Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between the Yellowstone River and the Lamar River in Yellowstone National Park, northwest Wyoming and is located north of Yellowstone Lake. Specimen Ridge and the Mirror Plateau are located between the north-northwest, northeast, north, and northwest Yellowstone River and the north-northwest and northwest oriented Lamar River, which flows to the north and northwest oriented Yellowstone River. North and northeast oriented Lamar River tributary valleys are linked by through valleys or passes with southwest oriented valleys draining to northwest oriented Yellowstone River tributaries and to valleys of southwest and south oriented streams draining to Yellowstone Lake. North and northwest oriented Yellowstone River tributary valleys are also linked by through valleys with south and southwest oriented streams flowing to Yellowstone Lake. South oriented drainage systems flowing to Yellowstone Lake, barbed tributaries, elbows of capture, and the through valleys are interpreted in the context of diverging and converging south oriented flood flow channels that once crossed the region. Floodwaters are interpreted to have been derived from the western margin of a melting thick North American ice sheet and were flowing from western Canada to and across the study region. At that time ice sheet related crustal warping was beginning to raise the Yellowstone Plateau and adjacent mountain ranges and at least initially immense south and southeast oriented melt water floods could freely flow to and across the study region. As crustal warping raised the region and as deep northeast oriented valleys eroded headward from space in the ice sheet created deep “hole” being opened up by ice sheet melting flood flow reversals occurred which gradually and systematically created the north oriented Yellowstone River and Lamar drainage systems seen today. South oriented drainage routes to Yellowstone Lake and elsewhere in the study region provide evidence of the south oriented diverging and converging flood flow channels that crossed the region prior to the gradual and systematic flood flow reversals.

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 Yellowstone River-Lamar River drainage divide area landform origins in Yellowstone National Park, northwest 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 Yellowstone River-Lamar River drainage divide area landform evidence in Yellowstone National Park, northwest Wyoming will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Yellowstone River-Lamar River drainage divide area location map

Figure 1: Yellowstone 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 Yellowstone River-Lamar River drainage divide area in Yellowstone National Park, northwest Wyoming and shows a region in northwest Wyoming with southern Montana seen in the northern quarter of figure 1. Yellowstone National Park is located in the northwest corner of Wyoming and is shown and labeled in the west half of figure 1. The Yellowstone River flows in a north direction from the south edge of figure 1 to Yellowstone Lake. From Yellowstone Lake the Yellowstone River flows in a northwest direction to Canyon, Wyoming and then in a northeast, north, and northwest direction to Gardiner, Montana. From Gardiner the Yellowstone River flows in a northwest and northeast direction to the north edge of figure 1 (west half). The unlabeled south, southwest, and west oriented stream flowing to the Yellowstone River at Fishing Bridge is Pelican Creek. The Lamar River originates near the Yellowstone National Park east boundary and flows in a west, southwest and then northwest direction to join the Yellowstone River at the point where the Yellowstone River turns from flowing in a north direction to flowing in a northwest direction. The Yellowstone River-Lamar River drainage divide area investigated in this essay is located north of Yellowstone Lake, east of the Yellowstone River, south and west of the Lamar River, and includes the Pelican Creek drainage basin.

A brief look at the big picture erosion history will help in understanding the interpretation used, which is the figure 1 drainage routes developed as immense south and southeast oriented melt water floods flowed across the region. Floodwaters were derived from the western margin of a thick North American ice sheet and were flowing in south and southeast directions from western Canada across Montana to and across the region seen in figure 1. As the south and southeast oriented floodwaters were flowing across Montana the deep northeast oriented Yellowstone River valley (north of figure 1) eroded headward from the deep “hole” in which the large ice sheet was rapidly melting. The deep “hole” was created by deep glacial erosion under the ice sheet and by crustal warping that raised the Yellowstone Plateau and adjacent mountain ranges as floodwaters flowed across the region. 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 eroded headward from the deep “hole” to capture the immense south and southeast oriented ice marginal floods flowing from western Canada across Montana. At that time mountain ranges and Yellowstone Plateau seen in the figure 1 map area did not stand high above regions to the north and south and southeast oriented and floodwaters could freely flow to and across the entire figure 1 map area. Headward erosion of the much deeper east and northeast oriented Yellowstone River valley north of figure 1 beheaded the south and southeast oriented flood flow channels flowing to and across the region seen in figure 1. Floodwaters on north and northwest ends of beheaded flood flow channels reversed flow direction to create north and northwest oriented drainage routes. This brief description paints a generalized picture and the actual events were much more complicated with ever-changing anastomosing channels being captured and beheaded by headward erosion of deeper flood flow channels and/or by headward erosion of valleys from deeper flood flow channels as crustal warping raised the region and adjacent mountain ranges and as the much deeper Yellowstone River valley eroded headward from space in the deep “hole” being opened up by the melting ice sheet. Each valley segment records a capture event, many of which involved local flood flow reversals.

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

Figure 2: Detailed location map for the Yellowstone 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 Yellowstone River–Lamar River drainage divide area in Yellowstone National Park. Green areas in the east half of figure 2 are National Forest lands east of Yellowstone National Park. Stevenson Island near the south edge of figure 2 is located in the northernmost arm of Yellowstone Lake. The Yellowstone River flows in a northwest direction from Fishing Bridge on the Yellowstone Lake north shore to Canyon and then turns to flow in a northeast and north-northwest direction to Tower Junction and finally flows in a northwest direction to the north edge of figure 2 (west half). The Lamar River originates in the Yellowstone National Park easternmost extension (the Park boundary in that region is defined by the Lamar River drainage basin) and flows in a west, southwest, and west direction before turning to flow in a north-northwest and northwest direction to join the Yellowstone River slightly north of Tower Junction. Other named Yellowstone River tributaries west and south of the Yellowstone River are northwest and southwest Sour Creek, north-northwest oriented Broad Creek, northwest oriented Shallow Creek, and southwest and northwest oriented Deep Creek. South-southeast, southwest, west, and south oriented Raven Creek appears to flow to Yellowstone Lake near Fishing Bridge, but really flows in a south and southwest direction to join south, southwest, west, and south oriented Pelican Creek (unnamed in figure 2). Named Lamar River tributaries flowing from south and west of the Lamar River include northeast oriented Mist Creek and its northeast oriented tributary, Cold Creek. While the vast majority of drainage routes seen in figure 2 are oriented in north directions there are some oriented drainage routes or segments of south oriented drainage routes also present. Note south and southwest oriented Raven Creek, the southwest oriented Sour Creek segment, the southwest oriented Deep Creek headwaters, and the southeast oriented headwaters of a northeast oriented Lamar River tributary. These south oriented streams in what is today a dominantly north oriented drainage basin provide evidence of former south oriented drainage routes. The south oriented drainage routes are today linked by through valleys (or mountain passes) with north oriented drainage routes seen on the topographic maps. The through valleys provide evidence of former drainage routes and paint a picture on detailed topographic maps of diverging and converging flood flow channels, which were eroded into a surface now preserved, if it is preserved at all, by the highest mountain ridges seen in the map area shown in figure 2.

Lamar River-Wrong Creek drainage divide area

Figure 3: Lamar River-Wrong 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 Lamar River-Wrong Creek drainage divide area. The Yellowstone River can be seen flowing in a north direction along and across the west edge of figure 3. Broad Creek is the north and west-northwest oriented Yellowstone River tributary in the southwest corner of figure 3. Shallow Creek is a north-northwest and northwest oriented Broad Creek tributary and Wrong Creek is a northwest oriented Shallow Creek tributary. North of Wrong Creek and Shallow Creek is southwest and northwest oriented Deep Creek and its northwest and north-northwest tributary, Burnt Creek. The Lamar River (labeled “River” in figure 3) flows in northwest direction from the south edge of figure 3 (near southeast corner) to the north edge of figure 3 and joins the Yellowstone River north and east of figure 3. Specimen Ridge and Mirror Plateau form the Lamar River-Yellowstone River drainage divide. Lamar River tributaries flowing from the Specimen Ridge-Mirror Plateau drainage divide include Amethyst Creek, Chalcedony Creek, Unnamed Creek, Opal Creek, and Flint Creek.  While the Specimen Ridge-Mirror Plateau drainage divide forms a high ridge the top is not even, but is crossed by shallow through valleys linking the north and northeast oriented Lamar River tributary valleys with the northwest oriented Yellowstone River tributary valleys. The map contour interval for figure 3 is 50 meters and some of the through valleys are defined by two or more contour lines on a side. The through valleys were eroded by south and southwest oriented flood flow channels moving floodwaters to a south oriented flood flow to the Yellowstone Lake region located south of figure 3. At that time the deep northwest oriented Lamar River valley did not exists and the Yellowstone Plateau and regional mountains did not stand high above the surrounding area. Yellowstone Plateau and regional mountain range uplift occurred as floodwaters were flowing across them. Northwest oriented Yellowstone River tributary drainage routes were established by reversals of flood flow on southeast and south oriented flood flow channels beheaded by headward erosion of a much deeper valley on the present day Yellowstone River alignment. North and northeast oriented Lamar River tributary drainage routes were established first as south and southwest oriented flood flow channels, which had converged with the southeast south oriented flood flow channels south and west of the present day Specimen Ridge-Mirror Plateau drainage divide and then which had been beheaded by headward erosion of a much deeper valley on the present day northwest oriented Lamar River alignment. South oriented flood flow across the region ended when headward erosion of the much deeper Yellowstone River valley in eastern and southern Montana (north of figure 3) beheaded and reversed the south oriented flood flow channels and created the present day north oriented Yellowstone River drainage system.

Detailed map of Opal Creek-Deep Creek drainage divide area

Figure 4: Detailed topographic map of the Opal Creek-Deep 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 Opal Creek-Deep Creek drainage divide area seen in less detail in figure 3 above. The northwest oriented Lamar River can just barely be seen in the northeast corner of figure 4 and north and west of figure 4 joins the northwest oriented Yellowstone River. Opal Creek flows in a north and north-northeast direction from near the center of figure 4 to the north edge of figure 4 (east of center) and north of figure 4 joins the northwest oriented Lamar River. An unnamed tributary flows in a northeast direction from the Mirror Plateau to join the Lamar River near the northeast corner of figure 4 and Flint Creek flows in a northeast direction across the southeast corner of figure 4 and joins the Lamar River west of figure 4. Wrong Creek flows in a northwest direction across the southwest corner of figure 4 and west of figure 4 joins northwest oriented Shallow Creek, which then joins west-northwest oriented Broad Creek, which flows to the north oriented Yellowstone River. Deep Creek originates on the Mirror Plateau (near center of figure 4) and flows in a southwest and northwest direction to the west center of figure 4 and then to the Yellowstone River. Note the northeast-to-southwest oriented through valley eroded across the Mirror Plateau linking the north-northeast oriented Opal Creek valley with the southwest oriented Deep Creek headwaters. The map contour interval for figure 4 is 40 feet and the through valley elevation at the drainage divide is between 9000 and 9040 feet. Elevations on the Mirror Plateau to the southeast rise to 9194 feet and to the northwest elevations rise to 9474 feet. These elevations suggest the through valley is at least 150 feet deep. While not deep compared to the adjacent valleys the through valley is a water-eroded feature and was eroded as a south and southwest oriented flood flow channel at a time when the adjacent deep valleys did not exist. Floodwaters were probably converging with a southeast oriented flood flow channel on the present day northwest oriented Deep Creek alignment. Headward erosion of what was probably a much deeper south oriented valley on the present day north oriented Yellowstone River alignment beheaded the southeast oriented flood flow channel. Floodwaters on the northwest end of the beheaded flood flow channel reversed flow direction to create the northwest oriented Deep Creek drainage route segment. Headward erosion of what was probably a much deeper southeast oriented flood flow channel on the present day northwest oriented Lamar River alignment beheaded and reversed the south and southwest oriented flood flow channel across the present day Mirror Plateau and created the north oriented Opal Creek drainage route.

Yellowstone River-Pelican Creek drainage divide area

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

Figure 5 illustrates the Yellowstone River-Pelican Creek drainage divide area south and west of figure 3 and includes overlap areas with figure 3. The Yellowstone River flows in north-northwest direction from the south edge of figure 5 (west half) and then turns to flow in a northeast direction in the Grand Canyon of the Yellowstone to the north center edge of figure 5. North of figure 5 the Yellowstone River turns to flow in a north and then a northwest direction into southern Montana. Wrong Creek flows in a northwest direction from the east edge of figure 5 (north half) to join north and northwest oriented Shallow Creek, which joins north, northwest, and north oriented Broad Creek near the north edge of figure 5 (east of center). Sour Creek flows in a northwest direction from the south edge of figure 5 (east of center) and then turns in a southwest direction to join the north-northwest oriented Yellowstone River as a barbed tributary. Pelican Creek flows in a southwest and south direction from the east center edge of figure 5 to the south edge of figure 5 (near southeast corner) and south of figure 5 flows in a south, southwest, west, and south direction to Yellowstone Lake. Note how the south oriented Pelican Creek valley is located only a short distance east of the north oriented Broad Creek headwaters valley. Also note through valleys linking the Pelican Creek, Broad Creek, and Shallow Creek valleys. For example east of Fern Lake (in southeast quadrant of figure 5) a northwest-to-southeast oriented through valley links the north and northwest oriented Broad Creek valley with the south oriented Pelican Creek valley. The map contour interval for figure 5 is 50 meters and the through valley floor elevation at the drainage divide is between 2450 and 2500 meters. To the south the drainage divide rises to more than 2700 meters suggesting the through valley is at least 200 meters deep (higher elevations are found to the north meaning the valley may be even deeper). The through valley is a water-eroded valley and was eroded by a southeast oriented flood flow channel diverging from a southeast and south oriented flood flow channel on the present day north and northwest oriented Broad Creek alignment and converging with a south oriented flood flow channel on the south oriented Pelican Creek alignment. Flood flow in the flood flow channel on the Broad Creek alignment was beheaded and reversed by headward erosion of a much deeper valley on the present day Yellowstone River alignment to create the north oriented Broad Creek drainage route and Broad Creek-Pelican Creek drainage divide. Figure 6 uses a detailed topographic map to illustrate this and other through valleys linking Broad, Shallow, and Pelican Creeks.

Detailed map of Shallow Creek-Pelican Creek drainage divide area

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

Figure 6 illustrates the Shallow Creek-Pelican Creek drainage divide area seen in less detail in figure 5. Broad Creek flows from the south edge of figure 6 (west of center) in a north, west, and northwest direction to the northwest corner of figure 6 and north and west of figure 6 flows in a north and west-northwest direction to the north oriented Yellowstone River. Shallow Creek originates at Wapiti Lake (west of north center area of figure 6) and flows in a north-northeast and northwest direction to the north edge of figure 6 (west of center) and north of figure 6 flows in a northwest direction to join Broad Creek. Pelican Creek flows in a west-southwest direction from the east edge of figure 6 (north of center) and then turns to flow in a south direction to the south center edge of figure 6. South of figure 6 Pelican Creek flows in a south, southwest, west, and south direction to Yellowstone Lake. Note in the north center area of figure 6 the north-northeast oriented through valley linking a northwest oriented Shallow Creek tributary with a northwest, southwest, southeast, and southwest oriented Broad Creek tributary. The map contour interval for figure 6 is 20 feet in the west and 20 feet in the east and the through valley floor elevation at the drainage divide is between 8400 and 8440 feet. Elevations greater than 8800 feet can be found both east and west of the through valley suggesting the through valley is at least 350 feet deep. Also note south of Wapiti Lake a through valley linking the north oriented Shallow Creek valley with north and west oriented Broad Creek valley. The through valley floor elevation at the drainage divide is between 8420 and 8440 feet suggesting the through valley is approximately 350 feet deep. Diverging south oriented flood flow channels eroded these through valleys with the eastern flood flow channel moving floodwaters to the south oriented flood flow channel on the present day north oriented Broad Creek headwaters alignment. Near the south edge of figure 6, east of Fern Lake, is the through valley linking the north oriented Broad Creek valley with the south oriented Pelican Creek valley, which was seen in less detail in figure 5. The through valley floor elevation at the drainage divide is 8218 feet. South of figure 6 elevations along the Broad Creek-Pelican Creek drainage divide rise to 8796 feet suggesting through valley is more than 500 feet deep. Southeast oriented flood flow diverging from a south oriented flood flow channel on the present day north oriented Broad Creek alignment moved to a south oriented flood flow channel on the Pelican Creek alignment and later southwest oriented flood flow on the Pelican Creek alignment flowed to the south oriented flood flow channel on the Broad Creek alignment. Study of the figure 6 map area reveals even more complex flood flow movements as floodwaters first moved one way and later in a different way and then were reversed completely in the Broad Creek valley, but not in the Pelican Creek valley.

Lamar River-Raven Creek drainage divide area

Figure 7: Detailed map of Lamar River-Raven Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the Lamar River-Raven Creek drainage divide area east and slightly south of figure 5 and includes overlap areas with figure 5. The Lamar River flows in a northwest and north-northwest direction from the east edge of figure 7 (south of center) to the north edge of figure 7 (east half). Mist Creek is a northeast and north oriented Lamar River tributary flowing from the south center edge of figure 7. Other northeast and north oriented Lamar River tributaries include Willow Creek and Timothy Creek with its Buffalo Fork (its Mirror Fork is oriented in an east and south-southeast direction). Just west of the Timothy Creek headwaters near the center of figure 7 are headwaters of Raven Creek, which flows in a south and southwest direction to the south edge of figure 7 (west of center). South of figure 7 Raven Creek joins south, southwest, west, and south oriented Pelican Creek, which flows to Yellowstone Lake. Pelican Creek originates north of the Raven Creek headwaters and flows in a northwest, southwest, and south direction to the south edge of figure 7 (just west of Raven Creek). White Lake in the southwest quadrant of figure 7 is the origin of north and northwest oriented Broad Creek, which flows to the west edge of figure 7 (near northwest corner) and then to join the north and northwest oriented Yellowstone River. Note how Broad Creek flows in a north direction only a short distance from Pelican Creek, which flows on a parallel route although in a south direction. South of White Lake are headwaters of south oriented Astringent Creek, which is a Pelican Creek tributary. Note how through valleys link north oriented drainage routes with south oriented drainage routes. For example, south of White Lake a north-to-south oriented through valley links the north oriented Broad Creek valley with the south oriented Astringent Creek valley. The map contour interval for figure 7 is 50 meters and the through valley floor elevation at the drainage divide is between 2450 and 2500 meters. Elevations to the east rise to 2839 meters at Pelican Cone while Stonetop Mountain to the west rises to 2756 meters suggesting the through valley may be as much as 250 meters deep. Another through valley links the northwest oriented Pelican Creek headwaters valley with the south oriented Raven Creek valley. Still other through valleys link the north-northeast oriented Willow Creek, Buffalo Fork, and Timothy Creek valleys with the south and southwest oriented Raven Creek valley. These through valleys provide evidence of diverging and converging south oriented flood flow channels that once crossed the region. Since that time the region has been uplifted and drainage in the major valleys has been reversed to create the north oriented drainage systems seen today. However, the through valleys and south oriented drainage routes seen in figure 7 are relics of the south oriented flood flow channels that once crossed the region.

Detailed map of Lamar River-Raven Creek drainage divide area

Figure 8: Detailed map of Lamar River-Raven 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 Lamar River-Raven Creek drainage divide area seen in less detail in figure 7. The Lamar River flows in a northwest direction in the northeast corner of figure 8. Mist Creek is the northeast and north oriented tributary flowing from the south edge of figure 8 to join the Lamar River near the northeast corner of figure 8. Raven Creek flows in a south-southeast and southwest direction from the west edge of figure 8 (near northwest corner) to the southwest corner of figure 8 and south and west of figure 8 joins south, southwest, west, and south oriented Pelican Creek, which flows to Yellowstone Lake. Buffalo Fork originates in the southwest quadrant of figure 8 (just east of the Raven Creek turn to flow in a southwest direction) and flows in a north and north-northeast direction to the north edge of figure 8 (west of center) and then to join northeast oriented Timothy Creek, which joins the northwest oriented Lamar River. Willow Creek originates just east of the Buffalo Fork headwaters and flows in a north-northeast direction to the north center edge of figure 8 and north of figure 8 joins the northwest oriented Lamar River. Note how the north-northeast oriented Willow Creek valley is linked by a through valley (now crossed by north oriented Buffalo Fork) with the southwest oriented Raven Creek valley. The map contour interval is 40 feet and the through valley floor elevation at the Buffalo Fork-Willow Creek drainage divide is between 8320 and 8360 feet and at the Buffalo Fork-Raven Creek drainage divide is between 8280 and 8320 feet. Elevations to the southeast rise to 9331 feet and to the north to 8803 feet (even higher north of figure 8). These elevations suggest the through valley is at least 400 feet deep. The through valley was eroded by a south-southwest oriented flood flow channel prior to the reversal of flood flow that created the north-northeast oriented Willow Creek drainage route. South-southwest and south-southeast oriented flood flow channels on the Buffalo Fork and Raven Creek alignments converged with the south-southwest oriented flood flow channel on the Willow Creek alignment in the southwest quadrant of figure 8 with floodwaters flowing to what is today the southwest oriented Pelican Valley. Note also Lovely Pass on the drainage divide between the north-northeast oriented Willow Creek headwaters and northeast oriented Mist Creek. The elevation of the Lovely Pass floor at the drainage divide is between 8720 and 8760 feet. The drainage divide to the northeast rises to more than 9360 feet and to the southwest to 9331 feet suggesting Lovely Pass is approximately 570 feet deep. Lovely Pass was eroded by a southeast oriented flood flow channel prior to headward erosion of the deeper south-southwest oriented flood flow channel on the present day north-northeast oriented Willow Creek alignment and provides evidence of a complex erosion history as headward erosion of deeper and deeper flood flow channels captured floodwaters from less deep flood flow channels and removed tremendous amounts of material from what was probably a rising Yellowstone Plateau region.

Cold Creek-Yellowstone Lake drainage divide area

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

Figure 9 provides a topographic map of the Cold Creek-Yellowstone Lake drainage divide area south and west of figure 7 and includes overlap areas with figure 7. Yellowstone Lake is located in the southwest corner of figure 9. Pelican Creek flows in a south direction from the north edge of figure 9 (west of center) to the Pelican Valley and then flows in a southwest, west, and south direction to enter Yellowstone Lake near the west edge of figure 9. Astringent Creek is the south oriented stream flowing to the Pelican Valley just west of south oriented Pelican Creek. Raven Creek flows in a south and southwest direction to join Pelican Creek at the point where Pelican Creek turns to flow in a southwest direction. Mist Creek is the northeast oriented stream flowing from near Mist Creek Pass to the northeast corner of figure 9 and then to the north-northwest oriented Lamar River. Cold Creek is a northeast and north-northeast oriented tributary joining Mist Creek near the northeast corner of figure 9. East-northeast oriented Jones Creek in the southeast quadrant of figure 9 flows to the Shoshone River east of figure 9 with the Shoshone River flowing to the north oriented Bighorn River, which eventually joins the northeast oriented Yellowstone River (north and east of figure 9). As described in previous figures the south oriented valleys seen in figure 9 originated as south oriented flood flow channels prior to being beheaded by headward erosion of a much deeper valley on the present day north-northwest and northwest oriented Lamar River alignment. Floodwaters flowed south from the Yellowstone Lake area to the south oriented Snake River drainage basin located south of Yellowstone Lake. See Yellowstone River-Snake River drainage divide area along continental divide in Yellowstone National Park and the Yellowstone River-Pacific Creek drainage divide area south of Yellowstone National Park essays. Mist Creek Pass is another northeast-to-southwest oriented through valley linking a north oriented drainage route with a southwest oriented drainage route. The map contour interval for figure 9 is 50 meters and the Must Creek Pass elevation at the drainage divide is between 2600 and 2650 meters. Elevations north of the Mist Creek headwaters valley rise to 2865 meters and Cathedral Peak to the south rises much higher suggesting Mist Creek Pass is at least 200 meters deep. South of Mist Creek Pass is an unnamed pass linking the northeast oriented Cold Creek valley with a northwest oriented Pelican Creek tributary valley. The floor elevation of this unnamed pass at the drainage divide is also between 2600 and 2650 meters and the elevations between the unnamed pass and Mist Creek Pass rise to more than 2850 meters suggesting the unnamed pass is also approximately 200 meters deep. These passes were eroded by southwest oriented flood flow moving to the present day Yellowstone Lake basin and then to the Snake River drainage basin. Whether the present day Snake River drainage area south of Yellowstone National Park at that time drained to Pacific Ocean via the Columbia River cannot be determined from evidence in the Yellowstone National Park region and it is possible and probable floodwaters initially flowed in quite different directions.

Detailed map of Cold Creek-Pelican Creek drainage divide area

Figure 10: Detailed map of Cold Creek-Pelican 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 Cold Creek-Pelican Creek drainage divide area seen in less detail in figure 9 above. Pelican Creek flows in a south direction from the north edge of figure 10 (west half) and then turns to flow in a southwest direction through the Pelican Valley to the west center edge of figure 10. West of figure 10 Pelican Creek flows in a west and south direction to enter Yellowstone Lake, which is drained by the north oriented Yellowstone River. Raven Creek is the southwest oriented stream flowing from the north edge of figure 10 (west of center) to join Pelican Creek at the point where Pelican Creek turns to flow in a southwest direction. Astringent Creek is the south oriented stream flowing from the northwest corner of figure 10 to join southwest oriented Pelican Creek. Mist Creek flows in a north and northeast direction to the north edge of figure 10 (east half) and north and east of figure 10 Mist Creek joins the northwest oriented Lamar River, which north and west of figure 10 joins the north oriented Yellowstone River. Note the location of Mist Creek Pass just west of the elbow of capture where Mist Creek turns from flowing in a north direction to flowing in a northeast direction. Cold Creek flows in a north and north-northeast direction to the east edge of figure 10 (north half) and east and north of figure 10 joins Mist Creek. Note how a through valley links the north-northeast oriented Cold Creek valley with west-southwest and northwest oriented Pelican Creek tributary valley. The map contour interval for figure 10 is 40 feet and through valley floor elevation at the drainage divide is between 8600 and 8640 feet. Elevations north of the through valley (and south of Mist Creek Pass) rise to more than 9400 feet while elevations south of the through valley rise much higher suggesting the through valley is at least 760 feet deep. The through valley is a water-eroded valley and was eroded by southwest oriented flood flow moving to the Yellowstone Lake location and then south to what is now the Snake River drainage basin. Crustal warping that raised the region combined with headward erosion of a much deeper valley on the present day northwest oriented Lamar River alignment resulted in a flood flow reversal that created the north-northeast oriented Cold Creek drainage route and the Cold Creek-Pelican Creek drainage divide seen today.

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.