Bull Lake Creek-New Fork River drainage divide area landform origins along the continental divide in the Wyoming Wind River Range, Wyoming, USA

Authors

 

Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between Bull Lake Creek and the New Fork River along the continental divide in the Wyoming Wind River Range. Bull Lake Creek headwaters originate along the continental divide and flow in north, northeast, east, and southeast directions to join northeast oriented Bull Lake Creek, which then flows to the southeast oriented Wind River with water eventually reaching the Gulf of Mexico. South and west of the Bull Lake Creek headwaters and of the continental divide are headwaters of southwest, south-southwest, and west and south oriented tributaries to the southeast and southwest oriented New Fork River, which flows to the south oriented Green River with water eventually reaching the Pacific Ocean. The Bull Lake Creek-New Fork River drainage divide is crossed by deep passes or through valleys linking Bull Lake Creek headwaters valleys with New Fork River headwaters valleys. Most valleys in the drainage divide area have been glaciated and glaciers still fill several of the valley head areas. However, the glaciation that filled the valleys is interpreted to have occurred after immense south oriented floods initially eroded the valleys. At the time floodwaters crossed the Wind River Range the Wind River Range had not emerged as a high mountain range. Floodwaters were derived from the western margin of a thick North American ice sheet and were flowing from western Canada to and across Wyoming. The Wind River Range and other regional mountain ranges emerged as floodwaters deeply eroded surrounding basins and valleys and as ice sheet related crustal warping raised the mountain ranges. Glaciation in the Wind River Range did not occur until after all flood flow had ended and after the Wind River Range had emerged as a high mountain range. Topographic map evidence supporting the flood origin of valleys in the high Wind River Range include valley orientations and through valleys or passes crossing present day drainage divides. The through valleys or passes when used to link present day drainage routes can be used to describe south oriented anastomosing channel complexes that once crossed what is today the high Wind River Range. Floodwaters were flowing to the south oriented Green River valley and its tributary valleys and were systematically beheaded by headward erosion of the Bull Lake Creek headwaters valleys, which had eroded headward from the actively eroding southeast oriented Wind River valley. Floodwaters on north ends of beheaded flood flow routes reversed flow direction to create north oriented drainage routes. Ice sheet related crustal warping that occurred as floodwaters were being captured and reversed greatly aided in the flood flow capture and reversal processes. Wind River Range glaciation subsequently deepened and otherwise altered many of the flood-eroded valleys, although the glaciation probably did not erode new valleys.

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 Bull Lake Creek-New Fork River drainage divide area landform origins along the continental divide in the Wyoming Wind River Range, 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 Bull Lake Creek-New Fork River drainage divide area landform evidence along the continental divide in the Wyoming Wind River Range will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Bull Lake Creek-New Fork River drainage divide area location map

Figure 1: Bull Lake Creek-New Fork 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 Bull Lake Creek-New Fork River drainage divide area along the continental divide in the Wyoming Wind River Range and illustrates a region in western Wyoming. The Idaho-Wyoming state line is located along the west edge of figure 1. Grand Teton National Park is located near the northwest corner of figure 1. The Snake River flows in a south direction from Grand Teton National Park to the Wyoming Range north end and then turns in a west direction to cross the west center edge of figure 1. West of figure 1 the Snake River turns to flow in a northwest direction with water eventually reaching the Columbia River and the Pacific Ocean. Togwotee Pass is located east of Grand Teton National Park. The Wind River originates near Togwotee Pass and flows in a southeast direction between the Wind River Range and Owl Creek Mountains to Riverton in the Wind River Basin. At Riverton the Wind River turns to flow in a northeast and north direction across the Owl Creek Mountains east end (north of Boysen Reservoir) and to enter the Bighorn Basin near Thermopolis. Once in the Bighorn Basin the Wind River name changes to become the Bighorn River, which then flows in a north direction and north of figure 1 enters Montana where it joins the northeast oriented Yellowstone River with water eventually reaching the Gulf of Mexico. Bull Lake Creek is not labeled in figure 1, but is the east-northeast oriented stream originating in the Wind River Range and flowing to and through Bull Lake (which is labeled) to join the southeast oriented Wind River. Not seen in figure 1 are the north oriented South Fork Bull Lake Creek, northeast oriented Middle Fork Bull Lake Creek, northeast, east, and southeast oriented North Fork Bull Lake Creek, all three of which originate near the east-west continental divide along the Wind River Range crest. Union Pass is located near the Wind River Range northwest end. The Green River originates south of Union Pass and after flowing in a northwest direction turns to flow in a south direction to Big Piney and the south edge of figure 1 (west half). South of figure 1 Green River water eventually reaches the Colorado River and the Pacific Ocean. The New Fork River is a Green River tributary and flows in a south-southeast direction to Pinedale and Boulder before turning to flow in a southwest direction to join the Green River near Big Piney. New Fork River headwaters and tributaries originate along and near the east-west continental divide, which is located along the Wind River Range crest, and flow in southwest and west directions to join the south-southeast oriented New Fork River. The Bull Lake Creek-New Fork River drainage divide area along the east-west continental is located between the headwaters of the North, Middle, and South Forks of Bull Lake Creek and headwaters of southwest and west oriented New Fork River tributaries and is located along the Wind River Range crest.

Western Wyoming drainage routes developed during immense south oriented melt water floods as the regional mountain ranges emerged. Floodwaters were derived from the western margin of a thick North American ice sheet and were flowing from western Canada to and across western Wyoming. At first floodwaters freely flowed across the emerging Wyoming mountain ranges, including the Wind River Range, to reach the actively eroding Colorado River valley south of figure 1. The south oriented Green River valley and tributary valleys eroded headward from the deep Colorado River valley into Wyoming along south oriented flood flow channels and eroded the southwest flank of the emerging Wind River Range. Further east a major south oriented flood flow channel developed on the alignment of the present day north oriented Wind-Bighorn River and continued in a south direction east of the emerging Wind River Range to reach the deep Colorado River valley. Flood flow on this Wind-Bighorn River flood flow channel was beheaded and reversed by headward erosion of the much deeper Yellowstone River valley. Ice sheet related crustal warping combined with deep glacial erosion created a deep “hole” in which the ice sheet was located. The deep northeast oriented Yellowstone River valley eroded headward across Montana from space at the south end of the deep “hole” being opened up by ice sheet melting and at least at first being drained in a south direction across eastern Nebraska. When beheaded by headward erosion of the deep Yellowstone River valley floodwaters on the north end of the Wind-Bighorn River flood flow channel reversed flow direction to flow in a north direction to the much deeper northeast oriented Yellowstone River valley and to create the north oriented Wind-Bighorn River drainage route. The southeast oriented Wind River valley between the emerging Owl Creek Mountains and Wind River Range and its northeast and east oriented tributary valleys then eroded headward from this newly formed and much deeper north oriented Wind-Bighorn River drainage route to capture flood flow still moving in a south direction west of the Wind-Bighorn River drainage route. Headward erosion of the deep southeast oriented Wind River valley and its tributary valleys in a progressive sequence captured the south oriented flood flow channels crossing the emerging Wind River Range and diverted floodwaters to the newly formed north oriented Wind-Bighorn River drainage route. At the same time floodwaters deeply eroded the Wind River Basin and the Wind River Range northeast flank. As these flood flow capture and reversal events were occurring ice sheet related crustal warping was raising the mountain ranges relative to adjacent basins and valleys. The crustal warping greatly aided the flood flow reversal process and also played a significant role in many flood flow capture events. Following the end of south oriented flood flow across the region and after the Wind River Range had fully emerged as the high mountain range it is today the Wind River Range crest region was glaciated with valley glaciers forming in many of the flood-eroded valleys. Lakes seen along the Wind River Range flanks were formed during this much later glaciation event.

Detailed location map for Bull Lake Creek-New Fork River drainage divide area

Figure 2: Detailed location map Bull Lake Creek-New Fork 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 Bull Lake Creek-New Fork River drainage divide area along the continental divide in the Wyoming Wind River Range. Green colored areas are National Forest lands, most which are located in the Wind River Range. The brown colored areas are Wind River Indian Reservation lands. The Wind River Range extends in a north-northwest to south-southeast direction across figure 2 and the east-west continental divide is shown with a line extending from the north edge of figure 2 (near Gannett Peak-west of center) to the south edge of figure 2 (near southeast corner). Bull Lake is located in the northeast corner of figure 2 and Bull Lake Creek flows in a northeast direction to Bull Lake. North and east of figure 2 Bull Lake Creek flows to the southeast and north oriented Wind River. Three major Bull Lake Creek Forks originate near the continental divide and then flow to northeast oriented Bull Lake Creek. The South Fork Bull Lake Creek originates north of Middle Fork Lake (of Boulder Creek) and flows in a north direction to join north and northeast oriented Middle Fork Bull Lake Creek downstream from Alpine Lake. North Fork Bull Lake Creek originates east of Fremont Peak and flows in a northeast, east, and southeast direction to join northeast oriented Bull Lake Creek as a barbed tributary. The unlabeled north-northeast oriented streams originating north of the North Fork Bull Lake Creek headwaters (east of the continental divide) are Dinwoody Creek and Dry Creek, both of which north of figure 2 flow in northeast directions to join the southeast oriented Wind River.West and south of the continental divide the Green River can be seen flowing in a north-northwest direction just west of continental divide (near north edge of figure 2) and then in a south-southwest direction across the northwest corner of figure 2. The Green River then flows in a south direction west of figure 2. The New Fork River originates near the northwest corner of figure 2 and flows in a southwest direction to and through New Fork Lakes before turning to flow in a south, south-southeast, and southeast direction to the south edge of figure 2. South of figure 2 the New Fork River turns to flow in a southwest direction to join the south oriented Green River. Marsh Creek is the southwest and south oriented stream joining the New Fork River west of New Fork Lakes. The Marsh Creek and Green River valleys are very close together near the northwest corner of figure 3 suggesting the Green River and New Fork River flow along the routes of what were once diverging flood flow channels. South of figure 2 the Green River and New Fork River valleys converge and almost meet before diverging again to flow around a region called “The Mesa” and finally converge with the New Fork River joining the Green River. This diverging and converging of valleys is typical in flood formed anastomosing channel complexes. New Fork River tributaries of interest in this essay begin with Pine Creek and then Fremont Creek, which originates near Fremont Peak and which flows in a south and southwest direction to join Pine Creek, which then flows to Fremont Lake and Pinedale before joining the southeast oriented New Fork River. Note how the north-northwest oriented Green River headwaters are located north of the south oriented Pine and Fremont Creek headwaters. Further east are south-southwest oriented Pole Creek and its south and southwest oriented Falls Creek tributary. South and east of Falls Creek is Boulder Creek, Which originates near Bald Peak and which flows in a southwest and west direction to Boulder Lake. West of Boulder Lake Boulder Creek turns to flow in a south direction to join the New Fork River near the south edge of figure 2 (near the town of Boulder). The Middle Fork of Boulder originates at Middle Fork Lake and flows in a south-southwest direction to join west oriented Boulder Creek.

South Fork Bull Lake Creek-Middle Fork Boulder Creek drainage divide area

Figure 3: South Fork Bull Lake Creek-Middle Fork Boulder Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of South Fork Bull Lake Creek-Middle Fork Boulder Creek drainage divide area. The map contour interval for figure 3 is 50 meters. The east-west continental divide follows the crest of the Wind River Range and is shown with a labeled dashed line extending from the northwest corner of figure 3 to the south center edge of figure 3. Mount Bonneville is located on the continental divide near the south center edge of figure 3. Moraine Lake is north of Mount Bonneville and on the east side of the continental divide. The North Fork Little Wind River originates at Moraine Lake and flows in a north, north-northeast, and east-northeast direction to the east edge of figure 3 (near northeast corner). East of figure 3 the North Fork Little Wind River flows to the southeast oriented Little Wind River, which then flows the northeast oriented Popo Agie River, which flows to the northeast and north oriented Wind-Bighorn River with water eventually reaching the Gulf of Mexico. The South Fork Bull Lake Creek originates on the north side of the continental divide near the center of figure 3 and flows in a north direction to the north edge of figure 3 (west of center). North of figure 3 the South Fork flows to northeast oriented Bull Lake Creek, which then flows to the southeast oriented Wind River. South of the South Fork Bull Lake Creek and on the south side of the continental divide is Middle Fork Lake. The Middle Fork Boulder Creek flows in a southwest direction from Middle Fork Lake to the south edge of figure 3 (west half). South of figure 3 the Middle Fork Boulder Creek joins west and south oriented Boulder Creek, which joins the southwest oriented New Fork River, which then flows to the south oriented Green River with water eventually reaching the Pacific Ocean. A north to south oriented trail crosses the pass or through valley linking the north oriented South Fork Bull Lake Creek valley with the south oriented valley draining to Middle Fork Lake. The pass or through valley floor elevation is between 3450 and 3500 meters. Elevations east of the pass rise to more than 3800 meters and west of the pass elevations rise to at least 3750 meters. These elevations suggest the pass or through valley is at least 250 meters deep. The pass or through valley is a water-eroded landscape feature and was eroded by south oriented flood flow moving on the present day north oriented South Fork Bull Lake Creek valley alignment to what were at that time actively eroding Boulder Creek tributary valleys. Floodwaters in the South Fork Bull Lake Creek valley were reversed when headward erosion of the much deeper northeast oriented Bull Lake Creek valley beheaded the south oriented flood flow channel. Crustal warping that was raising the Wind River Range as floodwaters flowed across it also contributed to the flood flow reversal. Another interesting through valley or pass is found linking the Middle Fork Lake basin with the Lake Kagevah basin to the northeast. Lake Kagevah drains to the north-northeast oriented North Fork Little Wind River valley. This second pass or through valley is used by a trail from the Middle Fork Boulder Creek valley to the North Fork Little Wind River valley and has a floor elevation of between 3400 and 3450 meters. Elevations north and south of this second pass rise to more than 3800 meters suggesting the pass is at least 350 meters deep. This second pass was eroded by southwest oriented flood flow moving from the present day north-northeast oriented North Fork Little Wind River valley to what were at that time actively eroding Boulder Creek tributary valleys. Floodwaters north and east of this second pass were reversed when headward erosion of the Little Wind River valley and its tributary North Fork Little Wind River valley beheaded and reversed the southwest oriented flood flow. Crustal warping as floodwaters flowed across the pass contributed to the flood flow reversal.

Detailed map of South Fork Bull Lake Creek-Middle Fork Boulder Creek drainage divide area

Figure 4: Detailed map of South Fork Bull Lake Creek-Middle Fork Boulder 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 South Fork Bull Lake Creek-Middle Fork Boulder Creek drainage divide area seen in less detail in figure 3. The map contour interval for figure 4 is 40 feet. The continental divide follows the crest of the Wind River Range and is shown with a labeled line extending from the northwest corner of figure 4 to the south edge of figure 4 (east half).  Photo Pass is located in section 29 near the center of figure 4 and links the north-northwest oriented South Fork Bull Lake Creek valley with the Bewmark Lake basin, which drains in a south direction to the Middle Fork Lake Basin. Middle Fork Lake drains in a southwest direction to Middle Fork Boulder Creek, which in turn drains to west-oriented Boulder Creek. The Photo Pass floor elevation is between 11,400 and 11,440 feet. The unnamed peak to the northeast rises to 12,548 feet and Halls Mountain to the northwest rises to 12,475 feet. These elevations suggest Photo Pass is at least 1000 feet deep. Valley glaciers sculpted landforms in figure 4 with numerous cirques, U-shaped valleys, hanging valleys, and other alpine glacial features. The glaciers formed in pre-existing valleys and modified those previously eroded valleys and probably did not erode new valleys. The north to south oriented Photo Pass through valley probably was modified by glacial action, however it probably was a pre-existing valley eroded by south oriented flood flow that crossed the Wind River Range long before the alpine glaciers existed. Kagevah Pass is located between Bewmark Lake and Lake Kagevah with Odyssey Peak to the north and Kegevah Peak to the south. Kagevah Lake today drains to the north-northeast oriented North Fork Little Wind River valley. Kagevah Pass has a floor elevation of between 11,280 and 11,320 feet. Odyssey Peak has an elevation 12,062 feet and Kagevah Peak has an elevation of 12,127 feet suggesting Kagevah Pass is at least 740 feet deep (proceeding further in both directions along the continental divide higher elevations than Odyssey Peak can be found so a case could be made that Kagevah Pass is even deeper). While the Kagevah Pass has definitely been altered by glacial erosion the pass probably originated as a water-eroded valley. If correctly interpreted the water was flowing in a southwest direction from the present day north-northeast oriented North Fork Little Wind River valley to the southwest oriented Middle Fork Boulder Creek valley. Headward erosion of the much deeper Bull Lake Creek and Little Wind River valleys beheaded and reversed south oriented flood flow channels as ice sheet related crustal warping raised the Wind River Range. Glaciation of the flood-eroded valleys occurred after all flood flow across the region had ended and after the Wind River Range had emerged as the high mountain range it is today.

Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area

Figure 5: Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area north and west of figure 3 and there is an overlap area with figure 3. The map contour interval for figure 5 is 50 meters. The east-west continental divide serves as the Fremont-Sublette County line and extends along the Wind River Range crest from the north edge of figure 5 (west of center) to near the southeast corner of figure 5. Hay Pass is located near the center of figure 5. Dennis Lake is north of Hay Pass and drains in a north and northeast direction as Middle Fork Bull Lake Creek to northeast oriented Bull Lake Creek, which flows to Alpine Lake seen along the north edge of figure 5 (east half). South Fork Bull Lake Creek originates near the southeast corner of figure 5 and flows in a north direction to the north edge of figure 5 (east of Alpine Lake) and joins Bull Lake Creek north of figure 5 to form northeast oriented Bull Lake Creek. Beth Lake is south of Hay Pass and south of Beth Lake is the northwest and south-southeast oriented North Fork Boulder Creek valley, which drains to Lake Victor near the south center edge of figure 5. Lake Victor drains in a southwest direction and North Fork Boulder Creek flows to west and south oriented Boulder Creek, which then flows to the southwest-oriented New Fork River. Hay Pass is a north to south oriented through valley crossing the continental divide and has a floor elevation of between 3300 and 3350 meters. The Hay Pass depth can be debated depending on how it is measured, however a case can be made that it is more than 300 meters deep. Hay Pass was probably eroded by south oriented flood flow moving to the what at that time was the actively eroding North Fork Boulder Creek valley. Headward erosion of the deeper northeast oriented Middle Fork Bull Lake Creek valley beheaded and reversed the flood flow channel to create the north oriented Middle Fork Bull Lake Creek headwaters drainage route. On the east side of Mount Victor a northwest to southeast oriented through valley links the northwest oriented North Fork Boulder Creek headwaters valley with a southeast and southwest oriented stream valley draining to Lake Victor. A southeast and southwest oriented flood flow channel probably diverged from and then converged with the south and south-southeast oriented North Fork Boulder Creek valley. These diverging and converging flood flow channels provide evidence of an anastomosing channel complex that once crossed the present day continental divide. Another set of diverging and converging former flood flow channels can be seen west of Round Top Mountain. Crustal warping that raised the Wind River Range as floodwaters flowed across it contributed to flood flow reversals and to the formation of the drainage divide (now the continental divide). Valley glaciers have modified these diverging and converging valleys, although the glaciers formed in pre-existing valleys and did not erode new valleys.

Detailed map of Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area

Figure 6: Detailed map of Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 6 provides a detailed map of the Middle Fork Bull Lake Creek-North Fork Canyon Creek drainage divide area seen in less detail in figure 5. The map contour interval for figure 6 is 40 feet. The east-west continental divide serves as the county line and is shown with a labeled line and extends from near the northwest corner of figure 6 to the south edge of figure 6 (east half). Hay Pass is located near the center of figure 6. Dennis Lake is north of Hay Pass and drains in a north direction to Golden Lake. The Middle Fork Bull Lake Creek flows in a south-southeast direction to Golden Lake and then turns to flow in a northeast direction to the north edge of figure 6 (east half). South of Hay Pass is an unnamed lake (Beth Lake in figure 5), which drains in a south direction to northwest and south oriented North Fork Boulder Creek. Hay Pass has a floor elevation of between 10,920 and 10,940 feet. To the southeast the continental divide rises to 11,615 feet and west of Hay Pass the continental divide rises to 11,719 feet (continuing further in either direction leads to even higher elevations). These elevations suggest Hay Pass is at least 750 feet deep. Alpine glaciers have significantly altered the region seen in figure 6 and there are cirques on both sides of Hay Pass. However, the north-to-south oriented through valley at Hay Pass was probably eroded before the glaciers formed. If correctly interpreted Hay Pass was eroded by south oriented flood flow moving to diverging flood flow channels on the present day northwest and south oriented North Fork Boulder Creek alignment. South-southwest oriented Fall Creek originates west of Round Top Mountain and flows through Timico Lake. South and west of figure 6 Fall Creek joins southwest oriented Pole Creek to flow to the southeast and southwest oriented New Fork River. North of the Fall Creek headwaters the continental divide is crossed by another north to south oriented pass or through valley. The floor of this second unnamed pass has an elevation of between 11,280 and 11,320 feet. Round Top Mountain rises to 12,048 feet and west of the pass the continental divide rises to 12,236 feet suggesting this second pass is approximately 700 feet deep. This second pass is also bounded by cirques on both sides, but also probably originated as south oriented flood flow channel (probably diverging from the flood flow channel flowing on the Hay Pass alignment). These diverging flood flow channels converged south of figure 6 on the New Fork River alignment. All flood flow across the region ended long before glaciers filled and modified the flood-eroded valleys. Wind River Range emergence as the high mountain range it is today occurred before the valley glaciers could be formed.

North Fork Bull Lake Creek-Fremont Creek drainage divide area

Figure 7: North Fork Bull Lake Creek-Fremont Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the North Fork Bull Lake Creek-Fremont Creek drainage divide area north and slightly west of figure 5 and includes an overlap area with figure 5. The map contour interval for figure 7 is 50 meters. The labeled east-west continental divide serves as the Fremont-Sublette County line and extends from the north edge of figure 7 (west half) to the south edge of figure 7 (slightly east of center). Mount Warren is located slightly east of the continental divide near the north edge of figure 7. The North Fork Bull Lake Creek originates near Mount Warren and flows in an east direction to Little Milky Lake where it turns to flow in a south direction to Big Milky Lake and then in a southeast direction to the east center edge of figure 7. Indian Pass is located near the center of figure 7 and Alpine Lakes are located south and east of Indian Pass. The Bull Lake Creek headwaters flow in an east-southeast direction from the southernmost of the Alpine Lakes to join northeast oriented Bull Lake Creek at the southwest end of Alpine Lake (near east edge of figure 7). Pole Creek originates west of the continental divide and south of Indian Pass and flows in southwest and south direction to Wall Lake and the south edge of figure 7 (slightly west of center). South of figure 7 Pole Creek joins the New Fork River, which eventually joins the south oriented Green River. Fremont Creek originates near Mount Warren on the west side of the continental divide and flows in a south direction to Island Lake and then in a west and south direction to the south edge of figure 7. South of figure 7 Fremont Creek joins Pine Creek, which flows to the New Fork River. The Green River (not labeled in figure 7) originates north of Bow Mountain (near northwest corner of figure 7) and flows in a north-northwest direction to the northwest corner of figure 7. North and west of figure 7 the Green River turns to flow in a south direction and eventually joins the Colorado River. Note how west of Bow Mountain a through valley (near Cube Rock Pass) links the north-northwest oriented Green River headwaters valley with the valley of a southeast oriented stream flowing to Island Lake (through Upper and Lower Jean Lakes). At Island Lake the southeast oriented stream joins west and south oriented Fremont Creek. The Green River-Fremont Creek through valley (Shannon Pass on more detailed maps) floor elevation is between 3400 and 3450 meters. Sky Pilot Peak to the west rises to 3697 meters and Bow Mountain to the east rises to 3968 meters. These elevations suggest Shannon Pass is at least 150 meters deep. South-southeast oriented floodwaters flowing parallel to and adjacent to the present day continental divide eroded Shannon Pass. Study of the region on both sides of the continental divide reveals many similar through valleys or passes describing what was probably an anastomosing complex of south oriented flood flow channels crossing the entire region (trails shown in figure 7 are located in several of the through valleys). As in previous figures the region seen in figure 7 was glaciated after flood flow had ended and after the Wind River Range had emerged as a high mountain range. As seen in figure 7 glaciers are still present and fill several valley heads. The glaciers formed in pre-existing valleys and glacial erosion did deepen and otherwise modify the valleys, but the glaciers probably did not carve new valleys.

Detailed map of Green River-Pine Creek drainage divide area

Figure 8: Detailed map of Green River-Pine 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 Green River-Pine Creek drainage divide partially seen in less detail in figure 7 above. The map contour interval for figure 8 is 40 feet. The east-west continental divide crosses the northeast corner of figure 8 and except for the northeast corner of figure 8 all regions in figure 8 drain to the Green River. Shannon Pass is located near the center of figure 8 and Cube Rock Pass is located a short distance north and west of Shannon Pass. Dale Lake is located on the west side of Cube Rock Pass and Peak Lake is on the east side. Dale Lake drains in a west direction to the north-northwest oriented Green River headwaters (“River” in figure 8), which flow to the north edge of figure 8. North of figure 8 the Green flows in a north-northwest and northwest direction before turning to flow in a south direction to eventually join the southwest oriented Colorado River. Peak Lake drains in a north direction to Stonehammer Lake. Stonehammer Lake drains in a west direction to the north-northwest oriented Green River and is also linked by a northwest oriented through valley with the north-northwest oriented Green River valley. Headwaters of a south-southeast oriented Fremont Creek tributary are located in section 34 south and east of Shannon Pass and flow to and through Upper Jean Lake before reaching the south edge of figure 8 (east half). South of Shannon Pass are also headwaters of Elbow Creek, which flows to Elbow Lake (near south edge of figure 8). At Elbow Lake Elbow Creek turns to flow in a northwest and west direction to join south oriented Pine Creek. Pine Creek originates at Green River Pass in section 30 (in west center area of figure 8) and south of figure 8 flows to the New Fork River, which in turn flows to the Green River. The north oriented stream flowing from Green River Pass to the north edge of figure 8 (west half) is Trail Creek, which north of figure 8 joins the northwest oriented Green River. The Green River Pass floor elevation is 10,362 feet. Mount Oeneis in section 29 rises to 12,232 feet. North and west of Green Pass (and not seen in figure 8) is Glover Peak, which rises to 12,068 feet. These elevations suggest Green River Pass could be as much as 1700 feet deep. Also in the northwest quadrant of figure 8 in section 20 Vista Pass links the Trail Creek valley with the Green River headwaters valley. Vista Pass has a floor elevation of between 10,120 and 10,160 feet. North of Vista Pass the high point is 10,945 feet and south of Vista Pass elevations rise to more than 12,200 feet suggesting Vista Pass is at least 750 feet deep. The through valleys or passes linking the north oriented Green River headwaters and tributary valleys with the south oriented New Fork River tributary valleys and also linking the various north to south oriented valleys with each other can be viewed in the context of what was once a south or south-southeast oriented anastomosing channel complex crossing the region. Headward erosion of the much deeper south oriented Green River valley west of figure 8 beheaded the south-southeast and south oriented diverging and converging flood flow channels. Floodwaters on the north and north-northwest ends of the beheaded flood flow channels reversed flow direction to create the north and north-northwest oriented Green River headwaters and tributary drainage routes. The flood flow reversal was probably aided by crustal warping that was raising the Wind River Range as floodwaters flowed across it.

Dinwoody Creek-North Fork Bull Lake Creek drainage divide area

Figure 9: Dinwoody Creek-North Fork Bull Lake Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the Dinwoody Creek-North Fork Bull Lake Creek drainage divide area north and east of figure 7 and there is an overlap area with figure 7. The map contour interval for figure 9 is 50 meters. The east-west continental divide extends in a south-southeast direction from the northwest corner of figure 9 to the south edge of figure 9 (west half). The north end of Dinwoody Glacier is located near the northwest corner of figure 9 and Klondike Lake is located east of the Dinwoody Glacier north end. Klondike Lake drains in an east direction to Dinwoody Creek, which flows from the south end of Dinwoody Glacier  (south of Gannett Peak) in a northeast direction to the north edge of figure 9 (west half). North of figure 9 Dinwoody Creek flows in a north, east, and northeast direction to join the southeast oriented Wind River. The North Fork Bull Lake Creek flows in an east direction from Mount Warren (south of Dinwoody Glacier) to Little Milky Lake and then turns to flow in a south and southeast direction through Big Milky Lake to the south edge of figure 9 (near southeast corner). South of figure 9 the North Fork joins Bull Lake Creek, which flows to the southeast oriented Wind River. West of the continental divide the south oriented stream flowing through the Titcomb Lakes is the headwaters of Fremont Creek, which flows to the New Fork River. There are two Indian Passes seen in figure 9. The first Indian Pass is located on the continental divide near the south edge of figure 9 and links a northeast oriented North Fork Bull Lake Creek tributary valley with the south oriented Fremont Creek valley. A trail crosses the continental divide using this first Indian Pass, which has an elevation of between 3650 and 3700 meters. Jackson Peak to the north rises to more than 4050 meters and Harrower Peak to the south (but not on the continental divide) rises to 3978 meters. These elevations suggest the first Indian Pass is approximately 300 meters deep. The second Indian Pass is located at the west end of Dry Creek Ridge (near center of figure 9) and links the north-northeast oriented Dry Creek headwaters valley with east oriented North Bull Lake Creek valley and also with northeast oriented North Bull Lake Creek tributary valley originating at the first Indian Pass. The second Indian Pass floor elevation is between 3500 and 3550 meters. Dry Creek Ridge to the east rises to more than 3850 meters and Mount Febbas to the west rises to more than 4050 meters. These elevations suggest the second Indian Pass is at least 300 meters deep. These two Indian Passes are located on what was once a south-southwest oriented flood flow channel moving floodwaters to the south oriented Fremont Creek valley. Floodwaters were first beheaded by headward erosion of the east oriented North Fork Bull Lake Creek valley, which eroded headward from the actively eroding southeast oriented Wind River valley. The flood flow channel was again beheaded north of figure 9 by headward erosion of the north-northeast oriented Dry Creek valley, which eroded headward from the actively eroding southeast oriented Wind River valley. The sequence of captures is consistent with headward erosion of the deep southeast oriented Wind River valley. Greatly aiding in headward erosion of the southeast oriented Wind River valley was crustal warping that was raising the Wind River Range as floodwaters flowed across it.

Detailed map Dry Creek-North Fork Bull Lake Creek drainage divide area

Figure 10: Detailed map of Dry Creek-North Fork Bull Lake 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 Dry Creek-North Fork Bull Lake Creek drainage divide area seen in less detail in figure 9. The map contour interval for figure 10 is 40 feet. The east-west continental divide is located west of figure 10. Indian Pass (the second Indian Pass described in figure 9) is located near the center of figure 10 between Dry Creek Ridge to the east and Horse Ridge to the west. The lakes north of Indian Pass drain to north-northeast direction and northeast oriented Dry Creek, which flows to the southeast oriented Wind River. The North Fork Bull Lake Creek originates at Helen Glacier (not labeled in figure 10), which straddles the west edge of figure 10 (south half), and then flows in an east and east-southeast direction to the east edge of figure 10. East of figure 10 the North Fork flows to Bull Lake Creek, which then flows to the southeast oriented Wind River. The northeast oriented tributary joining the North Fork Bull Lake Creek south of Indian Pass is flowing in a northeast oriented valley, which south of figure 10 is linked to the southwest by the first Indian Pass discussed in figure 9 and then to southwest oriented valleys draining to Fremont Creek and the New Fork River. The Indian Pass in section 23 in figure 10 has a floor elevation of between 11,460 and 11,480 feet. Dry Creek Ridge to the east rises to more than 12,720 feet and Mount Febbas to the west rises to 13,468 feet suggesting Indian Pass is approximately 1000 feet deep. Indian Pass was eroded by south-southwest oriented flood flow flowing on the present day north-northeast oriented Dry Creek headwaters alignment and on the alignment of the present day northeast oriented North Fork Bull Lake Creek tributary valley to what at that time was the actively eroding south oriented Fremont Creek valley south and west of the present day continental divide. Headward erosion of the Bull Lake Creek valley captured the flood flow and diverted floodwaters to the newly eroded southeast oriented Wind River valley. The North Fork Bull Creek valley also captured southeast oriented flood flow from west of the figure 10, which was flowing through Blaurock Pass (near west edge of figure 10 and Mount Febbas) and through Backpackers Pass (west of figure 10). Those captured floodwaters were flowing across the present day northeast oriented Dinwoody Creek headwaters valley area. Floodwaters on the northeast end of the beheaded southwest oriented flood flow route reversed flow direction to create the northeast oriented North Fork Bull Lake Creek tributary drainage route. Subsequently headward erosion of the northeast oriented Dry Creek valley from the actively eroding southeast oriented Wind River valley beheaded and reversed the south-southwest oriented flood flow moving across Indian Pass to the newly eroded North Fork Bull Lake Creek valley. The capture of flood flow flowing to the North Fork Bull Lake Creek valley west of figure 10 by headward erosion of the Dinwoody Creek valley occurred still later. After all flood flow across the region had ended and after the Wind River Range had emerged as a high mountain range valley glaciers filled many of the valleys seen in figure 10. And the glaciers may have covered the entire landscape seen in figure 10. The glaciers deepened, widened, and streamlined some of the valleys and probably sculpted the regional bedrock surface, but probably did not erode narrow valleys. In other words the valley orientations seen in figure 10 probably still reflect the previously eroded flood flow channel routes.

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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