Abstract:

This essay uses topographic map evidence to interpret landform origins in the Elk River-North Platte River drainage divide in the Colorado Park Range. The Colorado Park Range is a high north to south oriented mountain range on the west side of North Park. North Park is drained by the north oriented North Platte River, which receives significant flow from south and southeast oriented tributaries draining the Park Range eastern slopes, with water eventually reaching the Mississippi River and Gulf of Mexico. The southwest and south oriented Elk River is located west of the Park Range and flows to the north and west oriented Yampa River with water eventually reaching the Colorado River and Pacific Ocean. The south oriented Elk River receives significant flow from north and northwest oriented tributaries draining the Park Range western slopes. High level through valleys cross the present day continental divide and link valleys of North Platte River tributaries with valleys of Elk River tributaries. Other north to south oriented through valleys link valleys of Elk River tributaries or link valleys of North Platte River tributaries. The through valleys, barbed tributaries, elbows of capture, and valley orientations are interpreted in the context of a large-scale complex of diverging and converging flood flow channels that once crossed the region. At the time floodwaters crossed the region the Park Range was just beginning to emerge and at first floodwaters could flow across the emerging mountain range. South oriented floodwaters west of the emerging Park Range at first flowed to a south oriented flood flow channel on the present day north oriented Yampa River alignment (south of Steamboat Springs). Headward erosion of the deeper west oriented Yampa River valley captured the south oriented flood flow channel and floodwaters on the north end of the beheaded flood flow channel reversed flow direction to create the north and west oriented Yampa River drainage route. As the Park Range emerged south oriented floodwaters east of the emerging Park Range were beheaded by headward erosion of a deeper valley in central Wyoming and reversed flow direction to flow in a north direction to create the present day north and southeast oriented North Platte River drainage route. Floodwaters are interpreted to have been derived from the western margin of a thick North American ice sheet and were flowing from western Canada to and across the study region. Ice sheet related crustal warping was responsible for Park Range uplift and uplift of other regional mountain ranges and also for raising the entire North Park region, which contributed greatly to the flood flow reversal on the present day north oriented North Platte River alignment.

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 Elk River-North Platte River drainage divide area landform origins in the Colorado Park Range. 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 Elk River-North Platte River drainage divide area landform evidence in the Colorado Park Range will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Elk River-North Platte River drainage divide area location map

Figure 1: Elk River-North Platte 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 Elk River-North Platte River drainage divide area in the Colorado Park Range and illustrates a region in north central Colorado with Wyoming to the north of Colorado. The Medicine Bow Mountains extend in a north-northwest direction from Rocky Mountain National Park into southern Wyoming. The Park Range is located slightly west of the center of figure 1 and west of the Medicine Bow Mountains and is a north to south oriented mountain range. To the north of the Park Range are the Sierra Madre Mountains and the Gore Range is located south of the Park Range. North Park is the unlabeled intermontane basin located between the Park Range and Medicine Bow Mountains. The North Platte River is formed in North Park at the confluence of tributaries west of Walden, Colorado and then flows in a north and northwest direction to the north center edge of figure 1. North of figure 1 the North Platte River continues in a north direction to flow around the northwest end of the Laramie Mountains (in central Wyoming) and then flows in a southwest direction with water eventually reaching the Gulf of Mexico. The Colorado River originates near the southwest corner of Rocky Mountain National Park and then flows in a west-southwest and southwest direction (with a northwest jog between Bond and McCoy) to the south edge of figure 1 (west half). South and west of figure 1 the Colorado River eventually flows to the Pacific Ocean. The Elk River drains the west slopes of the Park Range and flows in a southwest and south direction to join the north and west oriented Yampa River near Steamboat Springs. The Yampa River flows in a north direction from the town of Yampa to near Steamboat Springs where it turns to flow in a west direction to the west center edge of figure 1. West of figure 1 the Yampa River joins the south oriented Green River, which flows to the southwest oriented Colorado River. The Elk River-North Platte River drainage divide area along the continental divide in the Colorado Park Range investigated in this essay is located along the crest of the north to south oriented Park Range.

Drainage routes throughout the region seen in figure 1 developed during immense melt water floods from the western margin of a thick North American ice sheet. Floodwaters flowed from western Canada in huge complexes of diverging and converging flood flow channels to and across the region seen in figure 1 at a time when the regional mountain ranges were just beginning to emerge. Mountain ranges, including the Park Range, emerged as floodwaters flowed across them and as floodwaters deeply eroded surrounding valleys and basins at the same time as ice sheet related crustal warping raised the mountain ranges and the entire region seen in figure 1. The deep southwest oriented Colorado River valley and its tributary valleys eroded headward into the region to capture the south oriented flood flow and to divert the floodwaters in a southwest direction to the Pacific Ocean. The present day north oriented North Platte River route and the north oriented Laramie River route (east of the Medicine Bow Mountains) originated as a south oriented flood flow channels supplying floodwaters to the actively eroding Colorado River valley and tributary valleys. The present day north oriented Yampa River valley route south of Steamboat Springs and the southwest and south oriented Elk River route to the north of Steamboat Springs also originated as south oriented flood flow channels moving floodwaters across what was at that time the emerging Park Range to actively eroding Colorado River tributary valleys (e.g. see stream flowing from Toponas to join the Colorado River at McCoy). Headward erosion of the west oriented Yampa River valley from the south oriented Green River valley across the south oriented flood flow captured the south oriented flood flow on the Elk River route. Floodwaters on the north end of the beheaded flood flow channel reversed flow direction to create the present day north oriented Yampa River drainage route (located south of Steamboat Springs). Crustal warping that was raising mountain ranges and the entire region greatly assisted in the flood flow reversal process. Similar beheadings of the south oriented flood flow channels on the Laramie River and North Platte River alignments reversed flow along those routes to create the present day north oriented Laramie and North Platte River drainage routes. Flood flow on the Laramie River alignment was beheaded and reversed while south oriented flood flow continued to move on the North Platte River alignment. Reversed flood flow on the Laramie River alignment captured south oriented flood flow on the North Platte River alignment so the captured floodwaters made a large U-turn around the south end of the Medicine Bow Mountains. The reversal of flood flow on the North Platte River alignment ended all flood flow to the North Park region of Colorado.

Detailed location map for Elk River-North Platte River drainage divide area

Figure 2: Detailed location map Elk River-North Platte River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 2 provides a more detailed location map for the Elk River-North Platte River drainage divide area in the Colorado Park Range. Green colored areas are National Forest lands, which in this region are usually located in mountain areas. The east-west continental divide is shown with a labeled dashed line extending from the north center edge of figure 2 to the south center edge of figure 2. The continental divide follows the Park Range crest. Steamboat Springs is located in the southwest quadrant of figure 2. The Yampa River flows in a north direction from the south edge of figure 2 to Steamboat Springs and then turns to flow in a west direction to the west edge of figure 2. West of figure 2 the Yampa River flows to the south oriented Green River with water eventually reaching the Colorado River and Pacific Ocean. Soda Creek is a southwest and south oriented tributary joining the Yampa River at Steamboat Springs. The Elk River originates on the west side of the continental divide near the north edge of figure 2 and flows in a southwest direction to the towns of Glen Eden and Clark and then turns to flow in a south, southeast, and south-southwest direction to join Yampa River west of Steamboat Springs. Labeled Elk River tributaries of interest in this essay include the north, west, and south oriented North Fork; the north-northwest, south, and northwest oriented South Fork, and west-northwest and south-southwest oriented Big Creek. West and southwest oriented Mad Creek is not labeled, but joins the Elk River at the town of Mad Creek. The North Fork North Platte River flows in a south direction from the north edge of figure 2 (just east of the green colored area) and north of Delaney Butte turns in a northeast and then southeast direction to join the Roaring Fork North Platte River and to form the north oriented North Platte River, which flows to the north edge of figure 2 (east half-north of town of Cowdrey). North of figure 2 the North Platte River flows in a north-northwest and north direction into central Wyoming where it flows the around the northwest end of the Laramie Mountains and then flows in southeast direction to Nebraska with water eventually reaching the Gulf of Mexico. Lake Creek is a south oriented North Fork North Platte River tributary and Lone Pine Creek is an east-southeast and east oriented tributary, while east oriented Hell Creek joins the North Fork just before the North Fork joins the Roaring Fork. The Roaring Fork North Platte River flows in a northeast, southeast, east, and northeast direction from near the continental divide to join the North Fork and to form the north oriented North Platte River. Beaver Creek is a southeast and northeast oriented Roaring Fork tributary. South of Beaver Creek is east oriented Chedsey Creek, which flows to north, east, northeast, southeast, northeast, and northwest oriented Little Grizzly Creek, with Little Grizzly Creek joining the Roaring Fork south of Delaney Butte. While most drainage routes west of the continental divide are oriented in south directions the Yampa River south of Steamboat Springs, the unlabeled stream joining the west oriented Yampa River near Milner, and headwaters of some Elk River tributaries flow in north directions. These north oriented drainage routes were formed by reversals of flood flow on north ends of beheaded south oriented flood flow channels. East of the continental most streams have been reversed and are now oriented in a north direction although many streams have southeast oriented headwaters or segments, which in addition the south oriented North Fork North Platte River and Lake Creek drainage routes are relics of the south oriented flood flow channels that once crossed the region.

North Fork Elk River-North Fork North Platte River drainage divide area

Figure 3: North Fork Elk River-North Fork North Platte River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 3 provides a topographic map of North Fork Elk River-North Fork North Platte River drainage divide area. The map contour interval for figure 3 is 50 meters. The east-west continental divide serves as the Routt-Jackson County line and is shown as a dashed line extending from the north edge of figure 3 (slightly west of center) to the south center edge of figure 3. The North Fork North Platte River flows in a south direction from the north edge of figure 3 (east half) to the east edge of figure 3 (near southeast corner) and east and south of figure 3 turns in a northeast and then southeast direction to join the Roaring Fork and to form the north and north-northwest oriented North Platte River with water eventually reaching the Gulf of Mexico. Bighorn Lake is located just east of the continental divide and near the south edge of figure 3. Lone Pine Creek flows in an east-southeast, east, and southeast direction from Bighorn Lake to the south edge of figure 3 (near southeast corner) and south and east of figure 3 joins the North Fork North Platte River. Mount Zirkel is located on the continental divide slightly north of the center of figure 3. Shafer Creek originates in the Fryingpan Basin (east of Mount Zirkel) and flows in a northeast and east direction to join the south oriented North Fork North Platte River. The North Fork Elk River originates west of Mount Zirkel and flows in a north, west, southwest, and south direction to join the west-southwest oriented Middle Fork Elk River near the southwest corner of figure 3 and to form the southwest and south oriented Elk River, which flows to the west oriented Yampa River with water eventually reaching the Colorado River and Pacific Ocean. The Middle Fork Elk River is formed near Slavonia at the confluence of south and southwest oriented Gilpin Creek and south, southwest and west oriented Gold Creek. Today the Shafer Creek-Gold Creek drainage divide is a high mountain ridge, which also serves as the east-west continental divide. Yet a close look at that ridge reveals a notch, pass, or through valley linking the north oriented Shafer Creek headwaters valley with the south oriented Gold Creek valley. The pass elevation is between 3500 and 3550 meters. Elevations to the south rise to at least 3700 meters and Mount Zirkel to the north rises to more than 3700 meters. These elevations suggest the pass is at least 150 meters deep. A similar pass links the north oriented North Fork Elk River headwaters valley with the south oriented Gilpin Creek headwaters valley and has a floor elevation of between 3350 and 3400 meters. Big Agnes Mountain to the west rises to more than 3650 meters suggesting the pass is at least 250 meters deep. These passes and other similar passes crossing the Park Rang high mountain ridges were eroded by diverging and converging flood flow channels into an erosion surface now preserved, if it is preserved at all, by the tops of the high mountains seen in figure 3. Since that time the Park Range has been uplifted and floodwaters have eroded deep valleys on either side of the mountain range and also have eroded deep valleys headward into the emerging mountain range.

Detailed map of Shafer Creek-Gold Creek drainage divide area

Figure 4: Detailed map of Shafer Creek-Gold 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 Shafer Creek-Gold Creek drainage divide area seen in less detail in figure 3. The map contour interval for figure 4 is 40 feet. The east-west continental divide is shown with a labeled dashed line extending from the north edge of figure 4 (west of center) along the Park Range crest to the south edge of figure 4 (west of center). Mount Zirkel is located on the continental divide near the north edge of figure 4. Shafer Creek originates east of Mount Zirkel and flows in a northeast direction to the north center edge of figure 4. North and east of figure 4 Shafer Creek flows in a northeast and east direction to join the south oriented North Fork North Platte River, which flows to the north oriented North Platte River as a barbed tributary. The basin in which Shafer Creek originates is a large northeast-facing cirque that was eroded at the head of a valley glacier. The valley glacier filled a pre-existing valley and while the valley shape and depth were probably altered the valley orientation probably was not changed. Red Dirt Pass is on the south side of the cirque and links the northeast oriented Shafer Creek valley with the south oriented Gold Creek valley. Gold Creek flows in a south and southwest direction to the south edge of figure 4 (west half) and south and west of figure 4 joins Gilpin Creek to form the southwest oriented Middle Fork Elk River, which flows to the southwest and south oriented Elk River with water eventually reaching the Colorado River and Pacific Ocean. Red Dirt Pass has an elevation of between 11,520 and 11,560 feet. Mount Zirkel rises to 12,180 feet and Flattop Mountain rises to 12,118 feet suggesting the Red Dirt Pass is at least 500 feet deep. The north oriented stream in PB 41 west of Mount Zirkel is the headwaters of the North Fork Elk River, which north of figure 4 turns to flow in a west, southwest, and south direction to join the Middle Fork and to form the southwest and south oriented Elk River. The south and southwest oriented stream in PB 45 is Gilpin Creek, which flows to the west edge of figure 4 and which west of figure 4 joins Gold Creek to form the Middle Fork Elk River. An unnamed pass west of Mount Zirkel in PB 44 links the north oriented North Fork Elk River headwaters valley with the south oriented Gilpin Creek headwaters valley. The pass elevation is between 11,040 and 11,080 feet. Big Agnes Mountain to the west rises to 12,059 feet suggesting the pass is approximately 1000 feet deep. A case can be made for glaciation of all valleys seen in figure 4. However, as previously stated the glaciers filled and eroded pre-existing valleys and did not erode new valleys or significantly change valley orientations. Big picture evidence suggests the passes are remnants of pre-existing diverging and converging valleys that once crosses the region. Such a pattern of valleys describes a flood formed anastomosing channel complex and is consistent with the big picture evidence.

South Fork Elk River-Roaring Fork North Platte River drainage divide area

Figure 5: South Fork Elk River-Roaring Fork North Platte River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 5 illustrates the South Fork Elk River-Roaring Fork North Platte River drainage divide area south of figure 3 and there is an overlap area with figure 3. The map contour interval for figure 5 is 50 meters. The east-west continental divide serves as the county line and is shown with a labeled dashed line extending from the north edge of figure 5 (east of center) to the south center edge of figure 5. The North Fork North Platte River flows in a south and south-southeast direction across the northeast corner of figure 5 and east of figure 5 turns to flow in a northeast and southeast direction to join the Roaring Fork and to form the north oriented North Platte River with water eventually reaching the Gulf of Mexico. Bighorn Lake is located on the east side of the continental divide near the center of figure 5. Lone Pine Creek flows in an east-southeast direction from Bighorn Lake to the east center edge of figure 5 and east of figure 5 joins the North Fork North Platte River. A Roaring Fork tributary flows from the lake straddling the south edge of figure 5 (east of continental divide in a northeast direction to join east-southeast oriented Roaring Fork, which then flows in southeast and east-southeast direction to the east edge of figure 5. East of figure 5 Roaring Fork flows in an east and northeast direction to join the North Fork and to form the north oriented North Platte River. In the northwest quadrant of figure 5 south and southwest oriented Gold Creek and southwest oriented Gilpin Creek join near Slavonia to form the west-southwest oriented Middle Fork Elk River, which joins the south oriented North Fork Elk River to form the southwest oriented Elk River (“River” in figure 5) and which flows to the west center edge of figure 5. The Dome is a mountain located slightly west of the continental divide and near the south edge of figure 5. Dome Lake is north of the Dome. The South Fork Elk River originates at Dome Lake and flows in north-northwest, south-southwest, and northwest direction to join the southwest oriented Elk River just west of the west center edge of figure 5. Note how a deep north to south oriented through valley links the south oriented North Fork Elk River valley with the north-northwest and south-southwest oriented South Fork Elk River valley. The through valley is approximately 250 meters deep and was eroded by south oriented flood flow prior to headward erosion of the deeper southwest oriented Elk River valley. A subtle, but even more intriguing through valley links the east-southeast oriented Roaring Fork valley with the north-northwest oriented South Fork Elk Creek valley. The through valley where it crosses the continental divide has an elevation of between 3250 and 3300 meters. Lost Ranger Peak to the south rises to more than 3600 meters and continental divide elevations near the north edge of figure 5 rise to more than 3600 meters. These elevations suggest a broad west to east oriented 300-meter deep through valley crosses the continental divide. The through valley may have been initiated by floodwaters flowing from the south oriented flood flow channels west of the Park Range to the south oriented flood flow channels east of the emerging Park Range. However, it is also possible after the reversal of flood flow on the North Platte River alignment south oriented floodwaters from west of the emerging Park Range flowed to the newly formed north oriented North Platte River drainage route east of the emerging Park Range. In either case headward erosion of the deeper southwest oriented Elk River valley and it tributary valleys captured the flood flow moving eastward across the present day continental divide.

Detailed map of South Fork Elk River-Roaring Fork North Platte River drainage divide area

Figure 6: Detailed map of South Fork Elk River-Roaring Fork North Platte River 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 South Fork Elk River-Roaring Fork North Platte River drainage divide area seen in less detail in figure 5. The map contour interval for figure 6 is 40 feet. The east-west continental divide serves as the county line and is shown with a dashed line extending from the north edge of figure 6 (east of center) along the Park Range crest to the south center edge of figure 6. The South Fork Elk River flows in a north-northwest direction from the south edge of figure 6 (west half) to near the northwest corner of figure 6. North and west of figure 6 the South Fork turns to flow in a south-southwest and northwest direction to join the southwest and south oriented Elk River with water eventually reaching the Colorado River and Pacific Ocean. The Roaring Fork North Platte River originates in the southeast corner of section PB 46 and flows in an east-southeast direction to the east edge of figure 6 (slightly south of center). East of figure 6 Roaring Fork flows in a southeast, east, and northeast direction to join the North Fork North Platte River and to form the north oriented North Platte River with water eventually reaching the Mississippi River and the Gulf of Mexico. A west to east oriented through valley centered on section PB 47 crosses the continental divide and links the east and southeast oriented Roaring Fork valley with the north-northwest oriented South Fork Elk River valley. The through valley floor elevation is shown as 10,750 feet. Lost Ranger Peak (located just south of the south edge of figure 6) rises to 11,932 feet. The south end of Flattop Mountain to the north of figure 6 (and seen in figure 4) rises to 12,118 feet. These elevations suggest the broad west to east oriented through valley seen in figure 6 is almost 1200 feet deep. This through valley was probably eroded by southeast oriented flood flow moving from the present day north-northwest oriented South Fork Elk River alignment to the east-southeast and southeast oriented Roaring Fork valley. Remember from figure 5 the north-northwest oriented South Fork Elk River alignment is just south of the south oriented North Fork Elk River valley. While not seen in this essay the south oriented North Fork valley is linked by deep through valleys (across the continental divide) with north oriented headwaters and tributary valleys draining to the north oriented Encampment River (see Encampment River-Elk River drainage divide area landform origins essay). The present day north-northwest oriented South Fork Elk River drainage direction was created by a reversal of flood flow when headward erosion of the much deep southwest oriented Elk River valley captured the south oriented flood flow and beheaded the flood flow channel. The region seen in figure 6 has been glaciated and the South Fork Elk River valley has probably been deepened and otherwise altered by glacial erosion. While ice may have once covered the west to east oriented through valley crossing the continental divide it is  difficult to argue the through valley was eroded by glacial erosion.

Big Creek-Beaver Creek drainage divide area

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

Figure 7 illustrates the Big Creek-Beaver Creek drainage divide area south of figure 5 and includes an overlap area with figure 5. The map contour interval for figure 7 is 50 meters. The east-west continental divide serves as the county line and is shown with a labeled dashed line extending from the north edge of figure 7 (east of center) to the south center edge of figure 7. Big Creek is located in the northwest quadrant of figure 7 and originates near the continental divide before flowing in a west-northwest and west-southwest direction to the west edge of figure 7 (near northwest corner). West of figure 7 Big Creek turns to flow in a south-southwest direction to join the south oriented Elk River with water eventually reaching the Colorado River and Pacific Ocean. Mad Creek flows in a south-southwest direction to the west edge of figure 7 (south center) and west of figure 7 also flows to the south oriented Elk River. Mad Creek tributaries include its west and west-northwest oriented North, Middle, and South Forks. Many drainage routes east of the continental divide originate as southeast oriented streams and then turn to flow in northeast directions to reach the north oriented North Platte River with water eventually reaching the Gulf of Mexico. For example near the north edge of figure 7 Raspberry Creek flows in a southeast, east, southeast, and northeast direction to the east edge of figure 7. Further south Beaver Creek flows in a southeast and northeast direction to the east center edge of figure 7. Still further south and near the south edge of figure 7 Newcomb Creek flows in a southeast, northeast, and southeast direction to join east-southeast and east-northeast oriented Chedsey Creek. This southeast orientation of the east oriented streams is evidence the valleys were eroded by southeast oriented flood flow channels moving floodwaters to south oriented flood flow channels east of the emerging Park Range. The U-turns made by these streams to flow in a northeast direction is evidence the south oriented flood flow channels east of the emerging Park Range were reversed to flow in a north direction and captured the southeast oriented flood flow. The west-northwest oriented Big Creek, North Fork Mad Creek, Middle Fork Mad Creek, and South Fork Mad Creek headwaters valleys probably were formed by reversals of southeast oriented flood flow channels crossing the emerging Park Range. The flood flow reversals occurred as the southeast oriented flood flow channels were systematically beheaded by headward erosion of the much deeper south-southwest oriented Mad Creek and Big Creek valleys. Park Range uplift, which was occurring as floodwaters flowed across it, probably contributed significantly to the flood flow reversals.

Detailed map of Big Creek-Middle Fork Mad Creek drainage divide area

Figure 8: Detailed map of Big Creek-Middle Fork Mad 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 Big Creek-Middle Fork Mad Creek drainage divide seen in less detail in figure 7. The map contour interval for figure 8 is 40 feet. The east-west continental divide is the county line and is shown with a labeled dashed line extending from the north center edge of figure 8 to the south edge of figure 8 (west of center). Big Creek is located in the northwest quadrant of figure 8 and flows in a north-northwest, southwest, northwest, and west direction from near the continental divide to the west edge of figure 8 (near northwest corner). West of figure 8 Big Creek turns to flow in a south-southwest direction to join the south oriented Elk River with water eventually reaching the Colorado River and Pacific Ocean. Luna Lake is located in the southwest quadrant of figure 8 and the Middle Fork Mad Creek flows in a west direction from Luna Lake to the west edge of figure 8. West of figure 8 the Middle Fork flows in a northwest direction to northwest, west, and south-southwest oriented North Fork Mad Creek, which flows to south-southwest oriented Mad Creek with water then flowing to the south oriented Elk River. Lake Elbert is located south of Luna Lake and the South Fork Mad Creek flows in a southwest, west, northwest, and southwest direction from Lake Elbert to the west edge of figure 8 (near southwest corner). South and west of figure 8 the South Fork flows in a south and west direction to join south-southwest oriented Mad Creek. Looking at the east side of the continental divide Beaver Creek originates in section 26 and flows in an east and southeast direction to the southeast corner of figure 8. East of figure 8 Beaver Creek flows in a southeast and northeast direction to join the Roaring Fork with water eventually reaching the North Platte River and the Gulf of Mexico. Norris Creek originates in the southeast corner of section 14 and flows in a southeast and east direction to Rainbow Lake and east of figure 8 flows in a northeast direction to join Raspberry Creek with water eventually reaching the north oriented North Platte River. Roxy Ann Lake in the northeast quadrant of figure 8 is drained by northeast oriented Red Canyon, which north of figure 8 drains to southeast oriented Roaring Fork. Valleys on opposite sides of the continental divide are linked by high level through valleys or passes crossing the continental divide. For example in the northwest corner of section 14 a through valley or pass links the Big Creek valley with the Red Canyon valley. The through valley floor elevation is between 11,360 and 11,400 feet. Mount Ethel to the south rises to 11,924 feet and Lost Ranger Peak (north of figure 8) rises to 11,932 feet. These elevations suggest the through valley is more than 500 feet deep. Perhaps easier to see are north to south oriented through valleys west of Mount Ethel linking the Big Creek valley with the Middle Fork Mad Creek valley and with the South Fork Mad Creek valley. The through valley near the west edge of section 22 has a floor elevation of between 10,920 and 10,960 feet. Elevations to the west rise to 11,577 feet suggesting the through valley more than 500 feet deep. Further west is the through valley used by the Big Creek Lake Trail, which has a floor elevation of between 10,720 and 10,760 feet. Elevations in section PB 43 rise to 11,081 feet suggesting the through valley is more than 300 feet deep. Again the region has been glaciated and the glaciers have deepened and otherwise modified some of the valleys. However the glaciers filled pre-existing valleys and probably did not erode new valleys or change valley orientations. If correctly interpreted the through valleys existed in some form prior to the glaciation and were eroded by flood flow channels into an erosion surface now preserved, if it is preserved at all, by the highest Park Range elevations. At first floodwaters flowed in a southeast and east direction across the present day continental divide to south oriented flood flow channels east of the emerging Park Range. Reversal of those flood flow channels captured the southeast oriented flood flow and diverted the floodwaters north on the North Platte River alignment. Next Park Range emergence caused floodwaters to flow in a south direction along the west side of the emerging Park Range crest ridge and deep south-southwest oriented valleys and their tributary valleys eroded headward to capture the south oriented flood flow.

South Fork Mad Creek-Soda Creek drainage divide area

Figure 9: South Fork Mad Creek-Soda Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Figure 9 illustrates the South Fork Mad Creek-Soda Creek drainage divide area south and west of figure 7 and there is an overlap area with figure 7. The map contour interval for figure 9 is 50 meters. The east-west continental divide is shown with a labeled dashed line extending from the north edge of figure 9 (east half) to near the southeast corner of figure 9. Steamboat Springs is the town located along the south edge of the southwest quadrant of figure 9. The Yampa River flows in a west direction from Steamboat Springs to the west edge of figure 9 (near southwest corner) and west of figure 9 eventually reaches the south oriented Green River with water subsequently reaching the Colorado River and Pacific Ocean. The Elk River flows in a south-southeast direction from the west edge of figure 9 (north half) to the town of Mad Creek and then turns to flow in a southwest direction to the west edge of figure 9 (south of center) and west of figure 9 joins the Yampa River. A through valley used by the highway between Mad Creek and Steamboat Springs links the south-southeast oriented Elk River valley segment with a north oriented Yampa River valley segment (south of Steamboat Springs). The through valley is defined by three contour lines on the west side suggesting it is at least 100 meters deep. The through valley was eroded by south oriented flood flow moving to a south oriented flood flow channel on the present day north oriented Yampa River alignment (south of figure 9) and then to south oriented Colorado River tributary valleys. A diverging southwest oriented flood flow channel on the present day Elk River alignment moved floodwaters to other south oriented flood flow channels further to the west. Mad Creek flows in a south-southwest direction from the north edge of figure 9 (west of center) to join the Elk River near the town of Mad Creek. The South Fork Mad Creek flows in a south direction from the north edge of figure 9 (east of center) and then in a west direction across the north center area of figure 9. The East Branch South Fork Mad Creek originates near the continental divide and flows in a west and northwest direction to join the south and west oriented South Fork Mad Creek. Soda Creek originates near the continental divide and south of the East Branch South Fork Mad Creek headwaters and flows in a southwest and south direction to join the north and west oriented Yampa River at Steamboat Springs. A north to south oriented through valley links a northwest oriented East Branch tributary valley with the southwest oriented Soda Creek headwaters valley. The through valley was eroded by south oriented flood flow moving to the southwest and south oriented Soda Creek valley prior to headward erosion of the deeper East Branch valley. Buffalo Pass is located on the continental divide south of the Soda Creek headwaters and links a north-northeast oriented Chedsey Creek tributary valley with the southwest oriented North Fork Fish Creek valley with Fish Creek being a southwest oriented stream flowing to the north oriented Yampa River (south of figure 9) as a barbed tributary. Unlike passes crossing the continental divide further to the north Buffalo Pass was probably eroded by southwest oriented flood flow moving from east of the emerging Park Range to a south oriented flood flow channel on the present day north oriented Yampa River alignment (south of figure 9). Flood flow across Buffalo Pass ended as the Park Range emerged and as flood flow directions east of the emerging Park Range were beheaded and reversed.

Detailed map of South Fork Mad Creek-Soda Creek drainage divide area

Figure 10: Detailed map of South Fork Mad Creek-Soda 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 South Fork Mad Creek-Soda Creek drainage divide area seen in less detail in figure 9. The map contour interval for figure 10 is 40 feet. The east-west continental divide is shown with a labeled dashed line extending from the north center edge of figure 10 to the south edge of figure 10 (east of center). Buffalo Pass is located on the continental divide near the south edge of figure 10. The south-southwest oriented stream flowing from near Buffalo Pass to the south center edge of figure 10 is the headwaters of southwest oriented North Fork Fish Creek, which flows to southwest oriented Fish Creek with Fish Creek flowing to the north and west oriented Yampa River as a barbed tributary. Summit Lake on the east side of Buffalo Pass drains to a north-northeast oriented Chedsey Creek tributary. Chedsey Creek originates in the northeast quadrant of figure 10 and flows in an east direction south of Round Mountain before turning in a south-southeast direction to flow to the east edge of figure 10 (north of center). East of figure 10 Chedsey Creek flows to north oriented Little Grizzly Creek with water eventually reaching the North Platte River and Gulf of Mexico. The Buffalo Pass elevation is 10,300 feet. Just south of figure 10 elevations along the continental divide rise to 10,568 feet suggesting the Buffalo Pass depth is at least 268 feet. Buffalo Pass was eroded by southwest oriented flood flow moving from east of the emerging Park Range to a south oriented flood flow channel on the present day north oriented Yampa River headwaters alignment and then to an actively eroding south oriented Colorado River tributary valley. Soda Creek originates in section 22 and flows in a south, west, and southwest direction to the west edge of figure 10 (south half) and south and west of figure 10 flows in a southwest and south direction to join the north and west oriented Yampa River at Steamboat Springs. A southwest and south oriented tributary flows across section 15 and joins Soda Creek in the north half of section 21. The west-northwest and north oriented stream north of that Soda Creek tributary flows to the northwest oriented East Branch South Fork Mad Creek segment north of figure 10, which then flows to the west oriented South Fork Mad Creek with water then flowing to south-southwest oriented Mad Creek and the south oriented Elk River (which flows to the west oriented Yampa River). A through valley in the north half of section 16 links the East Branch tributary valley with the south oriented Soda Creek tributary valley. The through valley floor elevation is between 10,400 and 10,440 feet. West of the through valley elevations rise to 10,945 feet and east of the through valley elevations along the continental divide near the north edge of figure 10 exceed 11,000 feet. These elevations suggest the through is more than 500 feet deep. The through valley is evidence of a south oriented flood flow channels west of the emerging Park Range crest, which was beheaded by headward erosion of the deeper south-southwest oriented Mad Creek valley and its west oriented South Fork Mad Creek valley. The northwest oriented East Branch South Fork Mad Creek and tributary drainage route was created by a reversal of flood flow on the north end of the beheaded south and southeast oriented flood flow channel.

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.