Abstract: Multiple deep passes crossing the present-day east-west continental divide and numerous south-oriented tributaries flowing to the present-day north-oriented Gallatin, Madison, Jefferson-Beaverhead-Red Rock, and Missouri Rivers provide evidence the Gallatin, Madison, and Jefferson-Beaverhead-Red Rock valleys originated as diverging channels in a large-scale south-oriented anastomosing channel complex that was subsequently reversed to form the present-day north-oriented Gallatin, Madison, and Jefferson-Beaverhead-Red Rock River drainage routes. Melt water from a continental ice sheet is the most probable source for the immense quantities of water required to form and maintain the south-oriented anastomosing channel complex, although commonly accepted Tertiary history models do not recognize a continental ice sheet’s existence at the time the anastomosing channel complex would have been active. Emergence of mountain ranges forming the present-day east-west continental divide dismembered the south-oriented anastomosing river channels and caused massive reversals of flow that created the present-day north-oriented Red Rock, Beaverhead, Jefferson, Madison, Gallatin, and Missouri Rivers.

Introduction: Since the publication of Todd’s 1914 paper in Science the present day north-oriented Missouri, Jefferson, Madison, and Gallatin River drainage basins in Montana have been considered by most geologists to have formed during Tertiary (pre-ice age) time and the hypothesis has been a building block used directly or indirectly in most Cenozoic history interpretations. For example, Sears in a 2013 GSA Today article proposes that a late Oligocene-early Miocene River flowed in a north direction through the Montana Missouri River valley from the Grand Canyon area to the Labrador Sea. Clausen (2014) in a comment about the Sears hypothesis suggested Montana erosional landform evidence could be better explained by the reversal of large south-oriented melt water floods flowing from a decaying North American ice sheet. Sears (2014) in his response to the Clausen comment cited Oligocene and Miocene vertebrate fossil and radiometric age data as evidence that falsified Clausen’s hypothesis of south-flowing melt water floods. The purpose of this essay is to briefly present examples of erosional landform evidence supporting Clausen’s hypothesis.

Deep passes eroded across present day mountain ranges: Today deep passes in the Henrys Lake area (just west of Yellowstone National Park) link the north-oriented Jefferson-Beaverhead-Red Rock, Madison, and Gallatin River drainage basins with south-oriented Snake River tributaries. Red Rock Pass links the south-oriented Henrys Fork (of the Snake River) with the present day west-oriented Red Rock River valley, which drains to the present day north-oriented Jefferson-Beaverhead River valley. Raynolds Pass, Targee Pass, and Reas Pass, among others, link the south-oriented Henrys Fork valley with the north-oriented Madison River valley and indirectly by additional passes with the north-oriented Gallatin River valley. West of the Centennial Mountains additional deep passes, including Monida Pass, Deadman Pass, and Bannock Pass link south-oriented streams flowing towards the Snake River with the north-oriented Jefferson-Beaverhead River valley. The deep passes mentioned are hundreds of meters deep and cross the present-day east-west continental divide. Each pass required immense quantities of water to erode and was eroded as mountain ranges forming the continental divide were uplifted and surrounding regions subsided and/or were deeply eroded. Today Red Rock Pass, Raynolds Pass, Targee Pass, and Reas Pass are at the heads of diverging valleys that converge at Three Forks to form the present-day north-oriented Missouri River. This evidence for diverging and converging valleys can be interpreted in one of two ways.

 

Figure 1: Map of the Missouri River headwaters area.  The south-oriented Henrys Fork (of the Snake River) valley is linked by deep passes in the Henrys Lake area with north oriented Missouri River tributaries. 1. (near southwest corner) Red Rock Pass links the Henrys Fork valley with the west and northwest oriented Red Rock River, which joins the northeast oriented Beaverhead-Jefferson River. 2. (north of Henrys Lake) Raynolds Pass links the south-oriented Henrys Fork valley with the north oriented Madison River valley. 3. (east of Henrys Lake) Targee Pass links the Henrys Fork valley with the Madison River valley and with passes linking the Madison River valley with the Gallatin River valley. 4. (near southeast corner) Reas Pass links the Henrys Fork valley with the Madison River valley and with passes linking the Madison River valley with the Gallatin River valley. United States Geological Survey map digitally presented using National Geographic Society TOPO software (click on maps to obtain an enlarged image). 

The first interpretation is the present day Red Rock Pass, Raynolds Pass, Targee Pass, and Reas Pass valleys were eroded by north oriented channels that diverged from a north-flowing river in the present day Henry’s Fork valley, which suggests a north-oriented anastomosing channel complex. In other words north-oriented channels diverged before crossing the present day east-west continental divide and then converged again at Three Forks. This north-oriented anastomosing channel complex would have required immense volumes of water to create and maintain, especially as deep valleys were being eroded into the emerging mountain masses. A southwest United States water source capable of creating and maintaining such a north-oriented anastomosing channel complex has never been described. Further, the channel that would have eroded Red Rock Pass is difficult to explain in the context of a north-oriented anastomosing channel complex diverging from the Henrys Fork valley.

The second interpretation is the diverging and converging valley complex originated as a south-oriented anastomosing channel complex, which was formed and maintained by immense south-oriented melt water floods from a melting continental ice sheet. Anyone familiar with commonly accepted Cenozoic history interpretations will immediately object to the south-oriented anastomosing channel complex hypothesis as Sears (2014) did by saying that at the time the mountains were emerging no continental ice sheet existed. The problem, however, is not with finding a water source, but with finding a water source that existed at the time the mountain ranges forming the present-day east-west continental divide were emerging and unlike the north-oriented anastomosing channel complex problem is not a problem of lack of evidence, but is a problem of how observed continental ice sheet and mountain emergence evidence is interpreted.

Barbed tributaries joining the north-oriented Red Rock River: The Red Rock River originates in the Centennial Valley and first flows in a west direction before turning in a northwest and north-northwest direction to join the north and northeast oriented Beaverhead River, which then joins the Big Hole River to become the Jefferson River. Several south-oriented streams flow from the north to join the west oriented Red Rock River (not illustrated here), but perhaps much more significant is Sage Creek (figure 2), which originates in the Blacktail Mountains and then flows in a southeast and south direction before making a U-turn to join the north-northwest oriented Red Rock River. The Sage Creek U-turn is excellent evidence that a reversal of flow in the Red Rock River valley has captured a south oriented drainage system.

Figure 2: South-oriented Sage Creek joins the north-oriented Red Rock River. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Barbed tributaries joining the Beaverhead River: Continuing north along the Red Rock River at Clark Canyon Reservoir east-southeast oriented Horse Prairie Creek joins the Red Rock River to form the northeast oriented Beaverhead River. Horse Prairie Creek headwaters flow in a north direction from the Bannock and Deadman Pass area, although numerous south and southeast-oriented tributaries flow to the east and east-southeast oriented Horse Prairie Creek valley segment. Of special significance is Bloody Dick Creek, which flows in a south-southeast direction from a 500-meter deep pass drained on the north by north-oriented Big Hole River headwaters. The deep pass and Bloody Dick Creek orientation suggest water once flowed in a south direction from the Big Hole Basin to the Bannock Pass area and then into the present-day Snake River drainage basin before being captured by a Beaverhead River valley reversal of flow.

Further to the north Grasshopper Creek flows in a south, southeast, and east direction from another 500-meter deep pass across the Pioneer Mountains to join the northeast oriented Beaverhead River (figure 3). The north-oriented Wise River drains the north side of the deep pass and flows to the southeast, south, and northeast oriented Big Hole River. Again the deep pass is evidence of a major river that once flowed across the present-day Pioneer Mountains and is easiest to explain in the context of a giant south-oriented anastomosing channel complex.

Figure 3: South, southeast, and east oriented Grasshopper Creek flows from a deep pass eroded across the Pioneer Mountains (north of the northwest corner of figure 3) to join the northeast-oriented Beaverhead River (seen in southeast corner of figure 3). United States Geological Survey map digitally presented using National Geographic Society TOPO software.

East and north of Grasshopper Creek is Rattlesnake Creek (see figure 4), which also begins in the Pioneer Mountains (north of the northwest corner of figure 4) and which flows in a south and then southeast and east direction to join the northeast-oriented Beaverhead River near Dillon, Montana.

Figure 4: South and southeast oriented Rattlesnake Creek flows from the Pioneer Mountains (north of figure 4 northwest quadrant) to join the northeast-oriented Beaverhead River near Dillon, Montana. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Barbed tributaries joining the Jefferson River: Still further to the north the Beaverhead River is joined by the Big Hole River to form the northeast-oriented Jefferson River. The Big Hole River originates as a north-oriented river on the north side of a deep pass drained by southeast oriented Bloody Dick Creek, which flows to the east-southeast oriented Horse Prairies Creek segment and then to the northeast-oriented Beaverhead River as described above. After flowing in a north direction across the Big Hole Basin (west of the Pioneer Mountains) the Big Hole River flows north of the Pioneer Mountains as it turns to flow in a southeast and then south direction before making a giant U-turn to join the northeast oriented Beaverhead River and to form the northeast oriented Jefferson River (figure 5).

Figure 5: South oriented Big Hole River makes a large U-turn to join the northeast-oriented Beaverhead River and to form the northeast-oriented Jefferson River. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

The northeast-oriented Jefferson River segment has several significant southeast-oriented tributaries such as Hells Canyon Creek seen in figure 6.

Figure 6: Southeast oriented Hells Canyon Creek and other streams flow in a southeast direction to join the northeast-oriented Jefferson River. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Continuing downstream (or north) the present day northeast-oriented Jefferson River is joined by south-oriented Whitetail Creek and then by the south-oriented Boulder River (figure 7) before turning in a southeast and east direction to join the Madison and Gallatin Rivers at Three Forks, Montana to form the north-oriented Missouri River.

Figure 7: Jefferson River flows in a northeast and southeast direction in the south center area of figure 7 and is first joined by south-oriented Whitetail Creek and then by the south-oriented Boulder River. The Boulder River originates on the north side of a deep pass across the east-west continental divide (the south side of the pass is drained by Silver Bow Creek, which flows to the Clark Fork River) and flows in a north direction west of figure 7 before making a U-turn to flow in a south direction as seen in figure 7. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Barbed tributaries joining the north-oriented Missouri River: North of Three Forks, Montana the north-oriented Missouri River is joined by several significant south-oriented tributaries. One of the more interesting barbed tributaries is Crow Creek, which makes a U-turn to join the north-oriented Missouri River (figure 8).

Figure 8: South oriented Crow Creek flows  in a south direction before making a U-turn to join the north-oriented Missouri River. The Boulder River can be seen flowing a southeast direction in the southwest corner of figure 8. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Northeast-oriented tributaries to the north-oriented Missouri River also have southeast-oriented tributaries. Figure 9 illustrates how northeast-oriented Little Prickly Pear Creek is joined by southeast-oriented Lyons Creek and southeast-oriented Wolf Creek before it joins the north-oriented Missouri River and also shows southeast-oriented Wolf and Dog Creeks as they join the Missouri River as barbed tributaries.

Figure 9: North-northeast oriented Little Prickly Pear Creek joins the north-northwest and north-northeast oriented Missouri River in the east center area of figure 9. Wolf Creek flows in a southeast direction to join Little Prickly Pear Creek as a barbed tributary near the town of Wolf Creek. Lyons Creek is the southeast-oriented Little Prickly Pear Creek barbed tributary west of Wolf Creek. Rock Creek is the southeast-oriented stream joining the Missouri River as a barbed tributary just north of where Little Prickly Pear Creek joins the Missouri River. Dog Creek is the southeast oriented Missouri River tributary in the northeast corner of figure 9. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Continuing downstream (or north) along the Missouri River the Dearborn River flows in a south and southeast direction to join the Missouri River as a barbed tributary (figure 10). Dearborn River headwaters are located along the east-west continental divide and are linked by deep passes with headwaters of northwest-oriented Flathead River tributaries, which eventually drain to the Clark Fork River and then to the Columbia River.

Figure 10: Southeast-oriented Dearborn River joins the northeast-oriented Missouri River as a barbed tributary. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Barbed tributaries flowing to the north-oriented Madison River: Many West Fork Madison River headwaters are oriented in south or southeast directions as seen in figure 11.

Figure 11: South and southeast streams and rivers flow to the northeast, southeast, and northeast oriented West Fork Madison River, which joins the north-northwest oriented Madison River near the northeast corner of figure 11. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Continuing downstream (or north) along the Madison River barbed tributaries are found in the Ennis, Montana area. The first is Moose Creek and is shown in figure 12.

Figure 12: Moose Creek flows in a southeast direction to join the north-oriented Madison River near Ennis, Montana. The south and southwest oriented drainage system flowing from the Tobacco Root Mountains in the west half of figure 12 is Granite Creek, which flows to the northwest-oriented Ruby River (which is a Beaverhead River tributary). United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Continuing downstream (or north) along the Madison River valley North Meadow Creek flows in a southeast direction to join the north-oriented Madison River at the north end of Ennis Lake as seen in figure 13.

 

Figure 13: Southeast-oriented North Meadow Creek joins the north-oriented Madison River as a barbed tributary at Ennis Lake. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Barbed tributaries flowing to the north-oriented Gallatin River: The Gallatin River originates in the Yellowstone National Park northwest corner where several barbed tributaries flow in southwest directions to join the northwest, west, north, and northwest oriented Gallatin River near the Montana-Wyoming border as seen in figure 14.

Figure 14: Southwest-oriented streams join the northwest, west, north, and northwest oriented Gallatin River near the Montana-Wyoming border. Note evidence for anastomosing channels in the south center area of figure 14. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Some other excellent examples of barbed tributaries flowing to the north-oriented Gallatin River can be seen further to the north (or downstream along the Gallatin River) in the Big Sky, Montana area as seen in figure 14.

Figure 15: South and southeast oriented tributaries flowing to the north, northeast, and north oriented Gallatin River near Big Sky, Montana. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

Conclusions: Passes across the east-west continental divide in the Henrys Lake area and further to the west along the Montana-Idaho border were originally eroded by a large-scale south-oriented anastomosing channel complex that was active as the surrounding mountains were emerging. Numerous barbed tributaries flowing to the present-day north-oriented Redrock, Beaverhead, Jefferson, Madison, Gallatin, and Missouri Rivers provide additional evidence for this south-oriented anastomosing channel complex. Emergence of mountain ranges along the present-day east-west continental divide dismembered the south-oriented anastomosing  channels and caused reversals of flow to create the present-day north-oriented Redrock, Beaverhead, Jefferson, Madison, Gallatin, and Missouri Rivers. The most likely source supplying water to the south-oriented anastomosing channel complex would be a large continental ice sheet, although commonly accepted geologic models do not recognize a continental ice sheet presence at the time mountains along the present-day east-west continental divide were emerging. Evidence presented here suggests a reinterpretation of Tertiary history evidence is needed to explain this apparent time paradox.

References cited

Clausen, E. N., 2014, COMMENT: “Late Oligocene-early Miocene Grand Canyon: A Canadian connection?: GSA Today, v. 24, no. 4/5, p. e32.

Sears, J.W., 2013, Late Oligocene-early Miocene Grand Canyon: A Canadian connection?: GSA Today, v. 23, p. 4-10.

Sears, J.W., REPLY to Comment: “ Late Oligocene-early Miocene Grand Canyon: A Canadian connection?” GSA Today, v. 24, no. 4/5, p. e33.

Todd, J.E., 1914, The Pleistocene history of the Missouri River: Science, v. 39, p. 263-274.