Abstract:

This essay uses topographic map evidence to interpret landform origins in the Bates Creek-Little Medicine Bow River drainage divide area near the Wyoming Shirley Basin. Tributaries to the south and west oriented Little Medicine Bow River drain the Shirley Basin area, which is located south of the northwest end of the southeast and south oriented Laramie Mountains and north and east of the Shirley Mountains. The Little Medicine Bow River flows to the northwest, west, and northwest oriented Medicine Bow River, which in turn flows south of the Shirley Mountains to the north, north-northeast, and northeast oriented North Platte River, which flows west of the Shirley Mountains to where it turns to flow in an east and south direction around the northwest end of the Laramie Mountains to flow in a southeast direction on the east side of the Laramie Mountains. North of the Little Medicine Bow River headwaters from east to west are headwaters of north-northeast oriented Box Elder Creek, north oriented Deer Creek, northwest oriented Bates Creek, north and northwest oriented Stinking Creek, and northwest, west, southwest, and south-southwest oriented Dry Creek, all of which flow to the North Platte River. Box Elder Creek and Deer Creek flow from the Shirley Basin area in deep valleys across the Laramie Mountains to join the east oriented North Platte River north of the Laramie Mountains. Bates Creek and Stinking Creek join the north-northeast North Platte River segment south and west of the Laramie Mountains northwest end. Dry Creek flows to west oriented Sage Creek, which joins the north-oriented North Platte River segment west of the Shirley Mountains. Drainage routes and valleys in the Shirley Basin area are interpreted in the context of immense melt water floods from the western margin of a thick North American ice sheet, which were flowing from western Canada to and across Wyoming at a time when Wyoming mountain ranges were emerging. All north oriented drainage routes including the north oriented North Platte River segment originated as south oriented flood flow channels. Headward erosion of a much deeper southeast oriented North Platte River valley around the northwest end of the emerging Laramie Mountains beheaded south oriented flood flow channels crossing the Shirley Basin area in sequence from east to west. Floodwaters on the Box Elder and Deer Creek alignments were beheaded first and floodwaters on north ends of the beheaded flood flow channels reversed flow direction to flow to the much deeper east, south, and southeast oriented North Platte River valley. The reversed flood flow channels captured southeast and south oriented flood flow still moving on the Bates Creek, Stinking Creek, and Dry Creek alignments. This captured flood flow made U-turns in the Shirley Basin area to flow to the much deeper North Platte River valley. Continued headward erosion of the North Platte River valley next beheaded and reversed flood flow on the Bates Creek and Stinking Creek alignments, which captured southeast and south oriented flood flow on the Dry Creek and North Platte River alignments (north and west of the Shirley Mountains). Finally headward erosion of the much deeper North Platte River valley and tributary valleys beheaded and reversed additional flood flow flood flow channels to create the present day northwest, west, and southwest oriented Dry Creek drainage route and the north, north-northeast, northeast, east, south, and southeast oriented North Platte River drainage route seen today.

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 Bates Creek-Little Medicine Bow River drainage divide area landform origins near the Wyoming Shirley Basin. 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 Bates Creek-Little Medicine Bow River drainage divide area landform evidence near the Wyoming Shirley Basin will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Bates Creek-Little Medicine Bow River drainage divide area location map

Figure 1: Bates Creek-Little Medicine 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 Bates Creek-Little Medicine Bow River drainage divide area near the Wyoming Shirley Basin and illustrates a region in central Wyoming. The Laramie Mountains extend in a southeast and south direction from near Casper to the south edge of figure 1 (east of center). The North Platte River flows in a northwest and northeast direction from the south edge of figure 1 (near southwest corner) to the south end of Seminoe Reservoir and then in a north direction to Pathfinder Dam. From Pathfinder Dam the North Platte River flows in a north-northeast and northeast direction to Casper. From Casper the North Platte River continues in an east, south, and southeast direction to the east center edge of figure 1. The Medicine Bow River flows in a northeast and northwest direction from the south edge of figure 1 (near town of Elk Mountain) to the town of Medicine Bow. From Medicine Bow the Medicine Bow River flows in a northwest, west, and northwest direction to join the north oriented North Platte River at Seminoe Reservoir. Shirley Basin (the community) is labeled and is located near the center of figure 1. The unlabeled west, south-southwest, southeast, south, and west oriented stream near Shirley Basin is the Little Medicine Bow River, which joins the Medicine Bow River near the town of Medicine Bow. Muddy Creek is an east, south-southeast, and south oriented tributary to the west oriented Little Medicine Bow River segment. The unlabeled northwest oriented North Platte River tributary originating north of Shirley Basin is Bates Creek. Stinking Creek is the unlabeled north and northwest oriented tributary originating north of the Muddy Creek headwaters and joins Bates Creek a short distance before Bates Creek joins the north oriented North Platte River. Box Elder Creek is a north-northeast oriented North Platte River tributary originating north of the Little Medicine Bow River headwaters and flows across the Laramie Mountains in a deep valley. Deer Creek is the unlabeled north and north-northeast stream west of Box Elder Creek, which also originates north of the Little Medicine Bow River headwaters and which flows across the Laramie Mountains (also in a deep valley) to join the North Platte River near Glen Rock. Dry Creek is an unlabeled northwest, west, southwest, and west oriented stream originating north of the Muddy Creek headwaters and joins the north oriented North Platte River near Kortes Dam (the final west oriented segment is Sage Creek on more detailed maps and Kortes Dam is actually located south of Pathfinder Reservoir). The Bates Creek-Little Medicine Bow River drainage divide area investigated in this essay is primarily located south of the Dry Creek, Stinking Creek, Bates Creek, and Deer Creek headwaters and north of the Muddy Creek and Little Medicine Bow River headwaters.

Bates Creek-Little Medicine Bow River drainage divide area landforms developed during immense melt water floods, which flowed from the western margin of a thick North American ice sheet in western Canada to and across Wyoming. At the time floodwaters crossed Wyoming mountain ranges were beginning to emerge and for a time floodwaters flowed across what are today high mountain barriers. North oriented North Platte River, Stinking Creek, Bates Creek, Deer Creek, and Box Elder Creek drainage routes originated as south oriented flood flow channels and were beheaded and reversed in sequence from east to west by headward erosion of the much deeper southeast oriented North Platte River valley around the emerging Laramie Mountains. The south and southeast oriented floodwaters on the Stinking Creek, Bates Creek, Deer Creek, and Box Elder Creek alignments were flowing to south oriented flood flow channels on the present day south oriented Muddy Creek and Little Medicine Bow River alignments, which converged with southeast, east, and southeast oriented flood flow on the present day northwest, west, and northwest oriented Medicine Bow River alignment to form southeast and east oriented flood flow channels leading to flood flow channels on the alignments of the east and northeast oriented Laramie River and tributaries, which were eroding deep valleys across the emerging Laramie Mountains to reach the much deeper southeast oriented North Platte River valley east of figure 1. As the deep southeast oriented North Platte River valley eroded headward along the northeast side of the Laramie Mountains it eventually beheaded a south-southwest oriented flood flow channel on the present day Box Elder Creek alignment. Floodwaters on the Box Elder Creek alignment reversed flow direction to flow to the much deeper southeast oriented North Platte River valley and captured flood flow from south and southeast oriented flood flow channels further to the west. These captured floodwaters made U-turns to flow in a north-northeast direction across the emerging Laramie Mountains so as to reach the deep southeast oriented North Platte River valley. Next headward erosion of the deep North Platte River valley beheaded and reversed south oriented flood flow on the present day north oriented Deer Creek alignment and again reversed flood flow captured southeast and south oriented flood flow from flood flow routes further to the west. Headward erosion of the deep southeast oriented North Platte River valley around the northwest end of the emerging Laramie Mountains then began to behead and reverse south and southeast oriented flood flow channels west of the Laramie Mountains. This process of beheading and reversing flood flow channels west of the Laramie Mountains took place in multiple steps and over time resulted in the creation of the north, north-northeast, and northeast oriented North Platte River drainage route west of the Laramie Mountains seen today. Southeast oriented flood flow on the present day northwest oriented Bates Creek alignment was beheaded and reversed while floodwaters were still flowing in a south direction on the North Platte River alignment west of the Shirley Mountains. As the deep North Platte River valley continued to behead and reversed flood flow channels there were additional flood flow reversals and flood flow direction changes. Further complicating flood flow movements and assisting in the flood flow reversal process was ice sheet related crustal warping that was raising the regional mountain ranges and the entire region and that may have been raising the Shirley Basin area as floodwaters flowed across the region.

Detailed location map for Bates Creek-Little Medicine Bow River drainage divide area

Figure 2: Detailed location map for Bates Creek-Little Medicine Bow River 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 Bates Creek-Little Medicine Bow River drainage divide area near the Wyoming Shirley Basin. The green colored areas are National Forest lands, which in figure 2 are located in the Laramie Mountains. The North Platte River flows in a north-northeast direction across the northwest corner of figure 2 and north of figure 2 flows around the northwest end of the Laramie Mountains and then flows in a south and east direction across the northeast corner of figure 2. The Shirley Basin is labeled and is located in the southwest quadrant of figure 2. The North Fork Little Medicine Bow River originates near the center of figure 2 and flows in a northwest, south-southwest, and southwest direction to join southeast oriented Spring Creek (at east end of the Shirley Basin) to form the south oriented Little Medicine Bow River, which flows to the south edge of figure 2 (west of center). South of figure 2 the Little Medicine Bow River turns to flow in a west direction to join the northwest, west, and northwest oriented Medicine Bow River, which joins the north oriented North Platte River (west of figure 2). Bates Creek Reservoir is located slightly west of the center of figure 2 and is north of the Shirley Basin. Bates Creek flows in a northwest direction from Bates Creek Reservoir to join the North Platte River near the northwest corner of figure 2. Bates Hole is labeled and is a deep north oriented valley located in the west center region of figure 2. Stinking Creek originates near Chalk Mountain and flows in a north direction through Bates Hole and then turns in a northwest direction to join Bates Creek, which then joins the north-northeast oriented North Platte River. Dry Creek is the northwest and west oriented stream directly south of Chalk Mountain and west of figure 2 flows in a southwest and west direction to join the north oriented North Platte River. Box Elder Creek is a north-northeast oriented stream originating near the center of figure 2 (north of the North Fork Little Medicine Bow River headwaters), which flows across the Laramie Mountains to the north edge of figure 2 (east of center). North of figure 2 Box Elder Creek joins the east, south, and southeast oriented North Platte River. Deer Creek is a south, southwest, and north oriented stream located west of the Box Elder Creek headwaters and the Deer Creek U-turn is located east of Bates Hole Reservoir. Deer Creek flows to north center edge of figure 2 and north of figure 2 flows to the east, south, and southeast oriented North Platte River.

Bates Creek-North Fork Little Medicine Bow River drainage divide area

Figure 3: Bates Creek-Little Medicine Bow River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of Bates Creek-Little Medicine Bow River drainage divide area. The map contour interval for figure 3 is 20 meters. The Laramie Mountains are located in the northeast corner area of figure 3. Box Elder Creek flows in a southwest direction from the east edge of figure 3 (slightly north of center) and then turns to flow in a north-northeast direction to the northeast corner of figure 3. North and east of figure 3 Box Elder Creek flows across the Laramie Mountains in a deep valley (partly seen in figure 3) to the east, south, and southeast oriented North Platte River. Deer Creek flows in a south and southwest direction from the north edge of figure 3 (east half) and then turns to flow in a north direction to the north center edge of figure 3. North of figure 3 Deer Creek flows in a deep valley across the Laramie Mountains to the east, south, and southeast oriented North Platte River. Curry Creek is a southwest and northwest oriented stream in the east center area of figure 3 and joins southwest and northwest oriented Texas Creek, which then joins Deer Creek near the elbow of capture where Deer Creek turns to flow in a north direction. Bates Creek Reservoir is located along the west edge of figure 3 and Bates Creek flows in a west-northwest direction into Bates Creek Reservoir and then in a north and west direction to the west edge of figure 3 (north half). West of figure 3 Bates Creek flows in a northwest direction to join the north-northeast and northeast oriented North Platte River, which flows west of the northwest end of the Laramie Mountains before turning to flow in an east, south, and southeast direction along the north and east sides of the Laramie Mountains. East Fork Bates Creek flows in a west-northwest direction to join Bates Creek north of Bates Creek Reservoir and near the point where Bates Creek turns to flow in a west direction. The North Fork Little Medicine Bow River flows in west-northwest and south direction from the east edge of figure 3 (south half) to the south edge of figure 3 (east half) and south of figure 3 flows in a southwest direction to join other tributaries to form the south and west oriented Little Medicine Bow River, which flows to the northwest, west, and northwest oriented Medicine Bow River, which in turn flows to the north, north-northeast, northeast, east, south, and southeast oriented North Platte River. South oriented drainage routes flowing to the south edge of figure 3 (west of the North Fork Little Medicine Bow River) flow into the Shirley Basin and are North Fork Little Medicine Bow River tributaries or flow to southeast oriented Spring Creek, which joins the North Fork Little Medicine Bow River to form the south and west oriented Little Medicine Bow River. Drainage routes seen in figure 3 developed as immense south oriented floods flowed across and around the emerging Laramie Mountains to the south oriented flood flow channels in Little Medicine Bow River drainage basin, which at that time converged with southeast and east oriented flood flow channels on the present day west and northwest oriented Medicine Bow River alignment to move floodwaters across the emerging Laramie Mountains in east and northeast Laramie River and tributary valleys to the deep southeast oriented North Platte River valley east of the Laramie Mountains. Headward erosion of the southeast oriented North Platte River valley around the northwest end of the Laramie Mountains then beheaded and reversed the flood flow channels supplying floodwaters to the region seen in figure 3. The reversal of flood flow on the Box Elder Creek alignment captured south and southeast oriented flood flow still moving on the Deer Creek and Bates Creek alignments. Next the reversal of flood flow on the Deer Creek alignment captured southeast oriented flood flow still moving on the Bates Creek alignment. Finally headward erosion of the deep North Platte River valley around the northwest end of the Laramie Mountains beheaded and reversed flood flow on the Bates Creek alignment and the process continued as flood flow channels were beheaded.

Detailed map of Curry Creek-North Fork Little Medicine Bow River drainage divide area

Figure 4: Detailed map of Curry Creek-North Fork Little Medicine Bow River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 4 provides a detailed topographic map of the Curry Creek-North Fork Little Medicine Bow River drainage divide area seen in less detail in figure 3. The map contour interval for figure 4 is 10 feet. The North Fork Little Medicine Bow River flows in a west and southwest direction from the east edge of figure 4 in section 36 (south half) to the south edge of figure 4. South of figure 4 the North Fork Little Medicine Bow River flows in a southwest direction to join southeast oriented Spring Creek and to form the south and west oriented Little Medicine Bow River, which flows to the northwest, west, and northwest oriented Medicine Bow River, which in turn flows to north, north-northeast, northeast, east, south, and southeast oriented North Platte River. South oriented streams flowing to the south edge of figure 4 (west of the North Fork Little Medicine Bow River) south of figure 4 flow to the North Fork Little Medicine Bow River. Curry Creek flows in a southwest direction from near the northeast corner of figure 4 into the south margin area of section 23 and then turns to flow in a northwest direction to join southwest and northwest oriented Texas Creek (just east of the north center edge of figure 4). North of figure 4 Texas Creek flows to north oriented Deer Creek, which flows across the Laramie Mountains in a deep valley to join the east, south, and southeast oriented North Platte River on the north side of the Laramie Mountains. Northwest oriented drainage routes in the northwest corner region of figure 4 flow to northwest oriented Bates Creek, which flows to the north-northeast, northeast, east, south, and southeast oriented North Platte River (which flows around the northwest end of the Laramie Mountains). A through valley in the southwest corner of section 29 links a north-northeast and north-northwest oriented Deer Creek tributary valley with a south oriented North Fork Little Medicine Bow River tributary valley. The through valley floor elevation is between 7630 and 7640 feet. Elevations in section 31 to the west rise to 7713 feet and elevations on Dugway Rim to the east rise to more than 7810 feet suggesting the through valley is at least 73 feet deep. The through valley and the south-facing escarpment were eroded by south oriented flood flow prior to the reversal of flood flow on the Deer Creek alignment to the north of figure 4. Other through valleys eroded by south oriented flood flow prior to the beheading and reversal of south oriented flood flow channels supplying floodwaters to the region in figure 4 are found in northwest corner of section 35 and the southeast corner of section 26 and link the northwest oriented Curry Creek valley with south oriented North Fork Little Medicine Bow River tributary valleys. A west to east oriented through valley in section 21 links the north-northeast and north-northwest oriented Deer Creek valley with the southwest and northwest oriented Texas Creek valley. North and east of figure 4 the southwest oriented Texas Creek headwaters valley is linked by a through valley with the north-northeast oriented Box Elder Creek valley. The west to east oriented through valley was eroded by south and southeast oriented flood flow on the present day Bates and Deer Creek alignments flowing to the newly beheaded and reversed flood flow on the north-northeast oriented Box Elder Creek alignment (which was beheaded and reversed prior to the beheading and reversal of flood flow on the Deer Creek alignment, which occurred before the beheading and reversal of flood flow on the Bates Creek alignment).

Bates Creek-Deer Creek drainage divide area

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

Figure 5 illustrates a topographic map of the Bates Creek-Deer Creek drainage divide area north and slightly west of figure 3 and includes an overlap area with figure 3. The map contour interval for figure 5 is 20 meters. Bates Creek Reservoir is located near the southwest corner of figure 5. Bates Creek flows in a west-northwest direction from near the south center edge of figure 5 to Bates Creek Reservoir and then in a north and west direction to the west edge of figure 5 (slightly south of center). West of figure 5 Bates Creek flows in a northwest direction to join the north-northeast oriented North Platte River, which then flows in a northeast, east, south, and southeast direction around the northwest end of the Laramie Mountains. Box Elder Creek flows in a north-northeast direction across the southeast corner of figure 5. Deer Creek originates in the east center area of figure 5 and flows in a south, southwest, and west direction to near the county line and then flows in a north, north-northeast, and north direction to the north edge of figure 5 (east half). North of figure 5 Deer Creek flows to the east, south, and southeast oriented North Platte River. The Upper Deer Creek Canyon where Deer Creek crosses the Laramie Mountains is more than 400 meters deep and is a deep water gap, which was initially eroded by south oriented flood flow. After headward erosion of the deep North Platte River valley (to the north of figure 5) beheaded and reversed flood flow on the Deer Creek alignment the reversed flood flow captured southeast oriented flood flow still moving on the Bates Creek alignment and continued to erode the deep Upper Deer Creek Canyon valley. A through valley north of the south center edge of figure 5 links the west-northwest East Fork Bates Creek valley with the north oriented Deer Creek valley. The through valley floor elevation is between 2300 and 2320 meters. Elevations on the south-facing escarpment rim to the south of figure 5 rise to more than 2350 meters suggesting the through valley is at least 30 meters deep. What has happened here is south oriented flood flow eroded the south-facing escarpment seen in figures 3 and 4 and then reversals of flood flow on the Box Elder Creek and the Deer Creek alignments captured southeast oriented flood flow on the Bates Creek alignment, which then eroded the north-facing slope on the north side the south-facing escarpment rim as the floodwaters made U-turns to flow in north directions to the much deeper east, south, and southeast North Platte River valley located north of the Laramie Mountains (and north of figure 5).

Detailed map of East Fork Bates Creek-Deer Creek drainage divide area

Figure 6: Detailed map of East Fork Bates Creek-Deer 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 East Fork Bates Creek-Deer Creek drainage divide area seen in less detail in figure 5. The map contour interval for figure 6 is 10 feet. Deer Creek flows in a west direction from the east edge of figure 6 (near southeast corner) into section 16 and then turns to flow in a north, north-northeast, and north direction to the north edge of figure 6 (near northeast corner). North of figure 6 Deer Creek flows across the Laramie Mountains in deep Upper Deer Creek Canyon to reach the east, south, and southeast oriented North Platte River. The East Fork Bates Creek flows in a west-northwest direction from northwest quadrant of section 18 (near south center edge of figure 6) to the west edge of figure 6 and west of figure 6 joins west and northwest oriented Bates Creek, which flows to the north-northeast oriented North Platte River, which then flows in a northeast, east, south, and southeast direction around the northwest end of the Laramie Mountains. The rim of the south-facing escarpment near the south edge of figure 6 (west of section 17) separates the west-northwest oriented East Fork Bates Creek valley from the west-northwest oriented Bates Creek valley to the south of figure 6. West to east oriented through valleys in the northeast corner of section 18, the northeast corner of section 7, and the northeast quadrant of section 6 link the west-northwest oriented East Fork Bates Creek valley with the north oriented Deer Creek valley. The through valleys are today 50 feet or less in depth, but they provide evidence of what were once diverging and converging east oriented flood flow channels moving southeast oriented floodwaters from the present day northwest oriented Bates Creek alignment (to the west of figure 6) to a newly beheaded and reversed north oriented flood flow channel on the Deer Creek alignment. South of figure 6 floodwaters moved in an east direction from the west-northwest oriented Bates Creek headwaters valley alignment to a beheaded and reversed north-northeast oriented flood flow channel on the Box Elder Creek alignment. The ridge along the south edge of figure 6 separating the East Fork Bates Creek headwaters valley from the Bates Creek headwaters valley was formed as floodwaters flowed to the two different beheaded and reversed flood flow channels. The escarpment rims seen in figures 3,4, 5, and 6 may also represent hogback ridges, although floodwaters making U-turns in the region eroded the valleys between the hogback ridges.

Bates Creek-Stinking Creek drainage divide area

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

Figure 7 illustrates the Bates Creek-Stinking Creek drainage divide area south and west of figure 3 and includes an overlap area with figure 3. The map contour interval for figure 7 is 20 meters. Bates Creek Reservoir is located near the northeast corner of figure 7. Chalk Mountain is located near the southwest corner of figure 7. Stinking Creek originates in the southwest quadrant of figure 7 (east of Chalk Mountain) and flows in a north and then north-north-northwest direction through Bates Hole to the north edge of figure 7. North of figure 7 Stinking Creek flows in a north and northwest direction to join west and northwest Bates Creek, which then joins the north-northeast oriented North Platte River. Moss Agate Ridge is located in the southeast quadrant of figure 7 and separates the east-southeast oriented Spring Creek headwaters from the northeast and southeast oriented Sand Creek drainage basin to the south (Sand Creek is located south of figure 7). The Bates Hole floor elevation is approximately 300 meters lower than the elevation of the Bates Creek Reservoir to the east and Bates Hole is a deep north-northwest oriented valley eroded into the regional landscape. In terms of sequence of events south oriented flood flow on the Stinking Creek alignment was beheaded and reversed after flood flow on the Bates Creek, Deer Creek, and Box Elder Creek alignments to the northeast of figure 7 had been beheaded and reversed, but before flood flow channels west of figure 7 were beheaded and reversed. This sequence means most water that eroded the deep north oriented Bates Hole valley first moved in a south direction to the west of figure 7, perhaps on the present day north oriented North Platte River alignment. As seen in figures 8 and 9 some of this flood flow may have reached the south end of the deep Bates Hole valley via the present day northwest and west oriented Dry Creek alignment although a another route could have been the floodwaters flowed south direction on alignments of present day north oriented drainage routes west of figure 7 to an east oriented valley on the north side of the Shirley Mountains now drained by the west oriented Middle Fork Sage Creek and its Cave Creek tributary (seen in figure 9).  Floodwaters would have moved in an east direction on the alignment of that valley to the region south of Chalk Mountain (again seen in figure 9) to reach what is now the south end of the deep north oriented Bates Hole valley. Before the erosion of the deep north oriented Bates Hole valley and the deep Muddy Creek valley to the south of figure 7 floodwaters flowed in northeast and east directions to the Bates Creek Reservoir area and also to what are today the Spring Creek and Sand Creek headwaters area. The reversal of flood flow on the Stinking Creek alignment captured at least some of that east and northeast oriented flood flow and diverted the floodwaters in a north direction. As the deep Bates Hole valley eroded headward into the region it beheaded and reversed a northeast oriented flood flow channel (crossing the Bates Creek Reservoir area) causing the reversed floodwaters to flow in a southwest direction into the much deeper Bates Hole valley and to erode the southwest oriented Lone Tree Creek valley (near center of figure 7).

Stinking Creek-Muddy Creek drainage divide area

Figure 8: Stinking Creek-Muddy 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 Stinking Creek-Muddy Creek drainage divide area south and west of figure 7 and includes an overlap area with figure 7. The map contour interval for figure 8 is 20 meters. Moss Agate Ridge is located near the northeast corner of figure 8. Chalk Mountain is located near the northwest corner of figure 8. The north oriented stream east of Chalk Mountain (near the highway) is Stinking Creek, which north of figure 8 flows in a north and northwest direction to join west and northwest oriented Bates Creek, which then joins the north-northeast oriented North Platte River. The deep north oriented Stinking Creek valley east of Chalk Mountain is the south end of Bates Hole. The Shirley Basin is located south and east of Bates Hole and is drained in figure 8 by east-northeast and east-southeast oriented Sand Creek and its tributaries. East of figure 8 Sand Creek flows to the south and west oriented Little Medicine Bow River, which flows to the northwest, west, and northwest oriented Medicine Bow River, which in turn flows to the north, north-northeast, northeast, east, south, and southeast oriented North Platte River. The south-facing escarpment near the south edge of figure 8 is the rim of the east and south oriented Muddy Creek drainage basin, which is roughly 100 meters lower in elevation than the floor of the Sand Creek drainage basin to the north. Dry Creek is the northwest oriented stream originating in the west center region of figure 8 and flows to west edge of figure 8 (to the west of Chalk Mountain). West of figure 8 Dry Creek flows in a northwest, west, southwest, and south-southwest direction to join west oriented Sage Creek, which then flows to the north oriented North Platte River. The deep north oriented Bates Hole (or Stinking Creek valley) and the deep east and southeast oriented Muddy Creek drainage basin provide evidence of the headward erosion of deep valleys from two completely different directions into the region seen in figure 8 to capture east-northeast oriented floodwaters flowing on what is now the Sand Creek drainage basin surface (or the Shirley Basin surface). Floodwaters appear to have been coming from west and south of figure 8, although it is possible floodwaters also moved in a southeast direction on the present day northwest oriented Dry Creek alignment. Headward erosion of the deep Muddy Creek valley beheaded the east-northeast oriented flood flow routes to the present day Sand Creek drainage basin while a reversal of flood flow on the Dry Creek alignment created the present day northwest oriented Dry Creek drainage route.

Dry Creek-Muddy Creek drainage divide area

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

Figure 9 illustrates the Dry Creek-Muddy Creek drainage divide area south and west of figure 8 and there is an overlap area with figure 8. The map contour interval for figure 9 is 20 meters. The northeast end of the Shirley Mountains can be seen along the south edge of the southwest quadrant of figure 9. Cave Creek flows in a north direction from the south edge of figure 9 (in the Shirley Mountains) and then turns to flow in a west direction to flow to the west edge of figure 9. West of figure 9 Cave Creek joins west oriented Middle Fork Sage Creek, which flows to west oriented Sage Creek, which then flows to the north oriented North Platte River. Fourmile Point is a labeled high point north of the Cave Creek elbow of capture (where Cave Creek turns to flow in a west direction). Fourmile Point is located at the east end of Fourmile Ridge, which appears to be a hogback ridge on the north side of the west oriented Cave and Middle Fork Sage Creek valley. Fourmile Creek originates east of Fourmile Point and flows in a north direction to join northwest and west oriented Dry Creek, which flows to the west edge of figure 9 (near northwest corner). West of figure 9 Dry Creek turns to flow in a southwest and south-southwest direction to join west oriented Sage Creek. North of the west oriented Dry Creek valley segment Dry Creek Ridge straddles the north edge of figure 9. The south end of Chalk Mountain is located along the north edge of figure 9 (east of center and north of the northwest oriented Dry Creek headwaters). The south end of the north oriented Stinking Creek valley (Bates Hole) is located east of Chalk Mountain. The deep east oriented Muddy Creek drainage basin is located in the south half of figure 9 (east of the Shirley Mountains). North of the Muddy Creek drainage basin and east of the Dry Creek headwaters are the east-northeast oriented Sand Creek headwaters flowing on the upland Shirley Basin surface. Probably before the reversal of flood flow on the present day north oriented North Platte River alignment (west of figure 9) floodwaters moved in an east direction on the present day west oriented Sage Creek, Middle Fork Sage Creek, and Cave Creek valley segments between the Shirley Mountains to the south and Fourmile Ridge to the north (and perhaps on the present day west oriented Dry Creek valley alignment) to reach the east-northeast oriented Sand Creek headwaters, but were captured by the actively eroding north oriented Stinking Creek valley (Bates Hole) and by the actively eroding east oriented Muddy Creek valley, both of which were much deeper than the Sand Creek drainage basin surface. A reversal of flood flow on the Dry Creek alignment created the northwest and west oriented Dry Creek drainage route. Flood flow movements in this region were also affected by crustal warping occurring as floodwaters flowed across the region.

Detailed map of Dry Creek-Muddy Creek drainage divide area

Figure 10: Detailed map of Dry Creek-Muddy Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 10 provides a detailed topographic map of the Dry Creek-Muddy Creek drainage divide area seen in less detail in figure 9. The map contour interval for figure 10 is 20 feet. Dry Creek originates in section 29 and flows in a north-northwest direction to the north edge of figure 10 (west of center). North of figure 10 Dry Creek flows in a northwest, west, southwest, and south-southwest direction to join west oriented Sage Creek, which then flows to the north, north-northeast, northeast, east, south, and southeast North Platte River. Northeast and east-northeast drainage routes flowing to the east edge of figure 10 are headwaters of east-southeast and southeast oriented Sand Creek, which flows to the south and west oriented Little Medicine Bow River, which flows to the northwest, west, and northwest oriented Medicine Bow River, which flows to the north oriented North Platte River. The south-facing escarpment marks the north edge of the east, southeast, and south oriented Muddy Creek drainage basin, which drains to the west oriented Little Medicine Bow River. Note in section 29 how a northwest oriented Dry Creek headwaters stream is flowing along the rim of the south-facing escarpment. The Dry Creek-Muddy Creek drainage divide elevation at that point is between 7360 and 7380 feet. Elevations in the north center margin of section 36 to the west rise to 7515 feet while elevations near the north edge of section 32 to the south rise to 7465 feet. These elevations suggest there is a through valley (today a hanging through valley) in section 29 that is at least 85 feet deep.  The through valley was probably eroded by south-southeast oriented flood flow moving from the present day north-northwest oriented Dry Creek valley to erode the deep southwest and south-southwest oriented Muddy Creek tributary valley to the west of the north-northwest oriented Dry Creek headwaters valley. However, there are similar indentations into the south-facing escarpment not linked with present day through valleys. These indentations almost certainly were eroded by south oriented flood flow moving to the deeper east, southeast, and south oriented Muddy Creek drainage basin. Erosion of the other indentations suggests floodwaters flowed on a surface at least as high as some of the highest points on the escarpment rim today. Floodwaters may have been making U-turns in this region from flowing in a south-southeast on the Dry Creek alignment to flowing in east-northeast directions to the Sand Creek drainage basin and perhaps to flowing in a north direction to the newly beheaded and reversed Stinking Creek drainage route (which was eroding the deep Bates Hole valley).  If so the more significant through valleys may be in sections 17 and 20 where east-northeast oriented Sand Creek headwaters valleys are linked with west-southwest oriented Dry Creek tributary valleys. These through valleys have floor elevations of between 7340 and 7360 feet (slightly lower than the section 29 through valley elevation), which suggests floodwaters were still making U-turns on the relatively narrow upland strip between the deep north oriented Stinking Creek valley and the deep east, southeast and south oriented Muddy Creek drainage basin to the south right up until the time floodwaters on the Dry Creek alignment were beheaded and reversed to create the north-northwest oriented Dry Creek drainage route seen in figure 10.

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.