Abstract:

This essay uses topographic map evidence to interpret landform origins in the region between Little Popo Agie River and Beaver Creek at the Wind River Range southeast end, Fremont County, Wyoming. Beaver Creek and the Little Popo Agie River both originate at the southeast end of the Wind River and flow in different directions to eventually join the northeast oriented Popo Agie River in the Wind River Basin to the northeast. The Little Popo Agie River flows in a northeast direction from the Wind River Range into the Wind River Basin and then flows in a northeast and north direction to join the northeast oriented Popo Agie River. Beaver Creek flows in an east-southeast and east direction to the Wind River Basin south end and then turns to flow in a north and north-northwest direction to join the Popo Agie River. The Popo Agie River then flows to the northeast and north oriented Wind River, which becomes the north-oriented Bighorn River and which flows to the northeast oriented Yellowstone River. Through valleys cross the Little Popo River-Beaver Creek drainage divide and drainage divides between their tributaries at all elevations from the Little Popo Aige River and Beaver Creek headwaters in the high Wind River Range to the area near the Popo Agie River where the Little Popo Agie River and Beaver Creek valleys converge. In addition to the through valleys barbed tributaries, elbows of capture, water gaps, and wind gaps are common landform features. The topographic map evidence is interpreted in the context of immense floods, which crossed the region. Floodwaters were flowing from western Canada from the western margin of a thick North American ice sheet. Mountains ranges, including the Wind River Range, emerged as floodwaters deeply eroded surrounding regions and as ice sheet related crustal warping raised the mountain ranges relative to adjacent areas. A massive flood flow reversal in the present day Wind River Basin region occurred when headward erosion of the deep northeast oriented Yellowstone River valley from space at the south end of the deep “hole” the melting ice sheet had occupied beheaded flood flow routes to Wyoming in sequence from east to west. Floodwaters on north ends of beheaded flood flow routes reversed flow direction to create north oriented drainage routes such as the north oriented Wind River and Bighorn River drainage routes. Northeast, east, and southeast oriented valley eroded headward from these newly formed north oriented drainage routes to capture floodwaters still moving in a south direction further to the west. Topographic map evidence demonstrates headward erosion of the northeast oriented Popo Agie River valley beheaded and reversed flood flow on the Beaver Creek alignment first with the reversed flood flow capturing flood flow still moving in a south direction on the alignments of present day north oriented Little Popo Agie River tributaries. Topographic map evidence also demonstrates headward erosion of the northeast oriented Little Popo Agie River valley in the present day Wind River Range beheaded southeast oriented flood flow channels to the Beaver Creek headwaters valley. Further, map evidence demonstrates, large volumes of north oriented flood flow that must have crossed the southeastern Wind River Range before being captured by the Beaver Creek valley, deeply eroded the southern Wind River Basin.

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 Little Popo Agie River-Beaver Creek drainage divide area landform origins at the Wind River Range southeast end, Fremont County, 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 Little Popo Agie River-Beaver Creek drainage divide area landform evidence at the Wind River southeast end will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Little Popo Agie River-Beaver Creek drainage divide area location map

Figure 1: Little Popo Agie River-Beaver Creek drainage divide area location map (select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

Figure 1 provides a location map for the Little Popo Agie River-Beaver Creek drainage divide area at the Wind River Range southeast end and illustrates a region in west-central Wyoming. Togwotee Pass is located near the northwest corner of figure 1. The Wind River originates near Togwotee Pass and flows in a southeast direction between the Wind River Range and the Owl Creek Mountains to Riverton in the Wind River Basin and then turns in a northeast and north direction to flow to Boysen Reservoir. From Boysen Reservoir the Wind River flows in a north direction through deep Wind River Canyon, which has been eroded across the Owl Creek Mountains eastern end. North of Wind River Canyon and near Thermopolis the Wind River enters the Bighorn Basin and the river name changes to become the Bighorn River. The Bighorn River flows in a north direction through the Bighorn Basin and north of figure 1 in Montana the Bighorn River eventually joins the northeast oriented Yellowstone River with water ultimately reaching the Gulf of Mexico. The Popo Agie River  (shown, but labeled in figure 1) is a northeast oriented Wind River tributary originating in the Wind River Range and flowing to the towns of Lander, Hudson, and Arapahoe before reaching Riverton and the Wind River. The Little Popo Agie River is the Popo Agie River tributary originating north of Granite Peak and joining the Popo Agie River near the town of Hudson. Beaver Creek (also shown, but not labeled in figure 1) originates east of Granite Peak and north of Atlantic City and flows in an east-southeast direction before turning to flow in a north and north-northwest direction to join the Popo Agie River between the towns of Arapahoe and Riverton. South oriented drainage routes near the southwest corner of figure 1 flow to the south oriented Green River, which then flows to the southwest oriented Colorado River and Pacific Ocean. The Little Popo Agie River-Beaver Creek drainage divide area investigated in this essay is located south and east of the Little Popo Agie River and north and west of Beaver Creek and includes areas in the Wind River Range as well as areas in the Wind River Basin.

The Little Popo Agie and Beaver Creek drainage routes along with all other drainage routes seen in figure 1 evolved during immense floods, which at one time flowed in south directions across the entire region seen in figure 1. The floodwaters were flowing from the western margin of a thick North American ice sheet and flowed from western Canada to and across Wyoming. At first Montana, Wyoming, Colorado, and many other mountain ranges had not emerged and floodwaters were able to freely flow across what are today major mountain barriers. The mountain ranges emerged as floodwaters deeply eroded surrounding regions and as ice sheet related crustal warping raised the mountain ranges relative to the adjacent areas. Ice sheet related crustal warping combined deep glacial erosion also created a deep “hole” in which the huge ice sheet was located. The present day north oriented Beaver Creek alignment originated as a south oriented flood flow channel, which probably derived its flood water from south oriented flood flow on the present day north oriented Wind River Canyon alignment.  South oriented flood flow on the present day north oriented Beaver Creek alignment at one time flowed between the emerging Wind River Range and the emerging Granite and Green Mountains with the floodwaters eventually reaching the actively eroding Colorado River valley. At that time the Wind River Basin had not been eroded and there was no deep southeast oriented Wind River valley between the Wind River Range and the Owl Creek Mountains. Instead south oriented flood flow channels crossed the emerging Wind River Range to reach the actively eroding Green River headwaters and tributary valleys seen along the Wind River Range southwest flank.

The present day north oriented Bighorn and Wind River drainage system evolved during a massive flood reversal triggered by headward erosion of the deep northeast oriented Yellowstone River valley across Montana (to the north of figure 1). The deep northeast oriented Yellowstone River valley eroded headward from space at the south end of the deep “hole” the melting ice sheet had occupied and which at first was being drained in a south direction across eastern Nebraska. Headward erosion of the deep Yellowstone River valley beheaded the south oriented flood flow routes crossing Wyoming in sequence from east to west. Floodwaters on north ends of the beheaded flood flow channels reversed flow direction to flow in a north direction to the much deeper northeast oriented Yellowstone River valley. Because flood flow channels were beheaded and reversed one at a time and from east to west the newly reversed flood flow channels were able to capture flood flow from yet to be beheaded flood flow channels further to the west. When headward erosion of the deep northeast oriented Yellowstone River valley beheaded a south oriented flood flow channel delivering floodwaters to the south oriented flood flow channel on the Wind River Canyon alignment there was a major reversal of flood flow that created the north oriented Bighorn River and Wind River drainage routes. Subsequently headward erosion of the northeast oriented Popo Agie River valley from that newly reversed flood flow route beheaded and reversed south oriented flood flow on the present day north oriented Beaver Creek alignment and created the north oriented Beaver Creek drainage route. The east-southeast oriented Beaver Creek headwaters valley then eroded headward from this reversed flood flow route to capture south and southeast oriented flood flow west of the reversed flood flow channel. Apparently the reversed flood flow on the north oriented Beaver Creek alignment was able to capture large volumes of flood flow moving across the emerging Wind River Range southeast end because the north oriented flood flow eroded much of the southern Wind River Basin. In time headward erosion of northeast oriented Popo Agie River valley beheaded and reversed south oriented flood flow on the present day north oriented Little Popo Agie River alignment to create the north oriented Little Popo Agie River drainage segment. The northeast oriented Little Popo Agie River headwaters valley next eroded headward from the newly formed north oriented Little Popo Agie River drainage route to behead south and southeast oriented flood flow routes to the newly eroded east-southeast oriented Beaver Creek headwaters valley. Headward erosion of the deep southeast oriented Wind River valley eventually beheaded all flood flow routes crossing the emerging Wind River and contributed significantly to the emergence of the Wind River Range and the Owl Creek Mountains. Many details have been omitted from this brief description, some of which are provided in the following discussions and many of which are left for future researchers to determine.

Detailed location map for Little Popo Agie River-Beaver Creek drainage divide area

Figure 2: Detailed location map Little Popo Agie River-Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 2 provides a detailed location map for the Little Popo Agie River-Beaver Creek drainage divide area at the Wind River Range southeast end. The green colored area is National Forest land in the Wind River Range. The Sweetwater River flows in a southeast direction across the southwest corner of figure 2 and south of figure 2 turns to flow in an east-northeast to Sweetwater Station and the east edge of figure 2. East  Sweetwater River originates in the Wind River Range (north and west of South Pass City) and flows in a southwest, south, and southwest direction to join the southeast oriented Sweetwater River near the southwest corner of figure 2. East of figure 2 the Sweetwater River flows in an east direction to reach the north, northeast, east, and southeast North Platte River. Crooks Mountain is located in the southeast corner of figure 2. Beaver Creek originates west and north of the town Miners Delight and flows in an east-southeast and east direction towards the Sweetwater River, but then makes an abrupt turn to flow in a north direction to the north edge of figure 2 (east half). North of figure 2 Beaver Creek joins the Popo Agie River with water then flowing to the north oriented Wind River and Bighorn River. The drainage divide between the Beaver Creek drainage basin east of the north oriented Beaver Creek segment and the Sweetwater River drainage basin is a northwest-facing escarpment known as Beaver Divide and marks the boundary between the deeper Wind River Basin to the north and west and the higher elevation Sweetwater River drainage basin to the south and west. The Middle Popo Agie River originates west of figure 2 and flows in an east and northeast direction from the west edge of figure 2 to Lander and the north edge of figure 2 (west half). The Little Popo Agie River originates north of the East Sweetwater River headwaters and west of the Beaver Creek headwaters and flows in a northeast direction almost to Blue Ridge before turning to flow in a north-northwest and north-northeast direction to the north center edge of figure 2 and north of figure 2 joins the northeast oriented Popo Agie River, which then flows to the northeast and north oriented Wind River. Twin Creek is a labeled east, north, west, and northwest oriented Little Popo Agie Creek tributary originating north of the Beaver Creek headwaters (north of Miners Delight) and flowing first towards Sheep Mountain, then turning to flow towards Blue Ridge, before turning to join the Little Popo Agie River. As the detailed maps below illustrate several drainage routes seen in figure 2 originate on the southwest side of the present day Wind River Range crest and first flow in southeast and/or east directions before turning to turn in north directions once east of the Wind River Range. These drainage routes were established as the Wind River Range was emerging and they captured significant south oriented flood moving west of the beheaded and reversed flood flow route on the present day north oriented Beaver Creek alignment. Headward erosion of the east-northeast Sweetwater River valley segment probably captured significant flood flow that had been flowing into the Wind River Basin including significant southeast oriented flood flow moving along the Wind River Range southwest flank.

Pass Creek-Beaver Creek drainage divide area

Figure 3: Pass Creek-Beaver Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of Pass Creek-Beaver Creek drainage divide area. The map contour interval for figure 3 is 50 meters. The region seen in figure 3 is located near the southeastern end of the high Wind River Range. Granite Peak near the southwest corner of figure 3 reaches an elevation of 31717 meters and is the highest point seen in figure 3. Elevations in the Red Canyon Creek valley near the northeast corner of figure 3 are approximately 1800 meters. The Little Popo Agie River flows in an east-northeast direction from the west center edge of figure 3 to Little Popo Agie Canyon and then to the north edge of figure 3 (east half). Limestone Mountain is located near the center of figure 3. Pass Creek flows in a northeast direction just west of Limestone Mountain and as Pass Creek approaches Young Mountain the stream turns to flow in a northwest direction to join the northeast oriented Little Popo Agie River. Cherry Creek originates east of Limestone Mountain and flows in a north and northeast direction to join Red Canyon Creek near the north edge of figure 3 with Red Canyon Creek then flowing to join the Little Popo Agie River. Note how a deep through valley links the Pass Creek valley with the Cherry Creek valley. The through valley floor elevation is between 2300 and 2350 meters. Young Mountain to the north rises to 2678 meters and Limestone Mountain to the south rises to more than 2750 meters. These elevations suggest the through valley is at least 300 meters deep. While the through valley may be related to the regional geologic structures the through valley is also a water-eroded feature. Study of figure 3 reveals the through valley can be traced headward in a northwest direction between Bayer Mountain and Freak Mountain suggesting it was once the route of a southeast oriented flood flow channel. Headward erosion of the deeper northeast oriented Little Popo Agie River valley captured the southeast oriented flood flow. Floodwaters on the northwest end of the beheaded flood flow route reversed flow direction to create the northwest oriented Pass Creek drainage segment. The northeast oriented Pass Creek valley then eroded headward from the reversed flood flow route to capture floodwaters still moving in a southeast direction west of the actively eroding Little Popo Agie River valley head. Those floodwaters had been moving to the actively eroding Beaver Creek valley. Iron Mountain is south of Limestone Mountain. Beaver Creek originates south of the Pass Creek headwaters and flows in an east direction between Limestone Mountain and Iron Mountain before turning to flow in a southeast direction to the southeast corner of figure 3. West of Limestone Mountain a southeast oriented through valley links the northeast oriented Pass Creek headwaters valley with east and southeast oriented Beaver Creek valley. Figure 4 provides a detailed map of the Pass Creek-Beaver Creek drainage divide area to better illustrate the regional through valleys.

Detailed map of Pass Creek-Beaver Creek drainage divide area

Figure 4: Detailed map of Pass Creek-Beaver 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 Pass Creek-Beaver Creek drainage divide area seen in less detail in figure 3. The map contour interval for figure 4 is 20 feet. Beaver Creek originates in the southwest quadrant of figure 4 (near the corner of sections 15, 16, 21, and 22) and flows in a southeast, northeast, southeast, and east direction to near the southeast corner of figure 4. Pass Creek originates in section 9 north of the Beaver Creek headwaters and flows in a northeast direction to the north edge of figure 4 (slightly west of center). Limestone Mountain is labeled and is located just east of the highway extending in a south direction from the north center edge of figure 4. In section 11 the highway crosses the Pass Creek-Beaver Creek drainage divide using a through valley or pass at an elevation of between 8760 and 8780 feet. The through valley links a north oriented valley leading to the Pass Creek valley near the north edge of figure 4, which has an elevation of less than 7900 feet, and a southeast oriented Beaver Creek tributary valley. Beaver Creek near the southeast corner of figure 4 has an elevation of less than 7900 feet. Elevations on Limestone Mountain in section 11 directly east of the through valley rise to 9102 feet and is more than 300 higher than the through valley floor. While topography west of the through valley is more rugged elevations west of the Pass Creek and Beaver Creek headwaters are higher than the top of Limestone Mountain. A close look at the Pass Creek-Beaver Creek drainage divide area reveals evidence that the region was eroded by southeast oriented flood flow. A low northwest to southeast oriented northeast-facing escarpment extends from the west edge of figure 4 (south of center) across the southwest quadrant of section 16 and then to south edge of figure 4. This low escarpment is probably what remains of the southwest wall of a southeast oriented flood flow channel that was bounded on the northeast by Limestone Mountain (which is a large hogback ridge). The southeast oriented Beaver Creek tributary in section 15 is linked by a shallow through valley with the northeast oriented Pass Creek valley. While the high Wind River Range seems today to be an unlikely place to look for evidence of massive southeast oriented floods being captured by headward erosion of deep east and northeast oriented valleys the evidence is present and can be seen by anyone who will take the time to look.

Twin Creek-Beaver Creek drainage divide area

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

Figure 5 illustrates the Twin Creek-Beaver Creek drainage divide area east of figure 3 and there is an overlap area with figure 3. The map contour interval for figure 5 is 50 meters. Red Canyon Creek is the north oriented stream flowing to the northwest corner of figure 5. Beaver Creek flows in a southeast direction across the southwest corner of figure 5 and then turns to flow in an east direction near the south edge of figure 5 before turning near the southeast corner of figure 5 to flow in a north and west direction around Schoettlin Mountain and then to flow in a north-northeast direction to the east edge of figure 5 (north half). Beaver Creek crosses the 1750-meter contour line near the east edge of figure 5. Twin Creek flows in an east and northeast direction from the west center edge of figure 5 (near highway) toward Sheep Mountain and the turns to flow in a north direction along the Sheep Mountain west flank to the north center edge of figure 5. North of figure 5 Twin Creek turns to flow in a west and north-northwest direction to eventually join the Little Popo Agie River. Note how a through valley between Sheep Mountain and Schoettlin Mountain links the north oriented Twin Creek valley with the north-northeast oriented Beaver Creek valley. Also east of Sheep Mountain a through valley links the north and west oriented Red Bluff Creek valley with the southeast oriented Red Canyon valley. Orientations of these through valleys are controlled to some extent by the regional geologic structures, but the through valleys are also water-eroded valleys and were eroded by south oriented flood flow on the present day north oriented Twin Creek alignment moving to north-northeast flood flow on the Beaver Creek alignment. Remember flood flow routes were beheaded and reversed in sequence generally from east to west. In this case south oriented flood flow routes were probably being beheaded and reversed by headward erosion of the northeast oriented Popo Agie River valley. South oriented flood flow on the Twin Creek alignment was captured by the headward erosion of the deeper north-northeast oriented Beaver Creek valley and made a U-turn around the south end of Sheep Mountain to erode the east oriented valley between Sheep Mountain and Schoettlin Mountain. Headward erosion of the deep northeast oriented Popo Agie River valley north of figure 5 next beheaded and reversed the flood flow on the Twin Creek alignment to create the north oriented Twin Creek drainage route. [Twin Creek make significant direction changes north of figure 5 that suggest the Twin Creek flood flow reversal probably occurred in several stages, even though my description implies the reversal occurred in a single stage.]

Detailed map of Twin Creek-Beaver Creek drainage divide area

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

Figure 6 provides a detailed topographic map of the Twin Creek-Beaver Creek drainage divide area seen in less detail in figure 5. The map contour interval for figure 6 is 20 feet. Twin Creek flows in an east-northeast direction from the west edge of figure 6 (north of center) to the Bergstedt Ranch in section 1 and then turns to flow in north direction to the north edge of figure 6 (near northwest corner). Wilson Draw is a northeast and north-northwest oriented tributary joining Twin Creek near the Bergstedt Ranch and is joined in section 7 by a northwest oriented tributary flowing from near the Mathisen Ranch. Sheep Mountain is located east of the Bergstedt Ranch and has a high point of 7442 feet. The Bergstedt Ranch house elevation is between 6140 and 6160 feet. Schoettlin Mountain is located south of the southeast corner of figure 6. Beaver Creek flows in an east, north, and west direction around Schoettlin Mountain and then turns to flow in a north direction into figure 6 near Rocky Ford (near south edge of figure 6-east half). North of Rocky Ford Beaver Creek turns to flow in a north-northeast direction to the east edge of figure 6 (north of center). The east oriented stream flowing from the Miller Spring area near the south center edge of figure 6 is a Beaver Creek tributary and has eroded a water gap near the corner southeast corner of section 16 and the southwest corner of section 16. The water gap floor elevation is between 6400 and 6420 feet. While not seen in figure 6 Schoettlin Mountain to the south of figure 6 rises to 7123 feet. South of figure 6 there is a west to east oriented wind gap also linking the Miller Spring basin with the Beaver Creek valley. The Schoettlin Mountain elevation and the Sheep Mountain elevation and the water and wind gap between them suggest there is a 700-foot deep valley between Sheep Mountain and Schoettlin Mountain that was eroded by at least two different east oriented channels. The water that eroded this major east oriented valley, including the present day water gap and wind gap, flowed in a south direction from the present day north oriented Twin Creek alignment. A through valley in section 17 links the north-northwest oriented Twin Creek tributary valley with the Miller Spring drainage basin. Red Bluff Canyon extends from section 32 near the north edge of figure 6 in a southeast and east-southeast direction to join Beaver Creek in section 11 (near east edge of figure 6). The road in section 32 crosses the drainage divide to enter the valley of north and west oriented Red Buff Creek, which joins Twin Creek north of Sheep Mountain. The floor elevation of the through valley in section 32 is between 6540 and 6560 feet. Elevations in section 32 east of the through valley rise to more than 6800 feet suggesting the through valley is at least 240 feet deep. This through valley was also eroded by south oriented flood flow diverging from the south oriented flood flow channel on the present day north oriented Twin Creek alignment. The south oriented flood flow on these two diverging south oriented flood flow routes was captured by headward erosion of the north-northeast oriented Beaver Creek valley, which was eroding headward from the north and north-northwest oriented Beaver Creek drainage route north and east of figure 6. The north and north-northwest oriented Beaver Creek drainage route had been beheaded and reversed by headward erosion of the deep northeast oriented Popo Agie River valley north of figure 6. Headward erosion of the Popo Agie River valley subsequently beheaded and reversed flood flow on the Twin Creek alignment and ended flood flow across the through valleys seen in section 32 and in section 17.

Dry Twin Creek-Hall Creek drainage divide area

Figure 7: Dry Twin Creek-Hall Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 7 illustrates the Dry Twin Creek-Hall Creek drainage divide area north and slightly east of figure 5 and includes an overlap area with figure 5. The map contour interval for figure 7 is 50 meters. Beaver Creek flows in a north direction near the east edge of figure 7. Hall Creek is an east, north, and east oriented Beaver Creek tributary in the southeast quadrant of figure 7. Cedar Draw is an east-southeast and northeast oriented Hall Creek tributary. Del Monte Draw in an east and northeast oriented Beaver Creek tributary located north of Cedar Draw. Twin Creek flows in a north direction from the south edge of figure 7 (west of center) to near the highway and then makes an abrupt turn to flow in west direction past the Derby Dome Oilfield and then turns to flow in a north-northwest direction to the west center edge of figure 7. Red Bluff Creek flows in a north and west direction to join Twin Creek near the south edge of figure 7. Sheep Mountain is located south of figure 7 between the north oriented Twin Creek and Red Bluff Creek valleys (see figure 5). Dry Twin Creek originates just north of the south center edge of figure 7 and flows in a north and northwest direction to join Twin Creek at the point where Twin Creek turns from flowing in a north direction to flowing in a west direction. Figure 7 is not the easiest topographic map to be read as the 50-meter contour interval omits many topographic details and only the 250-meter contour lines are dark enough to easily see. However, the through valleys cross present day drainage divides and are evidence of former flood flow routes. One of the deeper through valleys links the northwest oriented Dry Twin Creek valley with the east oriented Hall Creek valley and is illustrated in more detail in figure 8. Another through valley links the west oriented Twin Creek valley with the east oriented Del Monte Draw headwaters valley. These through valleys provide evidence of east oriented flood flow on the present day west oriented Twin Creek alignment that was probably moving to the newly reversed flood flow on the north oriented Beaver Creek alignment. If correctly interpreted the flood flow was moving in a south direction on the present day north-northwest oriented Twin Creek alignment and then flowing in west direction to the north oriented Beaver Creek valley so as to make a giant U-turn in the region seen in figure 7. This U-turn is consistent with the headward erosion of the deep northeast oriented Popo Agie River valley north of figure 7, which beheaded and reversed south oriented flood flow channels flowing across the region seen in figure 7 in sequence from east to west. Flood flow on the Beaver Creek alignment would have been beheaded and reversed first and would have been able to capture flood flow still moving in a south direction on the Twin Creek alignment. Subsequently flood flow on the Twin Creek alignment was beheaded and reversed, which created the Twin Creek-Beaver Creek drainage divide.

Detailed map of Dry Twin Creek-Hall Creek drainage divide area

Figure 8: Detailed map of Dry Twin Creek-Hall 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 Dry Twin Creek-Hall Creek drainage divide seen in less detail in figure 7 above. The map contour interval for figure 8 is 20 feet. Beaver Creek flows in a north direction across the southeast corner of figure 8. Dry Twin Creek originates in section 20 (near southwest corner of figure 8) and flows in a north and northwest direction to the northwest corner of figure 8. The North Fork Hall Creek originates near the southwest corner of section 28 and flows into the northeast quadrant of section 22 where it turns to flow in an east direction to join the northeast oriented South Fork Hall Creek near the east edge of section 23 and to form Hall Creek. Hall Creek then flows in a north-northeast direction from the northwest corner of section 24 to the southwest corner of section 6 where it turns to flow in an east direction to the east edge of figure 8 (near northeast corner). A through valley in the southwest quadrant of section 16 links the north-northwest oriented Dry Twin Creek valley with an east-southeast oriented North Fork Hall Creek tributary valley. The through valley is approximately 100 feet deep and is located between hogback ridges and is definitely oriented along the geologic structure, however the through valley is also a water-eroded valley and was eroded by southeast oriented flood flow moving from the present day north-northwest oriented Dry Twin Creek alignment to the east, north, and east oriented Hall Creek alignment. An interesting drainage history is told by drainage routes and through valleys seen in the southeast quadrant of figure 8. A through valley in southwest quadrant of section 24 links a north oriented Hall Creek tributary valley with an east oriented Beaver Creek tributary valley. The 240-foot deep through valley was eroded by southeast and east oriented flood flow moving to the Beaver Creek valley prior to headward erosion of the deep north-northeast oriented Hall Creek valley.  This set of valleys is difficult to explain unless for a time floodwaters were flowing simultaneously in an east direction directly to Beaver Creek and also in a north direction on the north-northeast oriented Hall Creek alignment. Probably at the time floodwaters were reversed to flow in a north direction on the Beaver Creek alignment a deep north oriented knick point eroded headward in the Beaver Creek valley and also along the newly formed east and north oriented Hall Creek valley. The deep knick point probably was not able to erode headward on the east oriented Beaver Creek tributary valley in sections 24 and 19 before the deep knick point eroded headward on the Hall Creek valley in section 24. The result was the deeper Hall Creek valley captured all of the southeast and east oriented flood flow to the east oriented Beaver Creek tributary valley, which ended flood flow across the section 24 through valley.

Government Draw-Ninemile Draw drainage divide area

Figure 9: Government Draw-Ninemile Draw drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the Government Draw-Ninemile Draw drainage divide area north of figure 7 and there is an overlap area with figure 7. The map contour interval for figure 9 is 50 meters. The Popo Agie River flows in a northeast direction across the northwest corner of figure 9. The Little Popo Agie River flows in a north-northeast direction from the west center edge of figure 9 to the north edge of figure 9 (near the town of Hudson) and joins the Popo Agie River north of figure 9. Government Draw drains in a north-northwest direction from the south edge of figure 9 (west half) to join the Little Popo Agie River. The North Fork Ballenger Draw originates slightly south of the center of figure 9 and flows in a southwest direction to join the southwest and west oriented South Fork (which originates near Cottontail Reservoir) to form southwest oriented Ballenger Draw, which drains to Government Draw as a barbed tributary. South of Ballenger Draw is southwest oriented Fivemile Draw, which also drains to north-northwest oriented Government Draw as a barbed tributary. North of Ballenger Draw is west-southwest and northwest oriented Monument Draw, which also drains to Government Draw. Beaver Creek flows in a northwest and northeast direction just north of the southeast corner of figure 9 and then in a north-northwest direction across the northeast corner of figure 9. North of figure 9 Beaver Creek joins the northeast oriented Popo Agie River. Ninemile Draw drains in a northeast direction from the south edge of figure 9 (east half) to join Beaver Creek just east of the north edge of figure 9 (north of center). The region seen in figure 9 is on the Wind River Basin floor where relief is low and most topographic features do not show up with a 50-meter contour interval. Figure 10 provides a more detailed topographic map of the South Fork Ballenger Draw-Ninemile Draw drainage divide area. The southwest oriented Government Draw tributaries provide evidence the Government Draw drainage route oriented as a southeast oriented flood flow channel with diverging south oriented flood flow channels on alignments of present day north oriented Government Draw tributaries (e.g. Carr Springs Draw near southwest corner of figure 9). South oriented flood flow on the Government Draw alignment was beheaded and reversed by headward erosion of what was at that time a much deeper north-northeast valley on the Little Popo Agie River alignment (which may have eroding headward along a south oriented flood flow channel beheaded and reversed by headward erosion of the northeast oriented Popo Agie River valley). As described previously headward erosion of the northeast oriented Popo Agie River valley beheaded the south oriented flood flow channels in sequence from east to west. South oriented flood flow on the Beaver Creek alignment was beheaded and reversed before south oriented flood flow on the Government Draw alignment was beheaded and reversed and reversed flood flow on the Beaver Creek alignment was able to capture south oriented flood flow from the Government Draw alignment.

Detailed map South Fork Ballenger Draw-Ninemile Draw drainage divide area

Figure 10: Detailed map of South Fork Ballenger Draw-Ninemile Draw 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 South Fork Ballenger Draw-Ninemile Draw drainage divide area seen in less detail in figure 9. The map contour interval for figure 10 is 20 feet. Ninemile Draw drains in a north-northeast direction from the south edge of figure 10 (east half) to the east edge of figure 10 (north half) and east and north of figure 10 drains to north oriented Beaver Creek. A southeast and east oriented Ninemile Draw tributary originates near the northwest corner of section 34 and drains through Chugwater Reservoir. This southeast oriented tributary and other south oriented streams south of Ninemile Hill (in section 26) probably eroded headward from a former south oriented drainage route on the Ninemile Draw alignment. South Fork Ballenger Draw originates in section 33 and drains in a north-northeast direction to Red Lake before turning to drain in a northwest direction into section 29 where it turns again to drain in a west-southwest and west direction to the west edge of figure 10 (north of center). Note north and north-northeast oriented tributaries to the west-southwest oriented South Fork Ballenger Draw segment. The North Fork Ballenger Draw drains in a southwest direction across the northwest corner of figure 10 and joins the South Fork west of figure 10 to form southwest oriented Ballenger Draw, which drains to north-northwest oriented Government Draw as a barbed tributary. Fivemile Draw is the north and southwest oriented Government Draw tributary in the southwest quadrant of figure 10. The north oriented headwaters and tributaries to southwest oriented Fivemile Draw and west-southwest oriented South Fork Ballenger Draw segment were probably formed by reversals of flood flow on south oriented flood flow channels beheaded by headward erosion of the Fivemile Draw and South Fork Ballenger Draw valleys. The Fivermile Draw and Ballenger Draw (both South and North Forks) valleys probably eroded headward from a south oriented flood flow channel on the Government Draw alignment and then were captured when flood flow on the Government Draw alignment was beheaded and reversed. Contour lines in figure 10 are again difficult to read, but Ninemile Hill in section 26 reaches an elevation greater 5940 feet. Elevation near the east edge of section 6 reach at least 5974 feet. Between section 6 and Ninemile Hill the Government Draw-Ninemile Draw drainage divide decreases to an elevation of between 5820 and 5840 feet near the corner of sections 27, 28, 33, and 34. This decrease in elevation defines a 100-foot deep through valley linking the northwest oriented South Fork Ballenger Draw valley segment with the southeast oriented Ninemile Draw tributary headwaters valley. The through valley was probably eroded by southeast oriented flood flow prior to the reversal of flood flow in the region and was beheaded by headward erosion of the deeper South Fork Ballenger Draw valley. Similar through valleys are common and cross many Wind River Basin drainage divides. These through valleys can be used to reconstruct flood flow routes prior to development of the present day drainage routes. However, it must be remembered the Wind River Basin was deeply eroded, first by south oriented flood flow and later by north oriented flood flow so any through valleys on the Wind River Basin floor were eroded late in the erosion process.

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.