Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between the north oriented Stillwater River and southwest and south oriented Lamar River tributaries in the Absaroka-Beartooth Wilderness, which is located in south central Montana, north and east of the Yellowstone National Park northeast corner. The Absaroka Range straddles the Montana-Wyoming state line in the along Yellowstone National Park east boundary and the Beartooth Mountains are located directly north and east of the Yellowstone National Park northeast corner. The Yellowstone River flows in a northwest, north, and northwest direction across Yellowstone National Park near the Absaroka Range west flank. Once in Montana the Yellowstone River turns to flow in a northeast and east-southeast direction around the Absaroka Range north end and then flows in an east direction north of the Beartooth Mountains. The Lamar River is a northwest oriented tributary to the northwest oriented Yellowstone River in the Yellowstone National Park northeast quadrant and has southwest and south oriented tributaries including Soda Butte Creek and Slough Creek, which originate in high mountains where the Absaroka Range and Beartooth Mountains meet in southern Montana. The Stillwater River originates in the high mountains just north of the Soda Butte Creek headwaters and flows in a north and northeast direction to join the east-southeast oriented Yellowstone River north of the Beartooth Mountains. Through valleys (or mountain passes) eroded across high mountain ridges cross the Stillwater River-Soda Butte Creek and Stillwater River-Slough Creek drainage divides and provide evidence of multiple flood flow channels, which existed prior to crustal warping that raised the high mountain ranges and headward erosion of the deep east oriented Yellowstone River valley. Crustal warping responsible for Yellowstone Plateau and Absaroka Range and Beartooth Mountains uplift combined with headward erosion of the deep east and northeast oriented Yellowstone River valley caused massive, but gradual and systematic flood flow reversals that resulted in headward erosion of the deep north and northeast oriented Stillwater River valley and its tributary valley network. Floodwaters were derived from a rapidly melting thick North American ice sheet, which is interpreted to have caused the crustal warping. Subsequent to emergence of the Absaroka Range and Beartooth Mountains as high mountains valley glaciers formed and further eroded some high elevation valley heads.

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 Stillwater River-Lamar River drainage divide area landform origins in the Absaroka-Beartooth Wilderness in south central; 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 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 Stillwater River-Lamar River drainage divide area landform evidence in the Absaroka-Beartooth Wilderness in south central Montana will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Stillwater River-Lamar River drainage divide area location map

Figure 1: Stillwater River-Lamar 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 Stillwater River-Lamar River drainage divide in the Absaroka-Beartooth Wilderness 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 yellows shaded area straddling the south edge of figure 1 (west half). 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, Montana and then turning to flow in a northeast direction to Billings and the figure 1 north edge (near northeast corner). The Absaroka Range is located slightly east of the northwest oriented Yellowstone River segment and extends from southern Montana across the Yellowstone National Park eastern margin in south-southeast direction to beyond the figure 1 map area. The Beartooth Mountains are not labeled in figure 1, but extend eastward from the Absaroka Range along the Montana-Wyoming border to near Red Lodge, Montana. The Lamar River originates south of Indian Peak (near Yellowstone National Park east border) and flows in a northwest direction to join the Yellowstone River. The unlabeled southwest oriented stream originating in Montana and joining the Lamar River just before the Lamar River joins the Yellowstone River is Slough Creek in the northeast and Buffalo Creek in the southwest. Not shown in figure 1 is Soda Butte Creek, which originates near Cooke City, Montana and which then flows in a southwest direction to join the Lamar River. The Stillwater River is unlabeled on figure 1, but is the north-northeast and northeast oriented river originating north of Silver Gate (at Yellowstone National Park northeast corner) and flowing through Nye, Montana before joining the Yellowstone River near Columbus. The Stillwater River-Lamar River drainage divide area illustrated and discussed here is located between the north oriented Stillwater River headwaters and the south and southwest oriented Soda Butte Creek and Slough Creek headwaters in the region north of Silver Gate and Cooke City, which are located at the Yellowstone National Park northeast corner.

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 as crustal warping raised the Yellowstone Plateau area and Absaroka Range and Beartooth Mountains at approximately the same time as the deep Yellowstone River valley eroded headward from a deep “hole” in which a thick 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 deep east and northeast oriented Yellowstone River valley eroded headward across eastern and southern Montana 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 the Yellowstone Plateau and the Absaroka Range and Beartooth Mountains, did not stand high above the surrounding regions and floodwaters could freely flow across the entire figure 1 map area. Over time however uplift of the Yellowstone Plateau and of the regional mountain ranges channeled the huge south and southeast oriented melt water floods into valleys or basins between the rising mountains.

One such flood flow channel was between the rising Gallatin and Absaroka mountain ranges along the valleys now used by the northwest and north-northeast oriented Yellowstone River. Another such south oriented flood flow channel was between the Beartooth Mountains and Pryor Mountains and is now used by north-northeast oriented Clarks Fork Yellowstone River segment near Belfry, Montana (upstream from the north-northeast oriented segment the Clarks Fork Yellowstone River flows in a southeast direction). These large south oriented flood flow channels were eventually beheaded and reversed by continued crustal warping and by headward erosion of the deep northeast and east oriented Yellowstone River valley from the deep “hole” the melting ice sheet had once occupied to capture the immense melt water floods and divert the flood flow into space in the deep “hole” being opened up by the ice sheet melting. The entire Yellowstone River valley upstream from its elbow of capture (where it changes from flowing in a northwest direction to flowing in a northeast direction) was probably eroded by a massive flood flow reversal as the ongoing Yellowstone Plateau and Absaroka Range uplift continued. The north oriented Clarks Fork Yellowstone River and the Stillwater River routes were established during flood flow reversals caused by crustal warping and by headward erosion of the deep east and northeast oriented Yellowstone River valley. Headward erosion of the deep north-northeast oriented Clarks Fork Yellowstone River valley captured southeast oriented flood flow moving across what are today the high Beartooth Mountains.

Detailed location map for Stillwater River-Lamar River drainage divide area

Figure 2: Detailed location map Stillwater River-Lamar 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 Stillwater River–Lamar River drainage divide area in the Absaroka-Beartooth Wilderness. 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 north and northwest direction across the southwest corner of figure 2. The Lamar River flows in a northwest direction to join the Yellowstone River near Tower Junction, Wyoming. Buffalo Creek is a south and southwest oriented stream originating in the Absaroka Range and joining the Lamar River east of Tower Junction. North of the Buffalo Creek headwaters is the north oriented Boulder River and the Boulder River-Buffalo Creek drainage divide area essay illustrates and discusses topographic map evidence in that region. Slough Creek is a south and southwest oriented Buffalo Creek tributary. Soda Butte Creek is a southwest oriented Lamar River tributary originating near Cooke City (just east of the northeast corner of Yellowstone National Park). The Stillwater River originates just north of the Soda Butte Creek headwaters and flows in a north and north-northeast direction to the north center edge of figure 2. Clarks Fork Yellowstone River originates in the Beartooth Mountains north of Cooke City and flows in a southeast direction to the south edge of figure 2 (near southeast corner) and then in a northeast and east direction to the east edge of figure (just north of the southeast corner). Topographic maps illustrated and discussed in this essay show drainage divides between the Stillwater River and Slough Creek, Soda Butte Creek, and Clarks Fork Yellowstone River.

Stillwater River-Slough Creek drainage divide area

Figure 3: Stillwater River-Slough Creek 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-Slough Creek drainage divide area. The Stillwater River is the north oriented river located in the east half of figure 3. Wounded Man Creek is the northeast oriented tributary joining the Stillwater River near the north edge of figure 3 and has a northeast oriented South Fork and an east-northeast oriented Middle Fork, which joins a south and southeast oriented (and unlabeled) North Fork. Further south is east, northeast, and east-southeast oriented Horseshoe Creek, which joins the north oriented Stillwater River near the Stillwater-Park County line. The north and northwest oriented stream flowing to the northwest corner of figure 3 is the East Fork Boulder River. The southwest, southeast, and south oriented stream originating near Pinnacle Mountain (east of the north oriented East Fork Boulder River and flowing to the south edge of figure 3 (west half) is Slough Creek. Note how the north oriented East Fork Boulder River valley and the south oriented Slough Creek valley are linked by a deep through valley with the word “PACK” being located in that through valley. That through valley was eroded by south oriented flood flow prior to the reversal of flood flow that eroded the north oriented East Boulder River valley. Crustal warping raising the Absaroka Range and the Beartooth Mountains and headward erosion of the deep east and northeast oriented Yellowstone River valley north of figure 3 caused a gradual and systematic flood flow reversal that eroded the north oriented valleys. Wounded Man Creek (this is a second Wounded Man Creek) flows in a west and southwest direction north of Horseshoe Mountain to join south oriented Slough Creek west of Horseshoe Mountain. Note the deep west to east oriented through valley linking the west oriented Wounded Man Creek valley with the east oriented Horseshoe Creek valley. The contour interval for figure 3 is 50 meters and the through valley floor elevation at the drainage divide is between 2750 and 2800 meters. Horseshoe Mountain rises to 3092 meters while Pinnacle Mountain to the north rises much higher, meaning the through valley is approximately 300 meters deep. The through valley was probably eroded first by south oriented flood flow moving from a south oriented flood flow route on the present day Stillwater River alignment to a south oriented flood flow channel on the Slough Creek alignment. However, because headward erosion of the deep east and northeast oriented Yellowstone River valley would have beheaded and reversed south oriented flood flow on the Stillwater River alignment before beheading and reversing south oriented flood flow on the Boulder River alignment it is probable that for a time south oriented flood flow on the Boulder River alignment moved in an east direction on the Wounded Man Creek-Horseshoe Creek alignment to reach what was then a newly reversed north oriented flood flow channel on the Stillwater River alignment.

Detailed map of Horseshoe Creek-Wounded Man Creek drainage divide area

Figure 4: Detailed topographic map of the Horseshoe Creek-Wounded Man 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 Horseshoe Creek-Wounded Man Creek drainage divide area seen in less detail in figure 3 above. Horseshoe Creek originates at Lake of the Woods in section 1 and flows in an east, northeast, and east direction to the east center edge of figure 4. East of figure 4 Horseshoe Creek joins the north oriented Stillwater River with water eventually reaching the east and northeast oriented Yellowstone River near Columbus, Montana. Wounded Man Creek originates in the west half of section 1 and flows in a south direction before turning to flow in a west direction across sections 2 and 3 to the west edge of figure 4. West of figure 4 Wounded Man Creek joins south oriented Slough Creek with water reaching the northwest oriented Lamar and Yellowstone Rivers in Wyoming and after a large loop around the Absaroka Range northwest end eventually reaching the Columbus, Montana area (north and east of figure 4). Note the deep through valley (or mountain pass) linking the east and north oriented Horseshoe Creek valley with the west and south oriented Wounded Man Creek valley. The map contour interval for figure 4 is 40 feet and the through valley floor elevation at the drainage divide is between 9000 and 9040 feet. Horseshoe Mountain near the southwest corner of figure 4 has an elevation of 10,144 feet while Timberline Mountain to the north of the through valley rises to more than 10,200 feet suggesting the through valley may be as much as 1100 feet deep. The through valley is a water eroded feature and was eroded by massive south oriented flood flow at a time when the Absaroka Range and Beartooth Mountains did not stand high above surrounding regions (as they do today) and flood waters from the north could freely flow across the region. At that time the Absaroka Range and Beartooth Mountains were being uplifted and deep flood flow channels were being eroded into the rising mountain masses. Eventually uplift of the mountain masses and headward erosion of the deep east and northeast oriented Yellowstone River valley systematically reversed the south oriented flood flow, which created the Horseshoe Creek-Wounded Man Creek drainage divide seen in figure 4.

Slough Creek-Stillwater River drainage divide area south of Horseshoe Mountain

Figure 5: Slough Creek-Stillwater River drainage divide are south of Horseshoe Mountain. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Slough Creek-Stillwater River drainage divide area south of Horseshoe Mountain, south of figure 3, and includes overlap areas with figure 3. Slough Creek flows in a south direction in the west half of figure 5. Labeled Slough Creek tributaries from the east (from north to south) are Wounded Man Creek, Lake Abundance Creek, Wolverine Creek, and Lost Creek. Note how Lake Abundance Creek, Wolverine Creek, and Lost Creek have northwest oriented valley segments. Those northwest oriented valley segments were eroded by reversals of flood flow in what had been southeast oriented flood flow channels. The north oriented Stillwater River is located in the east half of figure 5 and the Stillwater River headwaters are located north of Miller Mountain near the south edge of figure 5. Note how the north oriented Stillwater headwaters valley is linked by mountain passes (or through valleys) with southeast oriented valleys in the southeast corner of figure 5. The southeast oriented valleys are better illustrated in figures 7 and 8 below and the southeast oriented valleys draining to the south edge of figure 5 drain to Soda Butte Creek while southeast oriented Fisher Creek flows to the southeast-southeast oriented Clarks Fork Yellowstone River. Note also the through valleys (or mountain passes) linking the northwest oriented Wolverine Creek valley and the west and northwest oriented Lake Abundance Creek valley with the north oriented Stillwater River valley.

The map contour interval for figure 5 is 50 meters and the through valley linking Lake Abundance Creek with the Stillwater River has an elevation at the drainage divide of between 2550 and 2600 meters. Mount Abundance to the south rises to 3083 meters while an unnamed peak to the north rises even higher suggesting the through valley is at least 500 meters deep. Wolverine Pass between Mount Abundance and Wolverine Peak to the south has an elevation at the drainage divide of between 2750 and 2800 and is approximately 300 meters deep. Flood flow movements in these through valleys was probably moving in different directions as deep valleys eroded headward into the region and at least for a time floodwaters were probably moving to the southeast oriented Clarks Fork Yellowstone River valley south and east of figure 5. Headward erosion of the south oriented Slough Creek valley for a time captured the south oriented flood flow and diverted the flood waters to a south and southeast oriented flood flow channel on the present day Lamar River alignment in Yellowstone National Park. Reversal of flood flow on the Stillwater River alignment also captured the flood flow and diverted floodwaters in a north direction to what was probably the actively eroding east and northeast oriented Yellowstone River valley in Montana. Subsequently the reversal of flood flow in the present day Boulder River drainage basin captured the southeast oriented flood flow and diverted the floodwaters in a north direction to the actively eroding Yellowstone River valley in Montana. Still later southeast oriented flood flow across the Yellowstone National Park region was reversed to flow in a northwest direction to the deep northeast, east, and northeast oriented Montana Yellowstone River valley.

Detailed map of Lake Abundance Creek-Stillwater River drainage divide area

Figure 6: Detailed map of Lake Abundance Creek-Stillwater River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 illustrates the Lake Abundance Creek-Stillwater River drainage divide area seen in less detail in figure 5. The Stillwater River flows in a north direction in the east half of figure 6 and originates near the figure 6 south edge. Lake Abundance is located in section 32 south of the north center edge of figure 6 and Lake Abundance Creek flows in a west direction from Lake Abundance across sections 31 and 36 to the northwest corner of figure 6. The map contour interval for figure 6 is 40 feet and the through valley linking Lake Abundance with the Stillwater River valley has an elevation at the drainage divide of between 8440 and 8480 feet. Mount Abundance in section 5 to the south rises to 10,116 feet and while not seen in figure 6 the mountains north of Lake Abundance rise even higher. In other words the through valley is approximately 1700 feet deep. While the map evidence suggests the through valley location is related to regional geologic units and structures, the through valley is also a water eroded feature. Wolverine Pass in section 8 south of Mount Abundance links the northwest oriented Wolverine Creek valley  (in section 7) with the north oriented Stillwater River valley. Wolverine Pass at the drainage divide has an elevation of between 9040 and 9080 feet and is more than 1000 feet deep. Both the Wolverine Pass through valley and the Lake Abundance through valley originated as flood water eroded features at a time when south oriented floodwaters were flowing across the region. At that time the Absaroka Range and Beartooth Mountains did not stand high above surrounding regions as they do today and floodwaters were able to freely flow across the region. Uplift of the mountains occurred as floodwaters were flowing across the region and at first floodwaters carved deep valleys into the rising mountain masses. Headward erosion of much deeper valleys from various directions systematically captured the floodwaters and caused significant flood flow reversals. Eventually uplift of the mountains and headward erosion of the deep east and northeast oriented Yellowstone River valley north of figure 6 ended the flood flow across the figure 6 map region. Mountain uplift probably continued and alpine glaciers subsequently eroded at least some of the high mountain areas.

Stillwater River-Soda Butte Creek drainage divide area

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

Figure 7 illustrates the Stillwater River-Soda Butte Creek drainage divide area south and east of figure 5 and includes overlap areas with figure 5. Mount Abundance is located in the northwest quadrant of figure 7 and the Stillwater River flows from just north of Miller Mountain in a north direction between Mount Abundance and Scotch Bonnet Mountain. Goose Creek is a west oriented tributary joining the Stillwater River near the north edge of figure 7. South of the Stillwater River headwaters and Miller Mountain is west-southwest oriented Soda Butte Creek, which flows from Cooke City to Silver Gate and then to the south edge of figure 7. Southeast oriented Sheep Creek and Miller Creek are tributaries to west-southwest oriented Soda Butte Creek and are barbed tributaries. East of Cooke City on the highway is Colter Pass and east of Colter Pass is the southeast oriented Clarks Fork Yellowstone River, which is formed at the confluence of southeast oriented Fisher Creek and south oriented Lady of the Lake Creek. South of Cooke City is northwest oriented Woody Creek, which flows to Soda Butte Creek. The southeast and northwest oriented valley segments seen in figure 7 are on alignments that originated as southeast oriented flood flow channels prior to headward erosion of the deep west-southwest oriented Soda Butte Creek valley. The northwest oriented Woody Creek valley was eroded by a reversal of flood flow on the northwest end of a beheaded southeast oriented flood flow channel. Note through valleys (or mountain passes or notches in mountain ridges) between the present day north oriented Stillwater River drainage basin and southeast oriented Sheep, Miller, and Fisher Creek valleys. The map contour interval for figure 7 is 50 meters. The through valley (or notch) between Sunset Peak and Miller Mountain is defined by at least four contour lines on each side. At least three contour lines on each side define other through valleys, such as Daisy Pass between Crown Butte and Scotch Bonnet Mountain. Southeast oriented flood flow channels prior to the crustal warping and the flood flow reversals responsible for creating the north oriented Stillwater River drainage basin eroded the southeast oriented through valleys (or what are today mountain passes or notches carved in the high mountain ridges).

Detailed map of Stillwater River-Miller Creek drainage divide area

Figure 8: Detailed map of Stillwater River-Miller 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 Stillwater River-Miller Creek drainage divide area seen in less detail in figure 7. The Stillwater River originates in section 10 (southwest quadrant of figure 8) and flows in a north direction through sections 9 and 4. Miller Creek (unlabeled in figure 8) originates in section 14 (along south edge of figure 8) and flows in a southeast direction to the south edge of figure 8 and then to join west-southwest oriented Soda Butte Creek as a barbed tributary. Fisher Creek originates in section 11 and flows in a southeast direction to the east edge of figure 8 and then to the southeast oriented Clarks Fork Yellowstone River. Bull of the Woods Pass is located between Miller Mountain and Crown Butte and links the north oriented Stillwater River valley with the southeast oriented Miller Creek valley. The map contour interval for figure 8 is 40 feet and Bull of the Woods Pass at the drainage divide has an elevation of between 9720 and 9760 feet. Miller Mountain and Crown Butte both rise to elevations greater than 10,200 feet suggesting Bull of the Woods Pass is at least 400 feet deep. Daisy Pass is located between Crown Butte and Chimney Rock and also has an elevation at the drainage divide of between 9720 and 9760 feet. Both Daisy Pass and Bull of the Woods Pass were eroded by southeast oriented flood flow channels, which were being carved into a rising mountain mass. At that time the southeast oriented flood flow was probably moving in a southeast direction along the Miller Creek alignment and then across what is now Colter Pass to reach what was an actively eroding southeast oriented Clarks Fork Yellowstone River valley. Headward erosion of the deep west-southwest oriented Soda Butte Creek valley captured the southeast oriented flood flow and diverted the floodwaters in a southwest direction to a deeper southeast oriented flood flow channel in present day Yellowstone National Park. Lulu Pass near the corner of sections 1, 2, 10, and 11 is another equally deep through valley linking the north oriented Stillwater River valley with the southeast oriented Fisher Creek valley, which today still drains to the southeast oriented Clarks Fork Yellowstone River valley. These three closely spaced and approximately equally deep through valleys (or mountain passes) provide evidence of multiple flood flow channels such as might be found in an anastomosing channel complex.

Detailed map of the Goose Creek-Lady of the Lake Creek drainage divide area

Figure 9: Detailed map of the Goose Creek-Lady of the Lake Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 provides a detailed topographic map of the Goose Creek-Lady of the Lake Creek drainage divide area seen in less detail in figure 7 above. Goose Creek is located in sections 34, 35, and 36 in the northwest quadrant of figure 9 and flows in a west direction to join the north oriented Stillwater River west of figure 9. Lady of the Lake is located in sections 5 and 8 in the southeast quadrant of figure 9 and Lady of the Lake Creek drains in a south direction from Lady of the Lake to the southeast oriented Clarks Fork Yellowstone River. Note near the corner of sections 1, 6, 31, and 36 a through valley linking Huckleberry Lake and Dick Lake, with Huckleberry Lake in the Goose Creek drainage basin and Dick Lake in the Lady of the Lake drainage basin. The map contour interval for figure 9 is 40 feet and the through valley floor elevation at the drainage divide is between 9520 and 9560 feet. Sheep Mountain to the south (in section 1) rises to 10,518 feet and elevations rise to more than 10,600 feet along the north edge of figure 9 (north of section 32). In other words the through valley is more than 1000 feet deep and links the north oriented Stillwater River valley with the southeast oriented Clarks Fork Yellowstone River valley. The through valley was eroded by south and southeast oriented floodwaters flowing from the present day north oriented Stillwater River drainage basin to what at that time was an actively eroding southeast oriented Clarks Fork Yellowstone River valley. At that time the Beartooth Mountains were being uplifted and floodwaters eroded the deep through valley prior to the flood flow reversal that resulted in creation of the north oriented Stillwater River drainage basin.

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

Figure 10: Detailed map of 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 10 provides a detailed topographic map of the Soda Butte Creek-Clarks Fork Yellowstone River drainage divide area seen in less detail in figure 7 above. Cooke City is located in section 25 in the southwest quadrant of figure 10. Soda Butte Creek originates near the northeast corner of section 30 and flows in west-southwest direction through Cooke City to the west edge of figure 10 (south half). Miller Creek flows in a southeast direction from the west edge of figure 10 (north half) to join west-southwest oriented Soda Butte Creek as a barbed tributary near the east edge of Cooke City. East of the Soda Butte Creek headwaters along the highway is Colter Pass and east of Colter Pass is the south-southeast oriented Clarks Fork Yellowstone River. The Broadwater River is what appears to be a wide south-southwest oriented tributary, which joins the Clarks Fork Yellowstone River near the Interpretative Center in the southeast quadrant of figure 10. The map contour interval for figure 10 is 40 feet and Colter Pass at the drainage divide has an elevation of between 8020 and 8040 feet. The mountain directly to the south reaches an elevation greater than 10,600 feet (just south of the south edge of figure 10) and as seen in figure 9 above mountains to the north rise to elevations greater than 10,600 feet. In other words an argument could be made that Colter Pass is more than 2500 feet deep. Colter Pass was carved by southeast and east oriented flood water moving to what at one time was an actively eroding southeast oriented Clarks Fork Yellowstone River valley (there is a deep southeast oriented canyon south and east of figure 10). Headward erosion of the west-southwest oriented Soda Butte Creek valley from deep southeast oriented flood flow channels in the Yellowstone National Park area to the southwest captured the southeast oriented flood flow on the Miller Creek alignment and diverted the flood water in a west-southwest and southwest direction and created the drainage divide at Colter Pass. Since that time the region has probably been significantly uplifted and alpine glaciation may have slightly modified some landscape features.

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.