River drainage divide area landform origins in the Beartooth Mountains east of Yellowstone National Park, Montana and Wyoming, USA

Authors


Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between north oriented Rosebud Creek headwaters and tributaries and south oriented Clarks Fork Yellowstone River tributaries in 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 a northeast direction to join the northeast oriented Stillwater River, which then joins the east and northeast oriented Yellowstone River near Columbus, Montana. Clarks Fork of the Yellowstone River and its south oriented tributaries originate in the high Beartooth Mountains just south of the Rosebud Creek headwaters with Clarks Fork flowing in a southeast direction before turning to flow in a northeast and north-northeast direction to join the Yellowstone River near Laurel, Montana, which is downstream from Columbus. Multiple through valleys eroded across high Beartooth Mountain ridges link the north oriented Rosebud Creek drainage basin with the southeast oriented Clarks Fork of the Yellowstone River valley segment and are interpreted to have been eroded as multiple south oriented flood flow channels prior to emergence of the Beartooth Mountains as a high mountain range. Floodwaters are interpreted to have been derived from a rapidly melting thick North American ice sheet located in a deep “hole” and were flowing in south and southeast directions from the ice sheet’s western margin in western Canada across Montana and into Wyoming. At that time the Beartooth Mountains and other mountain ranges did not stand high above surrounding regions and floodwaters were 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. Headward erosion of the deep northeast oriented Yellowstone River valley and its Rosebud Creek tributary valley across the massive southeast and south oriented flood flow captured the floodwaters and diverted the flood flow into space in the deep “hole” being opened up as the ice sheet melted and combined with Beartooth Mountains uplift created the Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide.

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-Clarks Fork of the Yellowstone River drainage divide area landform origins in the Beartooth Mountains east of Yellowstone National Park, Montana and Wyoming, 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 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-Clarks Fork of the Yellowstone River drainage divide area landform evidence in the Beartooth Mountains east of Yellowstone National Park will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area location map

Figure 1: Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area location map (select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

Figure 1 provides a location map for the Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide in the Beartooth Mountains east of Yellowstone National Park and illustrates a region of south-central Montana in the north half and northwest Wyoming in the figure 1 south half. Yellowstone National Park is the yellow shaded area in the southeast corner of figure 1 (west half). 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 near Red Lodge, Montana. The Yellowstone River flows from the Yellowstone National Park area in northwest Wyoming in a northwest direction and once in Montana turns to flow in a northeast direction to the north edge of figure 1 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 north edge (near northeast corner). The Stillwater River is unlabeled on figure 1, but is the north-northeast and northeast oriented tributary originating north of Silver Gate (at Yellowstone National Park northeast corner) and flowing through Nye before joining the Yellowstone River near Columbus. Rosebud Creek is the unlabeled northeast oriented tributary joining the Stillwater River near Absarokee, Montana. The Clarks Fork of the Yellowstone River originates south of the Rosebud Creek headwaters and north of Cooke City, Montana and flows in a southeast direction into Wyoming before turning to flow in a northeast and north-northeast direction to join the Yellowstone River near Laurel, Montana. The Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area illustrated and discussed here is located between the north oriented Rosebud Creek headwaters and the southeast oriented Clarks Fork of the Yellowstone River in the region east of Cooke City, Montana.

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 was 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 the deep “hole” 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. 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. 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 eventually captured the southeast oriented flood flow channel and diverted the flood water to the newly eroded northeast oriented Yellowstone River valley. Headward erosion of the deep northeast oriented Rosebud Creek valley and its tributary valleys from the actively eroding Yellowstone-Stillwater River valley next captured the south and southeast oriented flood flow, which had been moving to the actively eroding southeast oriented Clarks Fork of the Yellowstone River valley. Still later headward erosion of the deep northeast oriented Stillwater River valley (upstream from the Rosebud Creek valley) beheaded and reversed the final south and southeast oriented flood flow routes to the Clarks Fork of the Yellowstone River valley.  Ice sheet related crustal warping raised the Beartooth Mountains as the immense melt water floods flowed across the region and contributed to deep erosion of the Beartooth Mountains upland area and to formation of the present day Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide.

Detailed location map for Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area

Figure 2: Detailed location map Rosebud Creek-Clarks Fork of the Yellowstone River 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-Clarks Fork of the Yellowstone River drainage divide area in the Beartooth Mountains east of Yellowstone National Park. The brown shaded area in the southwest quadrant of figure 2 represents areas in Yellowstone National Park. The west to east oriented dashed line running through the northern margin of the Yellowstone National Park area is the Montana-Wyoming state 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 northwest direction in Yellowstone National Park and west of the figure 2 turns to flow in a north-northeast direction to flow across the northwest corner of figure 2. North of figure 2 the Yellowstone River turns again to flow in an east-southeast direction and can be seen flowing from Columbus to Laurel, Montana in the northeast quadrant of figure 2. The Stillwater River originates north of the northeast corner of Yellowstone National Park and flows in a north and northeast direction to join the Yellowstone River near Columbus. Rosebud Creek is the northeast oriented tributary joining the Stillwater River near Absarokee and is formed at the confluence of West Rosebud Creek and East Rosebud Creek. The Clarks Fork of the Yellowstone River originates south of Granite Peak (near the West Rosebud Creek headwaters) and flows in a south and southeast direction to near the south edge of figure 2 before turning to flow in a northeast and north-northeast direction to join the Yellowstone River near Laurel, Montana (near northeast corner of figure 2). Note south oriented tributaries flowing to the southeast oriented Clarks Fork of the Yellowstone River segment. These south oriented Clarks Fork tributaries originate on the Beartooth Plateau just south of the headwaters of northeast oriented East Rosebud Creek. As seen in the topographic maps illustrated below the Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area is today a high mountainous region.

Stillwater River-Clarks Fork of the Yellowstone River drainage divide area

Figure 3: Stillwater River-Clarks Fork of the Yellowstone River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of the Stillwater River-Clarks Fork of the Yellowstone River drainage divide area and is located along the Montana-Wyoming border directly northeast of the Yellowstone National Park northeast corner. Silver Gate in the southwest corner of figure 3 is the northeast entrance for Yellowstone National Park. The Stillwater River originates north of Silver Gate and flows in a north direction to the northwest corner of figure 3 and eventually reaches the east and northeast Yellowstone River near Columbus, Montana. Goose Creek is a southwest and west oriented tributary flowing from Goose Lake to the Stillwater River in the northwest quadrant of figure 3. The west-southwest oriented stream flowing from Cooke City through Silver Gate to the west edge of figure 3 is Soda Butte Creek and water in it eventually reaches the northwest oriented Yellowstone River in Yellowstone National Park. Note southeast oriented Sheep Creek and Miller Creek, which flow to Soda Butte Creek as barbed tributaries and which are linked by through valleys (or mountain passes) with the north oriented Stillwater River valley. East of Cooke City is Colter Pass and east of Colter Pass is the south-southeast oriented Clarks Fork of the Yellowstone River. Major tributaries flowing to the Clarks Fork include southeast oriented Fisher Creek, south oriented Lady of the Lake Creek, and the south-southeast and south-southwest oriented Broadwater River, all of which are linked by through valleys (or mountain passes) with the north oriented Stillwater River valley or the west oriented Goose Creek valley. The through valleys (or mountain passes) and the barbed tributaries to Soda Butte Creek all provide evidence of multiple southeast oriented flood flow channels such as might be found in an anastomosing flood flow channel complex. At the time floodwaters flowed across the figure 3 map area the Beartooth Mountains did not stand high above surrounding regions as they do today and floodwaters were free to flow across the region. Beartooth Mountains uplift occurred as floodwaters were flowing across the region. At first floodwaters carved deep flood flow channels into the rising mountain mass, but in time the rising mountain mass forced flood flow reversals that created the Stillwater River-Clarks Fork of the Yellowstone River drainage divide. Note Fossil Lake in the northeast quadrant of figure 3. The northeast oriented stream draining from Fossil Lake to the northeast corner of figure 3 is East Rosebud Creek. Figures 7 and 8 below illustrate and discuss through valleys (or mountain passes) linking Fossil Lake with south oriented Clarks Fork of the Yellowstone River tributaries.

Detailed map of Soda Butte Creek-Clarks Fork of the Yellowstone River drainage divide area

Figure 4: Detailed topographic map of the Soda Butte Creek-Clarks Fork of the Yellowstone 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 Soda Butte Creek-Clarks Fork of the Yellowstone River drainage divide area seen in less detail in figure 3 above. Cooke City is located in section 25 in the west half of figure 4. Soda Butte Creek originates in section 30 and flows in a west-southwest direction to the figure 4 west edge. Miller Creek flows in a southeast direction from the northwest corner of figure 4 to join west-southwest oriented Soda Butte Creek as a barbed tributary near the east edge of Cooke City. Colter Pass is located near the line between sections 20 and 29 just east of the Soda Butte Creek headwaters. Flowing in a south-southeast direction across the corner of sections 20, 21, 28, and 29 (just east of Colter Pass) is the Clarks Fork of the Yellowstone River, which is joined by south-southwest oriented Forage Creek and the southwest oriented Broadwater River in section 28. The mountain south of Colter Pass is Rams Pasture and it rises to more than 10,600 feet (the map contour interval for figure 4 is 40 feet). While not seen in figure 4 mountains north of figure 4 also rise to more than 10,600 feet. Colter Pass has an elevation of between 8040 and 8080 feet, suggesting it could be as much as 2500 feet deep. Colter Pass was eroded by southeast and east oriented flood flow moving to what was at that time an actively eroding southeast oriented Clarks Fork of the Yellowstone River valley. At least some of the floodwaters were moving across the Stillwater River-Clarks Fork of the Yellowstone River drainage divide while some of the flood water may have been moving in a northeast and east-northeast direction from the Yellowstone National Park area on the present day west-southwest and southwest oriented Soda Butte Creek alignment. Beartooth Mountains uplift combined with headward erosion of the deep northeast oriented Yellowstone River-Stillwater River valley north of figure 4 (from space in the deep “hole” the melting ice sheet had once occupied) caused a massive reversals of flood flow that eroded the north oriented Stillwater River headwaters valley. Continued headward erosion of the deep east and northeast oriented Yellowstone River valley subsequently beheaded and reversed south and southeast oriented flood flow routes across the eastern Yellowstone National Park area, which in return caused a reversal of the northeast and east-northeast oriented flood flow in the Colter Pass flood flow channel, which created the west-southwest oriented Soda Butte Creek drainage route seen today. Continued Beartooth Mountains uplift probably further raised the figure 4 region to produce present day elevations.

West Rosebud Creek-Broadwater River drainage divide area south of Horseshoe Mountain

Figure 5: West Rosebud Creek-Broadwater River drainage divide area south of Horseshoe Mountain. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the West Rosebud Creek-Broadwater River drainage divide area north of figure 3 and includes significant overlap areas with figure 3. The Stillwater River flows in a north direction near the west edge of figure 5. The Broadwater River is formed at the confluence of southeast oriented Star Creek and south oriented Zimmer Creek (in south center area of figure 3) and flows in a southeast direction to Broadwater Lake (seen along south edge of figure 5-east of center). South of Star Creek is Lady of the Lake and Lady of the Lake Creek flows in a south direction from the lake to the south center edge of figure 5. South of figure 5 Lady of the Lake Creek and the Broadwater River flow to the Clarks Fork of the Yellowstone River.  Zimmer Creek originates at Zimmer Lake and on the north side of the ridge north of Zimmer Lake is Grasshopper Glacier. West Rosebud Creek originates at the foot of Grasshopper Glacier and flows in a north direction to the north center edge of figure 5. West of Mount Zimmer (west of Zimmer Lake) is Goose Lake, which drains to southwest and west oriented Goose Creek and the north oriented Stillwater River. Note how today there are mountain passes (or through valleys linking the north oriented West Rosebud Creek valley with the south oriented Zimmer Creek valley and with the south oriented Goose Creek headwaters valley. The mountain pass linking the West Rosebud Creek and Zimmer Creek valleys is located between Mount Wilse and Iceberg Peak. The map contour interval for figure 5 is 50 meters and the pass elevation is between 3250 and 3300 meters. Mount Wilse rises to 3606 meters while Iceberg Peak rises to more than 3500 meters, which suggests the pass is at least 250 meters deep. The pass linking the north oriented West Rosebud Creek valley with the south oriented Goose Creek valley has about the same elevation of between 3250 and 3300 meters. Sawtooth Mountain to the west of that pass rises to more than 3500 meters suggesting the pass is also at least 250 meters deep. Today these passes are little more than notches carved into high mountain ridges, but the passes are water eroded features and were initially eroded by diverging south oriented flood flow channels. Beartooth Mountains uplift combined with headward erosion of the deep northeast oriented West Rosebud Creek-Rosebud Creek valley north and east of figure 5 beheaded and reversed the south oriented flood flow to erode the north oriented West Rosebud Creek valley segment seen in figure 5. Probably the reversed flood flow captured south oriented flood flow from further west (e.g. on Stillwater River alignment) and the captured flood water moved in an east, northeast, and north direction on the Goose Creek alignment to flow to the newly reversed West Rosebud Creek valley alignment and helped erode the deep north oriented West Rosebud Creek valley. Beartooth Mountains uplift continued after flood waters ceased to flow across the region and at a later time valley glaciers formed in the high mountain regions and further eroded the mountain valleys.

Detailed map of West Rosebud Creek-Zimmer Creek drainage divide area

Figure 6: Detailed map of West Rosebud Creek-Zimmer Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the West Rosebud Creek-Zimmer Creek drainage divide area seen in less detail in figure 5.  Grasshopper Glacier is located near the center of figure 6 and West Rosebud Creek flows in a north-northeast direction from the base of Grasshopper Glacier to the north edge of figure 6. South of Grasshopper Glacier and the high ridge connecting Iceberg Peak with Mount Wilse is Zimmer Lake and Zimmer Creek flows in a south direction to the south center edge of figure 6. The map contour interval for figure 6 is 40 feet and the drainage divide at the mountain pass between West Rosebud Creek and Zimmer Creek has an elevation of between 10560 and 10600 feet. Anyone who has climbed up to the pass (which I have done) knows it is a steep climb in both directions. However, Iceberg Peak to the west rises to 11,552 feet and Mount Wilse to the east rises to 11,831 feet, which suggests the pass is almost 1000 feet deep. The pass between Sawtooth Mountain and Iceberg Peak in section 17 links the south-southwest oriented Goose Creek valley with the north-northeast oriented West Rosebud Creek valley and is almost as deep. Today these high mountain passes are about the last place one would look to find evidence of diverging flood flow channels, yet the passes were initiated as deep diverging south oriented flood flow channels at a time when the Beartooth Mountains did not stand high above surrounding regions. South oriented floodwaters were carving deep flood flow channels into what was at that time a rising mountain mass. Floodwaters were moving to the actively eroding southeast oriented Clarks Fork of the Yellowstone River, which at least initially was eroding headward from south oriented flood flow channels extending southward across the Bighorn Basin and what were probably a rising Owl Creek Mountains mass. Headward erosion of the deep northeast oriented Yellowstone River valley beheaded and reversed those south oriented flood flow channels to erode the present day north oriented Bighorn River valley and the northeast and north-northeast Clarks Fork of the Yellowstone River valley segment. Subsequently headward erosion of the deep northeast oriented Rosebud Creek-West Rosebud Creek valley beheaded and reversed the south oriented flood flow routes across figure 6. Continued Beartooth Mountains uplift and alpine glaciation further modified the figure 6 landscape.

East Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area

Figure 7: East Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the East Rosebud Creek-Clarks Fork of the Yellowstone River drainage divide area south and east of figure 5 and includes overlap areas with figure 5.  Grasshopper Glacier is located near the northwest corner of figure 7 and West Rosebud Creek flows in a north-northeast direction from the base of Grasshopper Glacier to the north edge of figure 7. Colter Pass is located near the southwest corner of figure 7 and the south-southeast oriented Clarks Fork of the Yellowstone River can be seen just east of Colter Pass. Fossil Lake is near the center of figure 7 and East Rosebud Creek flows in a northeast direction from Fossil Lake to the north edge of figure 7 (near northeast corner). Note how the headwaters of northeast oriented East Rosebud Creek have several southeast oriented barbed tributaries. For example a southeast oriented stream flows from Looking Glass Lake to Fossil Lake. South of Fossil Lake is Russell Lake and the south oriented stream flowing from Russell Lake to Fox Lake is Russell Creek. Fox Lake drains in a southeast and south direction with water eventually reaching the southeast oriented Clarks Fork of the Yellowstone River. A close look at figure 7 reveals a deep through valley linking the northeast oriented East Rosebud Creek valley with the south oriented Russell Creek valley. The map contour interval for figure 7 is 50 meters and the through valley floor elevation at the drainage divide is between 3000 and 3050 meters. Mount Dewey to the east rises to 3486 meters and elevations greater than 3250 meters are seen northwest of Fossil Lake with mountains to the northwest rising to elevations greater than 3500 meters. While most of the through valley is drained today by East Rosebud Creek to the north the through valley is at least 200 meters deep and a case can be made that it once was even deeper. The through valley provides evidence of a major south oriented flood flow channel eroded into the rising Beartooth Mountains mass prior to headward erosion of the deep northeast oriented East Rosebud Creek valley, which eroded headward from the deep northeast oriented Yellowstone River valley. The deep northeast oriented Yellowstone River eroded headward from space in a deep “hole” being opened up by melting of the thick ice sheet that had once filled the deep “hole.”

Detailed map of East Rosebud Creek-Russell Creek drainage divide area

Figure 8: Detailed map of East Rosebud Creek-Russell 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 East Rosebud Creek-Russell Creek drainage divide area seen in less detail in figure 7. Fossil Lake is located near the center of figure 8 and East Rosebud Creek flows in a northeast direction from Fossil Lake to the north edge of figure 8 (east half). The Fossil Lake elevation is given as 9890 feet (the map contour interval for figure 8 is 40 feet). Note the south-southeast oriented stream flowing across the narrow section 30 to Fossil Lake. Fizzle Lake is located in section 36 west of Fossil Lake and No Bones Lake is west of Fizzle Lake. No Bones Lake drains to Fizzle Lake, which then drains in a south-southeast and south direction to the south center edge of figure 8 and south of figure 8 to Russell Lake and Russell Creek. The Fizzle Lake elevation is shown as 9818 feet, which is 72 feet lower than the nearby Fossil Lake and the two lakes are linked by a through valley, yet Fossil Lake and Fizzle Lake drain in very different directions. There are multiple through valleys linking the Fossil Lake basin with the south oriented Russell Creek headwaters with the deeper through valleys having elevations at the drainage divides of between 9920 and 9960 feet, or less than 70 feet higher than the Fossil Lake elevation. The through valleys provide evidence of flood flow channels that once crossed the region. In this case at least some southeast oriented flood flow moving towards the actively eroding southeast oriented Clarks Fork of the Yellowstone River valley (south and east of figure 8) was captured by headward erosion of the deep northeast oriented East Rosebud Creek valley. The captured floodwaters moved in an east and northeast direction across the present day Fossil Lake basin to the actively eroding East Rosebud Creek valley and helped erode the deep East Rosebud Creek valley. Note also the northwest to southeast oriented through valleys in section 32 linking the Fossil Lake basin with south oriented streams flowing to Lake of the Clouds, which drains to Russell Creek. These section 32 through valleys were eroded by southeast oriented flood flow channels prior to floodwaters in those channels being captured by headward erosion of the much deeper northeast oriented East Rosebud Creek valley. Subsequent to the end of flood flow across the region and the continuing Beartooth Mountains uplift alpine glaciers formed in the region and further modified the figure 8 landscape.

Granite Lake-Muddy Creek drainage divide area

Figure 9: Granite Lake-Muddy Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the Granite Lake-Muddy Creek drainage divide area south and east of figure 7 and includes a small overlap area with figure 7. Clarks Fork of the Yellowstone River flows in a southeast direction across the southwest quadrant of figure 9. Fox Lake (seen in figure 7 above) is located near the northwest corner of figure 9 and Russell Creek is the southwest and south oriented stream flowing to Fox Lake. Crazy Creek flows in a southeast and south direction from Fox Lake to join the southeast oriented Clarks Fork of the Yellowstone River. Granite Lake is located slightly north and east of the center of figure 9 and the southwest, south-southeast, northwest, and south oriented stream flowing from Granite Lake to Clarks Fork is Lake Creek. East of Lake Creek is south, southwest, and south oriented Muddy Creek, which is another Clarks Fork tributary and which flows along the west flank of Beartooth Butte. Beartooth Butte appears on the map to be composed of fundamentally different material than surface materials in the regions surrounding it. Using topographic map evidence alone the bedrock composition cannot be determined, although evidence from other sources indicates Beartooth Butte is an erosional remnant of sedimentary strata, which are resting on much older metamorphic and igneous bedrock. Beartooth Butte provides evidence the entire Beartooth Mountains upland region was once covered by sedimentary strata, which with the exception of Beartooth Butte have been completely eroded away. The deep erosion of the Beartooth Mountains upland surface was done by south and southeast oriented floodwaters flowing across what was a rising mountain mass. Evidence of the south and southeast oriented flood flow channels can be seen in the form of through valleys crossing various drainage divides. For example south of Granite Lake a trail follows the south-southeast oriented through valley linking the Granite Lake basin with the south oriented Muddy Creek valley. Other through valleys can be seen linking Lost Lake with the south-southeast oriented Lake Creek valley segment and the southeast oriented Lake Reno outlet stream valley with the Lily Lake basin. Figure 9 evidence reveals a complex of anastomosing flood flow channels crossing the entire map area. Floodwaters were moving to what was an actively eroding southeast oriented Clarks Fork valley, which at that time was probably eroding headward from deep south oriented flood flow channels in the Bighorn Basin and across what were probably rising Owl Creek Mountains further to the south.

Detailed map of Granite Lake-Muddy Creek drainage divide area

Figure 10: Detailed map of Granite Lake-Muddy 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 Granite Lake-Muddy Creek drainage divide area seen in less detail in figure 7 above. Beartooth Butte is the high region located along the south half of the east edge of figure 10. Granite Lake is located in the north center area of figure 10. The Granite Lake outlet is Lake Creek, which flows in a south-southwest and west direction in sections 28 and 29 before turning to flow in a south-southeast direction across section 32. Muddy Creek originates almost on the south edge of Granite Lake along the south edge of section 22 and then flows in a south-southeast direction across section 27 and into a large marshy basin in section 34. Note how the Muddy Creek valley is linked to the Granite Lake basin by a well-defined through valley. The map contour interval for figure 10 is 40 feet and the through valley floor elevation at the drainage divide is between 8680 and 8720 feet. The hill immediately to the west rises to more than 8880 feet and elevations of 9000 feet can be found in sections 33 and 34. The hill northeast of the through valley in section 22 rises more than 9400 feet, suggesting the through valley is at least 160 feet deep and may have been much deeper at one time. Note other north-northwest to south-southeast oriented through valleys crossing drainage divides. For example a through valley extends from the northeast corner of section 22 across the southwest corner of section 23 and then across section 26 before draining to a south-southwest oriented stream to reach the south oriented Muddy Creek valley. Also, in the southeast quadrant of section 22 there is an unnamed lake that drains to Muddy Creek, but which is linked by a through valley with the Granite Lake basin. There are dozens of similar through valleys crossing drainage divides in figure 10 and these through valleys provide evidence of anastomosing flood flow channels in what was once a massive south oriented anastomosing channel complex. The south oriented floodwaters stripped overlying bedrock from the figure 10 region, except at Beartooth Butte, which is a remnant of the sedimentary strata that once covered the entire figure 10 region.

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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