Abstract:

This essay uses topographic map evidence to identify north to south and northwest to southeast oriented through valleys crossing the Sweetwater River-Great Divide Basin drainage divide in the region between the Wind River Range to the west and Crooks Mountain to the east. North of the Sweetwater River segment investigated is the Wind River Basin and the north oriented Wind-Bighorn River, which flows to the northeast oriented Yellowstone River. The Great Divide Basin is a region of internal drainage in south central Wyoming bounded on the north by the east-northeast and east oriented Sweetwater River drainage basin and on the south by the west and southwest oriented Little Snake River drainage basin. East of the Great Divide Basin is the north oriented North Platte River drainage basin and west of the Great Divide Basin is the south oriented Green River drainage basin. The Sweetwater River flows to the north oriented North Platte River, which further north turns to flow in an east and southeast direction around the Laramie Mountains northwest end and to flow into Nebraska with water eventually reaching the Gulf of Mexico. The Little Snake River flows to the west oriented Yampa River, which then flows to the south oriented Green River, which flows to the southwest oriented Colorado River and then the Pacific Ocean. The through valleys are interpreted to have been eroded as south and southeast oriented flood flow channels, which continued across the present day Great Divide Basin to what were at that time actively eroding Little Snake River and tributary valleys. Floodwaters were derived from the western margin of a thick North American ice sheet and were flowing from western Canada to and across the Great Divide Basin at a time when Montana, Wyoming, and Colorado mountain ranges were emerging. Mountain ranges emerged as floodwaters deeply eroded basins and valleys surrounding them and as ice sheet related crustal warping raised the mountain ranges. Headward erosion of the deep southeast and east oriented North Platte River valley around the northwest end of the Laramie Mountains beheaded a south oriented flood flow channel on the present day north oriented North Platte River alignment. Floodwaters on the north end of the beheaded flood flow route reversed flow direction to flow to the much deeper east and southeast oriented North Platte River valley and created the north oriented North Platte River drainage route. South oriented flood flow west of the newly reversed North Platte River drainage route was captured by headward erosion of the east and east-northeast oriented Sweetwater River valley. At about the same time headward erosion of the deep northeast oriented Yellowstone River valley in Montana beheaded a south oriented flood flow channel on the present day north oriented Wind River-Bighorn River alignment. The northeast oriented Yellowstone River valley was eroding headward from space at the south end of the deep “hole” the melting ice sheet was opening up. Floodwaters on the north end of the beheaded flood flow channel reversed flow direction to flow to the much deeper Yellowstone River valley and to create the north oriented Wind-Bighorn River drainage route. Creation of the north oriented Wind-Bighorn River drainage route ended all south and southeast oriented flood flow to and across the Great Divide 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 Sweetwater River-Great Divide Basin drainage divide area landform origins west of Crooks Mountain, 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 Sweetwater River-Great Divide Basin drainage divide area landform evidence west of Crooks Mountain, Wyoming will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Sweetwater River-Great Divide Basin drainage divide area location map

Figure 1: Sweetwater River-Great Divide Basin 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 Sweetwater River-Great Divide Basin drainage divide area west of Crooks Mountain and illustrates a region in south central Wyoming with Colorado and Utah being located south of Wyoming (Utah is in the southwest corner of figure 1). The Great Divide Basin is labeled and is a region of interior drainage in south central Wyoming. East of the Great Divide Basin the North Platte River flows in a north-northwest direction from south of figure 1 between the Sierra Madre and Medicine Bow Mountains and turns in the Pathfinder Reservoir area to flow in a north and northeast direction to Casper at the Laramie Mountains northwest end. A Casper the North Platte River turns to flow in an east, south, and east direction to the east edge of figure 1. East of figure 1 the North Platte River flows in a southeast direction into Nebraska with water eventually reaching the Gulf of Mexico. The Sweetwater River originates in the Wind River Range (in northwest quadrant of figure 1) and flows in a south-southeast direction to South Pass. Near South Pass the Sweetwater River turns to flow in an east-northeast and east direction north of the Great Divide Basin to join the North Platte River at Pathfinder Reservoir. Note how the Sweetwater River turns in a south direction just before it joins the north oriented North Platte River. West of the Great Divide Basin the Green River flows in a south-southeast direction from the west edge of figure 1 (north half) to the town of Green River and then in a south and east direction through the Flaming Gorge National Recreation Area before turning in a south direction to enter Dinosaur National Monument. At Dinosaur National Monument the Green River turns to flow in a southwest direction and south and west of figure 1 the Green River flows to the southwest Colorado River with water eventually reaching the Pacific Ocean. The Big Sandy River and its Little Sandy Creek tributary originate in the Wind River Range near the Sweetwater River headwaters and then flow in a south and south-southwest direction to join the Green River north of the town of Green River. The Yampa River is a west oriented tributary flowing from near Steamboat Springs, Colorado to join the Green River at Dinosaur National Monument.  The Little Snake River is a west and southwest oriented tributary joining the Yampa River near the east edge of Dinosaur National Monument. Muddy Creek is a south oriented tributary joining the Little Snake River near Baggs, Wyoming and drains the Great Divide Basin southern rim. Labeled drainage routes in the Great Divide Basin of interest in this essay are southeast oriented Bear Creek and south-southwest oriented Lost Creek, both of which end as surface streams in the Great Divide Basin. Crooks Mountain is not shown or labeled in figure 1, but is located west of the Green Mountains and north of Lost Creek. The Sweetwater River-Great Divide Basin drainage divide area investigated in this essay is generally located south of the east-northeast oriented Sweetwater River segment and north of Bear Creek and Lost Creek drainage basins.

Wyoming, Colorado, and Utah drainage routes evolved during immense melt water floods flowing from the western margin of a thick North American ice sheet in western Canada to and across the region seen in figure 1. At first Wyoming and other regional mountain ranges had not emerged and floodwaters were able to freely flow across what are today major mountain barriers. Mountain ranges emerged as floodwaters flowed across them, as ice sheet related crustal warping raised the mountain ranges, and as floodwaters eroded deep basins and valleys around the emerging mountain ranges. Ice sheet related crustal warping also created a deep “hole” in which the massive ice sheet was located. The north oriented North Platte River drainage route seen in figure 1 originated as a south oriented flood flow channel between emerging mountain ranges. Headward erosion of a deeper east and southeast oriented flood flow channel along the Laramie Mountains northeast flank and then along the Laramie Mountains north flank beheaded the south oriented flood flow channel on the present day north oriented North Platte River alignment. Floodwaters on the north end of the beheaded flood flow channel reversed flow direction to flow to the much deeper east and southeast oriented North Platte River valley north and east of the Laramie Mountains. This major flood flow reversal, which took place in multiple steps, was greatly aided by ice sheet related crustal warping that was raising mountain ranges in the present day North Platte River headwaters area. The east oriented Sweetwater River valley had initially eroded headward from the south oriented flood flow channel to capture south oriented flood flow in the region north of the emerging Ferris and Green Mountains, which accounts for the Sweetwater River turn in a south direction as it joins the north oriented North Platte River. The reversal of flood flow on the North Platte River alignment captured the east oriented flood flow moving in the newly eroded east oriented Sweetwater River valley.

Further to west another major south oriented flood flow channel developed east of the emerging Wind River Range and west of Crooks Mountain (west of the Green Mountains) and initially flowed across the present day Great Divide Basin to what at that time were actively eroding Little Snake River and tributary valleys with water then flowing to Green and Colorado Rivers. This western flood flow channel was beheaded in Montana by headward erosion of the much deeper northeast oriented Yellowstone River valley. The deep northeast oriented Yellowstone River valley eroded headward from space at the south end of the deep “hole” the melting ice sheet was opening up and that was being drained in a south direction across eastern Nebraska. Floodwaters on the north end of the beheaded flood flow channel reversed flow direction to flow in a north direction to the much deeper Yellowstone River valley and created the north oriented Wind-Bighorn River drainage route (north of figure 1). Reversed flood flow began to move in a north direction in the region between the Wind River Range and the Granite Mountains toward the newly reversed Wind-Bighorn River drainage route. The east-northeast oriented Sweetwater River valley then eroded headward as this flood flow reversal was taking place. Headward erosion of the east-northeast oriented Sweetwater River valley ended all flood flow movements across the Great Divide Basin and also captured south oriented flood flow still moving across the emerging Wind River Range southeast end. Ice sheet related crustal warping subsequently raised the region and the surrounding mountain ranges.

Detailed location map for Sweetwater River-Great Divide Basin drainage divide area

Figure 2: Detailed location map for Sweetwater River-Great Divide Basin 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 Sweetwater River-Great Divide Basin drainage divide area west of Crooks Mountain. The green colored in the northwest corner of figure 2 is National Forest land located in the Wind River Range. South Pass is located south of the green colored area near the west center edge of figure 2. The Sweetwater River flows in an east-northeast direction from South Pass to the north edge of figure 2 (near Sweetwater Station) and north and east of figure 2 joins the north and southeast oriented North Platte River. North of the Sweetwater River the east-southeast, east, and north oriented stream flowing through the town of Miners Delight (next to green colored area) is Beaver Creek, which north of figure 2 flows to the north oriented Wind-Bighorn River, which then flows to Montana and the northeast oriented Yellowstone River. Note how the Beaver Creek and Sweetwater River drainage routes come close together before diverging and going in quite different directions. Oregon Buttes are located south of South Pass and near the west edge of figure 2. The East Rim of the Great Divide Basin extends from near Oregon Buttes to Continental Peak and then south of Picket Lake, north of Cyclone Rim, and south of Buffalo Basin before reaching the east edge of figure 2 (north of center) and marks the boundary between drainage routes to the Gulf of Mexico and drainage routes that end or disappear in the Great Divide Basin. The Crooks Mountain location is labeled in the east half of figure 2 and is mostly drained by Sweetwater River tributaries. Alkali Creek is a major Sweetwater River tributary draining the Crooks Mountain area and is formed at the confluence of west-northwest oriented East Alkali Creek and northeast oriented West Alkali Creek. Sulphur Creek is an east-southeast and east-northeast oriented West Alkali Creek tributary originating the Antelope Hills. Picket Creek (not labeled in figure 2) originates in the Antelope Hills and flows in a south-southeast direction to near Picket Lake and then joins West Alkali Creek. South of the Great Divide Basin East Rim are headwaters of south oriented streams. Bear Creek originates near Oregon Buttes and flows in a southeast, east, and southeast direction to the south center edge of figure 2. South of figure 2 Bear Creek ends at Hay Reservoir next to the Red Desert Basin. South of Crooks Mountain Lost Creek and Lost Creek tributaries originate south of East Alkali Creek headwaters with Lost Creek flowing to the south edge of figure 2 (east half). South of figure 2 Lost Creek ends at Lost Creek Lake. South and west of South Pass along the west edge of figure 2 drainage is to the south oriented Green River and Pacific Ocean.

Oregon Gulch-Bear Creek drainage divide area

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

Figure 3 provides a topographic map of Oregon Gulch-Bear Creek drainage divide area. The map contour interval for figure 3 is 20 meters. Oregon Buttes is located in the southwest quadrant of figure 3. Edmund Springs is located near Oregon Buttes and Bear Creek originates at Edmund Springs and then flows in a southeast direction to the south center edge of figure 3. South of figure 3 Bear Creek joins other streams flowing into the Red Desert Basin region where the surface drainage routes end at Hay Reservoir. North of Edmund Springs are headwaters of east and northeast oriented Oregon Gulch, which drains to the north edge of figure 3 (slightly east of center). North of figure 3 Oregon Gulch drains to the east-northeast oriented Sweetwater River with water eventually reaching the Gulf of Mexico. Dickie Springs Creek is an east oriented Oregon Gulch tributary located near the north edge of figure 2. Continental Peak is a high point located south and east of the center of figure 3. North of Continental Peak are headwaters of east-southeast oriented Sand Creek, which flows to the east center edge of figure 3 and east and south of figure 3 Sand Creek joins other streams flowing to Hay Reservoir in the Great Divide Basin where the drainage route ends. The region between Oregon Buttes and Continental Peak was eroded by southeast oriented flood flow, which was beheaded by headward erosion of the deeper northeast oriented Oregon Gulch valley. The high point at Oregon Buttes is 2624 meters and the high point at Continental Peak is 2570 meters. Low points on the Oregon Gulch-Bear Creek drainage divide are in the 2340 -2360 meter range suggesting almost 200 meters of bedrock material has been stripped from the region. The similarity of elevations at the tops of these two buttes suggests the butte tops are remnants of a former erosion surface that once extended across the entire region. Deep south and southeast oriented flood flow channels eroded headward into the region and stripped the bedrock surface leaving isolated buttes such as Oregon Buttes and Continental Peak as markers to demonstrate what was once present. At the time floodwaters eroded the region there was no east-northeast oriented Sweetwater River valley north of figure 3 and the present day north oriented Wind-Bighorn River drainage route further to the north was a south oriented flood flow channel. While some of the south oriented floodwaters crossing the figure 3 region may have come from that south oriented Wind-Bighorn River flood flow channel at least some of the floodwaters were flowing across the present day Wind River Range, which means the Wind River Range at that time had not emerged as the high mountain range it is today.

Detailed map of Oregon Gulch-Bear Creek drainage divide area

Figure 4: Detailed map of Oregon Gulch-Bear 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 Oregon Gulch-Bear Creek drainage divide area seen in less detail in figure 3. The map contour interval for figure 4 is 20 feet. Oregon Buttes is located near the west edge of the southwest quadrant of figure 4. The high point on Oregon Buttes is 8612 feet. Edmund Springs are located in the southeast quadrant of section 35 (north and east Oregon Buttes). Bear Creek originates at Edmund Springs and flows in a southeast direction to the south center edge of figure 4. South of figure 4 Bear Creek joins other streams and flows to Hay Reservoir in the Red Desert Basin where the drainage routes end. Northeast oriented Oregon Gulch headwaters drain across section 35 (north of Edmund Springs) and drain to east-northeast oriented Oregon Gulch, which then drains to the north edge of figure 4 (east half). North of figure 4 Oregon Gulch drains to the east-northeast oriented Sweetwater River with water eventually reaching the Gulf of Mexico. The Oregon Gulch-Bear Creek drainage divide elevation in section 36 is between 7740 and 7760 feet. Continental Peak is located east of figure 4 and reaches an elevation 8431 feet. As previously discussed the region between Oregon Buttes and Continental Peak could be considered a former south oriented through valley. If viewed in that context the through valley was at least 670 feet deep (or approximately 670 feet of bedrock material has been eroded from the intervening area). However, looking at the floor of the broad through valley also reveals shallow through valleys crossing the drainage divide, which provide further support for the southeast oriented flood flow interpretation. For example, the low point on the Oregon Gulch-Bear Creek drainage divide in section 36 could be considered the floor of a former north to south oriented through valley. Continuing east from section 36 elevations on the drainage divide rise to more than 8000 feet in isolated buttes near the south edge of section 31. This very simple example seen completely in figure 4 shows a through valley that is at least 240 feet deep. Continuing further east more such through valleys can be found. These through valleys provide evidence of multiple south and southeast oriented flood flow channels that crossed the present day Sweetwater River-Great Divide Basin drainage divide.

Sweetwater River-Picket Creek drainage divide area

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

Figure 5 illustrates the Sweetwater River-Picket Creek drainage divide area north and east of figure 3 and there is an overlap area with figure 3. The map contour interval for figure 5 is 20 meters. The Sweetwater River flows in an east-northeast direction from the west edge of figure 5 (north half) to the north edge of figure 5 (east half). The Antelope Hills are located south of the Sweetwater River in the northeast quadrant of figure 5. Picket Creek is a south-southeast oriented stream in the southeast quadrant of figure 5. South of figure 5 Picket Creek turns to flow in an east direction to northeast oriented West Alkali Creek, which then flows to north-northwest oriented Alkali Creek, which flows to the northeast oriented Sweetwater River as a barbed tributary (east of figure 5). Buffalo Gulch is a northwest oriented drainage route at the west end of the Antelope Hills draining to the east-northeast oriented Sweetwater River as a barbed tributary. Granite Creek is a north and northeast oriented Sweetwater River tributary located east of Buffalo Gulch. Harris Slough is a northeast and north oriented Sweetwater tributary located west of Buffalo Gulch. St Marys Peak is located slightly north of the east center edge area of figure 5. The Middle Fork Sulphur Creek originates south of St Marys Peak and the North Fork Sulphur Creek originates north of St Marys Peak and they join near the east center edge of figure 5. East of figure 5 Sulphur Creek flows in an east direction to join northeast oriented West Alkali Creek. East of Picket Creek in the southeast quadrant of figure 5 are east-southeast oriented headwaters of South Fork Sulphur Creek (not labeled in figure 5). Study of the Sweetwater River-West Alkali Creek drainage divide reveals shallow northwest to southeast oriented through valleys. For example, south of the Buffalo Gulch headwaters a northwest to southeast oriented through valley links the Sweetwater River valley with the east-southeast oriented South Fork Sulphur Creek valley. The through valley floor elevation is between 2260 and 2280 meters. Elevations greater than 2320 meters can be found on either side of the through valley suggesting the through valley is at least 40 meters deep. While not deep compared to through valleys found in other locations the through valley provides evidence of what was once a southeast oriented flood flow channel crossing the present day Sweetwater River-West Alkali Creek drainage divide. At the time floodwaters flowed in a southeast direction across the present day drainage divide the east-northeast oriented Sweetwater River valley did not exist. Headward erosion of the northeast oriented West Alkali Creek valley south and east of figure 5 first captured the southeast oriented flood flow. Next headward erosion of the east-northeast oriented Sweetwater River valley captured the southeast oriented flood flow and beheaded the flood flow route to the South Fork Sulphur Creek valley. Floodwaters on the northwest end of the beheaded flood flow route reversed flow direction to create the northwest oriented Buffalo Gulch drainage route.

Detailed map of Granite Creek-Middle Fork Sulphur Creek drainage divide area

Figure 6: Detailed map of Granite Creek-Middle Fork Sulphur 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 Granite Creek-Middle Fork Sulphur Creek drainage divide area seen in less detail in figure 5. The map contour interval for figure 6 is 20 feet. The Sweetwater River flows in an east-northeast direction across the northwest corner of figure 6. Buffalo Gulch originates in section 32 and drains in a north, northwest, and north direction to join the Sweetwater River near the northwest corner of figure 6. Granite Creek originates in section 33 and flows in an east-southeast direction into section 34 where it turns to flow in a north direction to the north edge of figure 6 (east of center). North of figure 6 Granite Creek flows in a northeast and then north-northwest direction to join the Sweetwater River. The North Fork Sulphur Creek originates near the northwest corner of section 35 and flows in an east direction to the east center edge of figure 6. The Middle Fork Sulphur Creek originates near the west center edge of section 35 and flows in an east-southeast direction to the east edge of figure 6 (south half). East of figure 6 the North and Middle Forks join to form east oriented Sulphur Creek, which then flows to northeast oriented West Alkali Creek, which flows to north-northwest oriented Alkali Creek, which flows to the northeast oriented Sweetwater River as a barbed tributary. The South Fork Sulphur Creek originates near the south edge of section 34 (south of the north oriented Granite Creek valley) and flows in a southeast and south direction to the south edge of figure 6 (east of center). South of figure 6 the South Fork Sulphur Creek flows in a southeast and then northeast direction to join Sulphur Creek. Through valleys link the Granite Creek valley with the various Sulphur Creek tributary valleys. The easiest to see through valley is located in sections 34 and 35 and links a short northwest oriented Granite Creek tributary valley with the east-oriented Middle Fork Sulphur Creek valley. The through valley floor elevation is between 7480 and 7500 feet. Elevations in the southwest corner of section 35 rise to more than 7540 feet and in the southwest corner of section 26 elevations rise to 7671 feet suggesting the through valley is at least 40 feet deep. South and west of figure 6 elevations rise to at least 7669 feet suggesting the presence of a much broader northwest to southeast oriented through valley that is at least 170 feet deep. The through valleys however they are viewed provide evidence of southeast and/or south oriented flood flow channels that deeply eroded the Antelope Hills region.

Sweetwater River-North Fork Sulphur Creek drainage divide area

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

Figure 7 illustrates the Sweetwater River-North Fork Sulphur Creek drainage divide area east and slightly north of figure 5 and includes an overlap area with figure 5. The map contour interval for figure 7 is 20 meters. The Sweetwater River flows in an east and northeast direction across the northwest corner of figure 7. Labeled Sweetwater River tributaries in the northwest quadrant of figure 7 include north-northeast oriented Mormon Creek, north-northwest oriented Willow Creek, and north-northwest oriented Spring Creek. St Marys Peak is located near the west edge of the southwest quadrant of figure 7 and Horse Track Ridge is located south and east from St Marys Peak. The North Fork Sulphur Creek flows in an east-southeast direction from the Horse Track Ridge area to join northeast oriented South Fork Sulphur Creek (downstream from Sulphur Bar Spring) and to form east oriented Sulphur Creek, which then joins northeast oriented West Alkali Creek. West Alkali Creek makes a jog to the northwest in the east center area of figure 7 before joining northwest oriented East Alkali Creek to form north-northwest oriented Alkali Creek, which north of figure 7 joins the east-northeast oriented Sweetwater River. North Bear Mountain is located near the center of figure 7. Coyote Gulch is an east oriented Alkali Creek tributary located south of North Bear Mountain. Ladysmith Draw is a northeast oriented drainage route north of North Bear Mountain and north of figure 7 drains to the Sweetwater River. The east oriented Coyote Draw valley is linked by through valleys with the northwest oriented Spring Creek valley, northeast oriented Ladysmith Draw valley,  and the north-northwest oriented Willow Creek valley.  A north-northwest to south-southeast oriented through valley links the northwest oriented Willow Creek valley with the northeast oriented Ladysmith Draw valley near Ladysmith Creek and then continues to the east-southeast and south-southeast oriented Coyote Gulch headwaters valley. The through valley floor elevation on both through valley segments is between 2220 and 2240 meters. Elevations east of the through valley rise to 2280 meters and east of figure 7 and the Alkali Creek valley elevations on Crooks Mountain reach 2500 meters. West of the through valley there are isolated regions where elevations exceed 2320 meters and west of figure 7 at Continental Peak and Oregon Buttes elevations exceed 2500 meters. These elevations suggest there are shallow 40-meter deep northwest to southeast oriented through valleys crossing drainage divides in the region seen in figure 7, but that the entire region is the floor of a much broader north to south oriented through valley defined by Crooks Mountain on the east and Oregon Buttes on the west. The north-northwest oriented Alkali Creek drainage route was formed by a reversal of flood flow on the north end of a beheaded south oriented flood flow channel beheaded by headward erosion of the much deeper east-northeast oriented Sweetwater River valley. Headward erosion of the Sweetwater River valley also beheaded and reversed other southeast and south-southeast oriented flood flow channels to create the present day northwest oriented Spring Creek and north-northwest oriented Willow Creek drainage routes.

Detailed map of Sweetwater River-Ladysmith Creek drainage divide area

Figure 8: Detailed map of Sweetwater River-Ladysmith 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 Sweetwater River-Ladysmith Creek drainage divide seen in less detail in figure 7. The map contour interval for figure 8 is 20 feet. The Sweetwater River flows in a southeast and northeast direction from the west edge of figure 8 (north half) to the north edge of figure 8 (west half). Willow Creek flows in a north and north-northwest direction from the south edge of figure 8 (west half) to join the Sweetwater River. The southeast oriented Sweetwater River segment seen near the west edge of figure 8 is a relatively short segment on what is primarily an east-northeast oriented river, but was formed when headward erosion of the deep east-northeast oriented Sweetwater River valley beheaded a southeast or south-southeast oriented flood flow channel on the present day north-northwest oriented Willow Creek alignment. Floodwaters on the north-northwest end of the beheaded flood flow channel reversed flow direction to flow to the much deeper Sweetwater River valley while the southeast oriented flood flow channel eroded a deep valley headward to create the southeast oriented Sweetwater River jog (see figure 7 to see the full jog). Spring Creek originates in section 3 and flows in a northwest direction to join the Sweetwater River as a barbed tributary in section 34. Ladysmith Creek originates in section 10 and flows in an east direction into section 11 where it turns to flow in a northeast and east direction to the east edge of figure 8 (north half). East of figure 8 Ladysmith Creek flows in a northeast and northwest direction to join the east-northeast oriented Sweetwater River. A northwest to southeast oriented through valley in sections 3 and 2 links the northwest oriented Spring Creek valley with the valley of a southeast oriented Ladysmith Creek tributary. The through valley floor elevation is between 7280 feet and 7300 feet. Elevations on the ridge immediately to the northeast of the through valley reach 7429 feet and on the ridge to the southwest of the through valley rise to more than 7500 feet. These elevations suggest the through valley is at least 129 feet deep. Coyote Gulch flows in a southeast and south direction from the northeast corner of section 15 to the south edge of figure 8 (east half-near North Bear Mountain) and south and east of figure 8 flows in an east direction to north-northwest oriented Alkali Creek. Through valleys in sections 12 and 13 link the southeast and south oriented Coyote Gulch valley with the northwest oriented Spring Creek-Ladysmith Creek through valley. Floor elevations of these through valleys are between 7300 and 7320 feet.  Elevations east of the through valleys in section 12 reach 7482 feet and elevations greater than 7500 feet are found west of the through valleys. These elevations suggest the through valleys are approximately 180 feet deep. Numerous similar through valleys can be seen in the region shown by figure 8 and were eroded by south and southeast oriented flood flow channels prior to headward erosion of the much deeper northeast and east-northeast oriented Sweetwater River valley. The northwest and north-northwest oriented and barbed Sweetwater River tributary drainage routes were created by reversals of flood flow on north ends of beheaded flood flow channels to flow in a north direction to the much deeper northeast and east-northeast oriented Sweetwater River valley.

West Alkali Creek-Lost Creek drainage divide area

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

Figure 9 illustrates the West Alkali Creek-Lost Creek drainage divide area east and somewhat south of figure 7 and there is an overlap area with figure 7. The map contour interval for figure 9 is 20 meters. West Alkali Creek flows in a northeast direction from the west center edge of figure 9 to the north edge of figure 9 (west half) and north of figure 9 joins northwest oriented East Alkali Creek to form north-northwest oriented Alkali Creek, which then flows to the east-northeast oriented Sweetwater River. Crooks Mountain is north of northwest oriented East Alkali Creek and west of north-northwest oriented Alkali Creek and is not seen in figure 9. Sulphur Creek flows in an east direction to join northeast oriented West Alkali Creek near the north edge of figure 9. Lost Creek flows in a southwest and south direction from the east edge of figure 9 (south of center) to the south edge of figure 9 (east half-near Big Bend) and south of figure 9 flows in a south direction to Lost Creek Lake where Lost Creek ends. Smiley Springs are located near the center of figure 9. A south and southeast oriented Lost Creek tributary originates at Smiley Springs. Flattop Buttes are located east of Smiley Springs and Cyclone Rim is the “Rim” south and west from Smiley Springs. A northwest to southeast oriented through valley between Flattop Buttes and Cyclone Rim links the northeast oriented West Alkali Creek valley with the south oriented Lost Creek valley. Remember northwest to southeast oriented through valleys seen in earlier figures crossed the Sweetwater River-West Alkali Creek drainage divide. The through valley between Flattop Buttes and Cyclone Rim crosses the West Alkali Creek-Great Divide Basin drainage divide and has a floor elevation of between 2120 and 2140 meters. Elevations on Flattop Buttes exceed 2240 meters, as do elevations on Cyclone Rim. These elevations suggest the through valley is at least 100 meters deep. Another and even deeper northwest to southeast oriented through valley is located north of Flattop Buttes although the north side of the through valley (Crooks Mountain) is not seen in figure 9. These northwest to southeast oriented through valleys were eroded by southeast oriented flood flow channels prior to headward erosion of the West Alkali Creek valley and which occurred prior to headward erosion of the east-northeast oriented Sweetwater River valley (west and north of figure 9). The southeast oriented floodwaters were captured by headward erosion of the south and southwest oriented Lost Creek valley, which eroded headward from the actively eroding Little Snake River (and Yampa River, Green River, and Colorado River) valley. Headward erosion of the deeper northeast oriented West Alkali Creek valley captured the southeast oriented flood flow and diverted floodwaters to the newly reversed flood flow on the north-northwest oriented Alkali Creek alignment, which was flowing to the actively eroding east-northeast oriented Sweetwater River valley head. Continued headward erosion by the Sweetwater River valley head subsequently beheaded flood flow to the newly eroded West Alkali Creek valley and its tributary valleys.

Detailed map of West Alkali Creek-Lost Creek drainage divide area

Figure 10: Detailed map of West Alkali Creek-Lost 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 West Alkali Creek-Lost Creek drainage divide area seen in less detail in figure 9. The map contour interval for figure 10 is 20 feet. Northeast oriented West Alkali Creek is located just west of Daley Lake in the northwest corner of figure 10. The northwest oriented stream flowing from section 2 to the Daley Lake area is a West Alkali Creek tributary. Flattop Buttes is located in sections 33 and 4 near the east edge of figure 10. Cyclone Ridge is the higher area seen near the south edge of figure 10. Smiley Spring is located west of Flattop Buttes in the southeast corner of section 31. A south and southeast oriented stream flows from the Smiley Spring region to the southeast corner of figure 10. South and east of figure 10 the stream flows to south oriented Lost Creek, which then flows to Lost Creek Lake in the Great Divide Basin where the surface drainage ends. A northwest to southeast oriented through valley in section 1 links the northwest oriented West Alkali Creek tributary valley with the southeast oriented Lost Creek tributary valley. The through valley floor elevation is between 7000 and 7020 feet. Elevations on Cyclone Ridge in section 14 reach 7314 feet while high elevations on Flattop Buttes exceed 7360 feet. These elevations suggest the through valley is approximately 300 feet deep. The through valley was eroded by southeast oriented flood flow moving to a south oriented flood flow channel on the present day south oriented Lost Creek alignment. The south oriented floodwaters flowed across the Great Divide Basin to the actively eroding Little Snake River valley and tributary valleys with water then flowing to the Yampa River valley, the Green River valley, the Colorado River valley, and eventually the Pacific Ocean. At that time there was no Sweetwater River valley north of figure 10 and the northeast oriented West Alkali Creek valley did not exist. Headward erosion of the northeast oriented West Alkali Creek valley from north-northwest oriented flood flow reversed by headward erosion of the east-northeast oriented Sweetwater River valley beheaded the southeast oriented flood flow channel to the south oriented Lost Creek valley. Subsequently headward erosion of the east-northeast oriented Sweetwater River valley beheaded southeast oriented flood flow routes to the newly eroded West Alkali Creek valley and tributary valleys.

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.