Topographic map interpretation methods are used to determine landform origins for the Lodge Creek and Battle Creek drainage basins located in the Cypress Hills region of southwest Saskatchewan and southeast Alberta. Lodge Creek and Battle Creek originate in the Cypress Hills upland region and flow in south and southeast directions to join the Milk River in adjacent Montana with water eventually reaching the Gulf of Mexico. North of the Lodge Creek and Battle Creek headwaters are north-oriented drainage basins draining to the South Saskatchewan River (and/or interior drainage basins which would overflow to the South Saskatchewan River) with water eventually reaching Hudson Bay. This north-south continental divide in the Cypress Hills upland region is an asymmetric drainage divide with the more gradual slope to the south. Multiple through valleys cross the present day drainage divide and provide evidence of massive south-oriented flood flow, which once moved across the Cypress Hills upland surface, which is interpreted to have been located near the southwest margin of a rapidly melting thick North American ice sheet, which had been located in a deep “hole”. High level Cypress Hills upland surfaces may be relics of earlier erosion events when immense ice-marginal melt water flood flow was diverted in east and/or northeast directions to move onto the lowering ice sheet surface to reach deep ice-walled canyons being carved by supra glacial melt water rivers. Headward erosion of the deep Battle Creek and Lodge Creek valleys (in that sequence) is interpreted to have occurred during the final major erosion events of the thick ice sheet’s rapid melt down. Following Battle and Lodge Creek valley headward erosion headward erosion of the deep South Saskatchewan River valley captured the ice-marginal flood flow routes in sequence from east to west and triggered massive flood flow reversals to erode what are today north-oriented drainage routes north of the Cypress Hills.
- The purpose of this essay is to use topographic map interpretation methods to explore the Lodge and Battle Creek drainage basin in the Cypress Hills region of Saskatchewan and Alberta, Canada. 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 making a comment here with the links to those essays.
- 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 essays in the Missouri River drainage basin landform origins research project 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 in the Lodge Creek and Battle Creek drainage basins in the Cypress Hills region in Saskatchewan and Alberta, Canada will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm (see paradigm related essay in menu at top of page). This essay is included in the Missouri River drainage basin landform origins research project essay collection.
Lodge Creek and Battle Creek drainage basin area location map
- Figure 1 is an Atlas of Canada Toporama index map showing the Lodge Creek and Battle Creek location in the Cypress Hills region of southwest Saskatchewan and southeast Alberta, Canada. The region south of the index grid is located in Montana (south of the Canada-United States border). The large grid numbers index 1:250,000 scale hard copy topographic maps with maps 72F, 72G, 72K, 72J, 72N, and 72O being located in Saskatchewan and maps 72E, 72L, 72M, 82H, and 82I being located in Alberta. The South Saskatchewan River is labeled in maps 72L and 72K and east and north of the figure 1 map area South Saskatchewan River water eventually reaches Hudson Bay. The Lodge Creek and Battle Creek drainage basins investigated in this knol are located primarily in more detailed grid map areas numbered 72F4, 72F5, 72F12, 72E8, and 72E9 (the more detailed grid numbers identify hard copy 1:50,000 scale topographic maps). Battle Creek is labeled and flows from map number 72E9 in an east and southeast direction into map 72F12. Once in map 72F12 Battle Creek flows in a south direction to map 72F5 where it turns to flow in an east-northeast direction before turning to flow in a south and south-southeast direction into Montana where it joins the east-southeast oriented Milk River (shown, but not labeled in figure 1). Water in the Milk River flows to the Missouri River, which then flows to the Mississippi River and eventually reaches the Gulf of Mexico. The South Saskatchewan River-Battle Creek drainage divide is the north-south continental divide. Lodge Creek is also labeled on figure 1 and originates in map 72E9 and then flows in a southeast direction to the corner of 72E1, 72E8, 72F4, and 72F5 and then to the international border. Lodge Creek joins the Milk River very near the same point where Battle Creek joins the Milk River. East of the Battle Creek elbow of capture near the map 72F5 northeast corner are headwaters of the east- and southeast-oriented Frenchman River (labeled in figure 1) which east of the figure 1 also flows to the Milk River. The South Saskatchewan River-Frenchman River drainage divide area essay describes landform origins in the region east of the Battle Creek drainage basin and the Milk River-Battle Creek drainage divide area, Hill County, Montana essay describes regions south of the international border. Essays are listed under Milk River on the sidebar category list.
- Both Lodge Creek and Battle Creek originate in the western Cypress Hills upland region which straddles the Alberta-Saskatchewan border. The Cypress Hills upland consists of two prominent west to east oriented flat-topped hills which stand high above the surrounding plains with a well-defined through valley eroded between them. As seen in the following topographic maps other through valleys also cross the upland region and the north-facing slope is much steeper and higher than the south-facing slope. The upland surface originated as either an erosion and/or a deposition surface (the distinction cannot be made from topographic map evidence alone) and has since been eroded by massive south-oriented flood flow. To understand the Cypress Hills upland origin a brief review of big picture evidence as summarized from hundreds of Missouri River drainage basin landform origins research project essays is required. The Cypress Hills region was probably located along the southwest margin of what became a rapidly melting thick North American ice sheet (at least during latter stages of the ice sheet’s melt down history). The ice sheet had formed on a topographic surface now preserved, if it is preserved at all, on the highest level Rocky Mountain erosion surfaces. Those high level Rocky Mountain erosion surfaces have probably been significantly uplifted since the ice sheet formation and were probably uplifted by ice sheet caused crustal warping. A combination of ice sheet caused crustal warping and deep glacial erosion of bedrock under the ice sheet created a deep “hole” in the North American continent in which the ice sheet was located. At first the ice sheet stood high above the surrounding region while the ice sheet roots extended far below the elevation of the surrounding regions. Initially immense melt water floods flowed in a south and southeast direction along the ice sheet’s southwest margin across regions being uplifted by ice sheet caused crustal warping. In time the ice sheet surface was lowered to the point where the ice sheet no longer stood high above the surrounding region, but instead was at or lower than the surrounding regions. At the same time giant south- and southeast-oriented supra glacial melt water rivers carved deep ice-walled canyons into the decaying ice sheet surface. Tributary valleys then eroded headward from these large ice-walled (and at first ice-floored) canyons to capture the immense ice-marginal floods.
- A giant southeast and south oriented ice-walled and eventually bedrock-floored canyon played a major role in shaping the entire upper Missouri River drainage basin landscape, including the Cypress Hills region. This giant ice-walled canyon extended in a southeast direction across southern Saskatchewan and into North Dakota where it then extended in a south direction across eastern South Dakota and ended at the ice sheet margin. Today the northeast and east-facing Missouri Escarpment is all that remains of this huge canyon’s southwest and west wall. Late during the ice sheet melt down history this gigantic canyon detached the ice sheet’s southwest margin, although prior to that time east and northeast oriented valleys repeatedly eroded headward from this deepening canyon to capture massive south and southeast oriented ice-marginal melt water floods and to divert the flood waters onto the ice sheet surface. These deep east and northeast oriented valleys eroded headward into what is now the Rocky Mountain region where ice sheet caused crustal warping was uplifting mountain ranges as immense melt water floods flowed across them. At some point in the ice sheet melt down history a large east and/or northeast-oriented melt water river flowed in one of these east and/or northeast-oriented tributary valleys from the rising the Rocky Mountain region onto the ice sheet surface in the Cypress Hills region and then across the ice sheet surface in an ice-walled canyon to the large southeast- and south-oriented ice-walled canyon. Over time as the ice sheet surface became lower and the floor of the ice-walled canyon also became lower the east and/or northeast-oriented valley migrated in an east and southeast direction downstream along the giant southeast-oriented ice-walled canyon route. At one time the east and/or northeast-oriented melt water crossed the ice sheet margin near the present day Wood Mountain upland east of the Cypress Hills. Later the river crossed the ice sheet margin near the Flaxville upland in northeast Montana. Finally, very late in the ice sheet’s melt down history, a deep east and northeast-oriented valley eroded headward from what was then an ice-walled and bedrock-floored canyon across the present day Medicine Lake area in northeast Montana. Upstream from Poplar, Montana the Missouri River valley is now that east and northeast-oriented tributary valley and the Milk River valley was eroded headward as a tributary to that new east and northeast-oriented valley. The Lodge Creek and Battle Creek drainage basins were eroded at that time. Subsequently, as the Lodge Creek and Battle Creek drainage basins were being eroded the deep northeast-, east-, and northeast-oriented South Saskatchewan River valley eroded headward from the ice-walled and bedrock-floored canyon and captured much of the ice-marginal flood flow which had been flowing to the newly eroded Missouri River valley and its tributary valleys, including the Milk River valley and its tributary valleys such as the Lodge Creek and Battle Creek valleys.
Seven Persons Creek-Lodge Creek drainage divide area
- Figure 2 uses a Toporama 1:300,000 scale topographic map to illustrate the Seven Persons Creek-Lodge Creek drainage divide area at the west end of the Cypress Hills upland region. Medicine Hat, Alberta is located in the southeast quadrant of map 72L2 and the river flowing through Medicine Hat is the South Saskatchewan River. The northeast-oriented tributary joining the South Saskatchewan River near Medicine Hat and flowing across the west half of map 72E15 is Seven Persons Creek (note town of Seven Persons near the creek). The high upland surface seen in map 72E9 is the west end of the Cypress Hills upland. South-oriented drainage flowing to the figure 2 south edge in map 72E9 flows to Lodge Creek with Lodge Creek draining the south-southeast end of the large north-northwest to south-southeast oriented through valley seen near the west margin of map 72E9. Battle Creek is the east-oriented stream in map 72E9 originating on the Cypress Hills upland surface and flowing along the Cypress Hills north flank to the map 72E9 east edge. Other than some south-oriented drainage routes in map 72E7 all other figure 2 drainage routes are in the South Saskatchewan River drainage basin or drain to interior drainage basins, which should they overflow would drain to the South Saskatchewan River. Note elevations in the figure 2 map area where highest elevations in the Cypress Hills upland region are shown in map 72E9 where Battle Creek originates at elevations greater than 1420 meters. Southwest-oriented Lodge Creek headwaters originate at elevations of almost 1400 meters and then turn to flow in south-southeast direction in a through valley which has a floor elevation of between 1160 and 1180 meters. Elevations in the South Saskatchewan River valley downstream from Medicine Hat are less than 700 meters. Elevations in the Seven Persons Creek valley are less than 800 meters while elevations in the figure 2 southwest corner are less than 900 meters. The Seven Persons Creek-Lodge Creek drainage divide is an asymmetric drainage divide with a much steeper slope on the north and northwest face than to the south. The map evidence suggests the Lodge Creek valley and probably the Battle Creek valley (we need to see the area to the east before we can be sure) were eroded by south-oriented flood flow from north of the present day drainage divide. If so, at that time the region north of the drainage divide was at least as high as the present day drainage divide if not higher. Whether the region north of the drainage divide was filled with bedrock, which has since been removed by melt water flood erosion, or with ice, which has since melted, cannot be easily be determined, but more detailed maps may help.
Bullshead Creek-Lodge Creek drainage divide area
- Figure 3 uses a 1:150,000 scale topographic map to provide a more detailed look at the Lodge Creek headwaters region seen in less detail in figure 2 above. The north-south oriented through valley drained by south-oriented Lodge Creek is labeled Medicine Lodge Coulee on figure 3. Lodge Creek (not labeled in figure 3) originates as a southwest-oriented stream in map 72E9 and flows into Medicine Lodge Coulee and then flows in a south direction to the figure 3 south edge (just east of center). Read Creek and Thelma Creek are Lodge Creek tributaries. Note how Thelma Creek begins as a southeast oriented stream at an elevation of at least 1420 meters. The southeast oriented Thelma Creek headwaters may be a relic of southeast-oriented ice-marginal flood flow along a high-level topographic surface at least as high as the highest Cypress Hills elevations today. Also note the shallow north-south oriented through valley (defined by one contour line on each side) between the south-oriented Thelma Creek valley and the north-oriented stream at Elkwater Lake. The deep Medicine Lodge Coulee through valley links the north-oriented Bullshead Creek valley with the south-oriented Lodge Creek valley. At the drainage divide the through valley floor elevation is between 960 and 980 meters. Elevations to the east rise to 1465 meters and to the west elevations rise to at least 1320 meters. This Bullshead Creek-Lodge Creek through valley is not the only through valley seen. Just to the west is a through valley between a south-southeast oriented Lodge Creek tributary and northwest-oriented Peigan Creek and in the northwest corner of map 72E8 (near the figure 3 south edge) is still another northwest-southeast-oriented through valley. These through valleys provide evidence of multiple southeast- and south-oriented flood flow routes across the present day drainage divide. At one time flood waters flowed on a topographic surface at least as high as the highest through valley floor (1420 meters) and all lower elevations were the result of erosion by southeast- and/or south-oriented flood flow and/or by reversals of that flood flow to flow in north and northwest directions to what later became the much deeper South Saskatchewan River valley to the north. Through valleys linking north-oriented drainage routes illustrate how reversed flood flow eroded the Cypress Hills north-facing slope. For example, Bullshead Creek originates at Fly Lake as a southwest-oriented stream which then turns to flow in a north and northwest direction. Note how Fly Lake is linked by through valleys to north and north-northeast oriented valleys to the east. South and southeast-oriented flood waters were beheaded in sequence from east to west by South Saskatchewan River valley headward erosion. Flood waters on newly beheaded flood flow routes reversed flow direction to erode north-oriented valleys. South and southeast-oriented flood flow from further west (not yet beheaded by deep South Saskatchewan River valley headward erosion) was captured by the newly reversed flood flow channel and flowed in an east and then north direction to the newly eroded South Saskatchewan River valley.
Detailed map of Bullshead Creek-Lodge Creek drainage divide area
- Figure 4 uses a 1:40,000 scale topographic map to better illustrate the Bullshead Creek-Lodge Creek drainage divide area. Note how elevations in figure 4 are shown in feet rather than meters as in figures 2 and 3. The deep north-south oriented Medicine Lodge Coulee through valley is located in the figure 4 east half and is drained at the north by north-oriented Bullshead Creek (which is labeled). The stream draining the through valley south end is Lodge Creek (unlabeled in figure 4) which flows to the figure 4 south edge (just west of the southeast corner). Sexton Creek is a Lodge Creek tributary. The through valley floor at the drainage divide appears to be slightly less than 3750 feet (but more than 3725 feet). Elevations to the west appear to rise to more than 4350 feet while elevations to the east rise even higher suggesting the valley is at least 600 feet deep. This is a significant north-south oriented through valley which was eroded by south-oriented melt water flood flow. In the figure 4 southwest quadrant the Peigan Creek tributary-Lodge Creek tributary through valley is also shown. The through valley floor elevation at the drainage divide is between 3775 and 3800 feet only slightly higher than the floor of the Bullshead Creek-Lodge Creek through valley. The similarity of the valley floor elevations of these two different, but roughly parallel through valleys suggests southeast and south-oriented flood flow was moving in both valleys at the same time. This evidence suggests the presence of a large southeast and/or south-oriented anastomosing channel complex eroding deeply into the high level topographic surface, which once extended across the entire region. A close look at the figure 4 map area reveals other through valleys eroded across what is today the north-south continental drainage divide and also linking the west and northwest-oriented Peigan Creek headwaters. These valleys are difficult to explain unless flood waters originally flowed on a high level topographic surface at least as high as the highest Cypress Hills elevations today. If so all lower elevation regions surrounding the Cypress Hills upland were eroded by the immense south-oriented flood flow and the massive reversals of that flood flow caused by headward erosion of the deep “northeast-oriented” South Saskatchewan River valley.
Mackay Creek-Battle Creek drainage divide area
- Figure 5 uses a 1:150,000 scale topographic map to illustrate the Mackay Creek-Battle Creek drainage divide area located east of the figure 3 map area and includes overlap areas with figure 3. Mackay Creek is labeled and originates in the map 72E9 northeast corner and generally flows in a north direction to the figure 5 north edge (near northeast corner). North of the figure 5 map area water in Mackay Creek ends up in an interior drainage basin, which should it ever overflow would drain to the South Saskatchewan River. Battle Creek is also labeled and as previously mentioned originates on the high Cypress Hills upland surface (near the number “72E9”) and then flows in an east direction along the Cypress Hills upland north flank before turning to flow in a southeast direction to Fort Walsh near the figure 5 southeast corner. The southeast-oriented Battle Creek valley cuts completely across the Cypress Hills upland region, which can be better seen in figure 7. Lodge Creek drains the south end of Medicine Lodge Coulee seen near the figure 5 west edge. Note how north-south oriented through valleys link north-oriented Mackay Creek headwaters with the east-oriented Battle Creek valley. One through valley is located near Reesor Lake while another through valley is located near the east edge of map 72E9. The through valleys are better illustrated in figure 6, although from figure 5 evidence they both appear to have valley floor elevations of between 1200-1220 meters. The similarity of the floor elevations suggests south oriented flood flow moved in both valleys at the same time, which means regions north of the through valleys were at least as high as the 1200-1220 meters level at the time flood waters ceased flowing south in the Battle Creek valley. Remember at that time the Battle Creek valley along the Cypress Hills north flank had already been eroded 200 or more meters into the high level topographic surface which was previously crossed by south- and/or southeast-oriented flood flow. Today the Mackay Creek valley elevation near the figure 5 northeast corner is 820 meters, meaning there has been up to 600 meters of material removed from north of the Cypress Hills upland surface remnants. It is possible much of the removed material was ice, which may have filled much of the region north of the present day Cypress Hills north-facing slope. However, east-oriented Mackay Creek tributaries provide evidence that reversed flood flow on the Mackay Creek alignment (which would have been beheaded and reversed by headward erosion of the deep South Saskatchewan River valley prior to reversal of south-oriented flood flow on the Bullshead Creek alignment) captured south-oriented flood flow from further to the west and diverted that captured flood flow in an east direction to the newly reversed flood flow on the Mackay Creek alignment.
Detailed map of Mackay Creek-Battle Creek drainage divide area
- Figure 6 uses a 1:40,000 scale topographic map to illustrate the Mackay Creek-Battle Creek drainage divide area seen in less detail in figure 5 above. Battle Creek flows in an east-southeast direction from the figure 6 west edge (south half) to the figure 6 south edge (east half near southeast corner). Reesor Lake drains in a southeast direction to Battle Creek. South and east of figure 6 Battle Creek flows to the Milk River with water eventually reaching the Gulf of Mexico. North-oriented Mackay Creek is labeled and is located in the figure 6 east half and all other north-oriented streams are Mackay Creek tributaries. North and east of figure 6 Mackay Creek water flows to an interior drainage basin, although should that basin ever overflow water would flow to the South Saskatchewan River and eventually reach Hudson Bay. In other words the Mackay Creek-Battle Creek drainage divide is also the north-south continental divide. Several through valleys link north-oriented Mackay Creek tributary valleys with the southeast-oriented Battle Creek valley. The deepest through valley is south of an intermittent lake in the figure 6 southeast quadrant. The map 72E9 contour interval is 25 feet (the contour interval in map 72F12 is 10 meters) and the through valley floor elevation at the drainage divide is between 3925 and 3950 feet. Elevations on either side of the through valley rise to approximately 4500 feet meaning the through valley is more than 500 feet deep. A somewhat narrower and shallower through valley is located just to east and has a valley floor elevation of between 4175 and 4200 feet. Another deep through valley is located west of Reesor Lake and links a northeast-oriented Mackay Creek tributary valley with the southeast-oriented Reesor Lake valley. The floor of this western deep through valley has a floor elevation of between 4025 and 4050 feet and is slightly higher than the eastern deep through valley. The high ridge north of Battle Creek between the western and eastern deep through valleys is crossed by other much narrower and shallower through valleys the deepest of which has a valley floor elevation of between 4375 and 4400 feet. These through valleys were eroded by multiple south-oriented flood flow channels moving flood waters to what was at that time the actively eroding Battle Creek valley. Initially flood waters flowed across a topographic surface at least as high as the highest figure 6 elevations today (greater than 4500 feet) and the flood flow channels were eroded headward into the high level topographic surface north of the Cypress Hills upland surface. At least some of the material into which the flood flow channels were eroded may have been ice along the southwest margin of the decaying North American ice sheet. Melting of ice and/or deep erosion of bedrock north of the Cypress Hills upland region systematically reversed the south-oriented flood flow channels to create north-oriented drainage routes that eroded the north-facing slope.
Lodge Creek-Battle Creek drainage divide area
- Figure 7 uses a 1:300,000 scale Toporama topographic map to provide a big picture view of the Lodge Creek-Battle Creek drainage divide area in the Cypress Hills region. Streams are not labeled, but I will try to identify major drainage routes here. Lodge Creek originates in the west half of map 72E9 and flows in a south-southeast and southeast direction to the corner of maps 72E1, 72E8, 72F4, and 72F5 and then to the figure 7 south edge (just west of center). Battle Creek flows from the Cypress Hills north flank in map 72E9 and in a southeast and south direction across the southwest quadrant of map 72F12 into map 72F5 where it turns to flow in an east-northeast direction to the northeast corner of map 72F5 where it again turns to flow in a south-southeast direction into map 72F6. Once in map 72F6 Battle Creek makes a southwest jog across the map 72F5 southeast corner and then flows in a south-southeast direction across the map 72F4 northeast corner to the figure 7 south edge. East of the Battle Creek elbow of capture in the map 72F5 northeast corner is Cypress Lake (not labeled, but shown) which is the headwaters of the east- and southeast-oriented Frenchman River. The Frenchman River flows along the Cypress Hills upland south flank before eventually turning to the southeast and joining the Milk River. North-oriented drainage routes flowing to the figure 7 north edge flow to interior drainage basins located between the Cypress Hills and the South Saskatchewan River. While today the interior drainage basins have no outlets should they ever overflow the flow would be to the South Saskatchewan River. Note how the east-northeast oriented Battle Creek valley segment in map 72F5 is aligned with Cypress Lake and the east-oriented Frenchman River valley. Also note the large through valley in map 72F12 between the East and West Cypress Hills upland regions. A south-oriented Battle Creek tributary (Oxarat Creek) drains the through valley’s south end while a north-oriented stream (Gap Creek) drains the north end. The Battle Creek valley west of Cypress Lake probably was initiated as a westward extension of the Frenchman River valley, which eroded headward across massive south-oriented flood flow. Concentrated south-oriented flood flow in the deep through valley then overwhelmed the newly eroded Frenchman River valley to erode the deep Battle Creek valley headward from what was then the actively eroding Milk River valley to the south. Headward erosion of the deep Battle Creek valley captured the west end of the Frenchman River valley system while to the north south-oriented flood flow routes were beheaded and reversed in sequence from east to west. In other words south-oriented flood flow through the Gap ended while south-oriented flood flow was continuing to flow to the east-oriented Battle Creek valley in map 72E9.
Gap Creek-Oxarat Creek drainage divide area
- Figure 8 uses a 1:150,000 scale Toporama topographic map to illustrate the Gap Creek-Oxarat Creek through valley seen in less detail in figure 7 above. The Gap is the large north-south oriented through valley between the West Cypress Hills upland and the East Cypress Hills upland. Elevations shown on the West Cypress Hills upland rise to more than 1340 meters while elevations on the East Cypress Hills upland rise to more than 1260 meters. Elevations at the drainage divide in the Gap through valley are between 1080 and 1100 meters making the The Gap at least 160 meters deep. Today the Gap through valley is drained to the north by Gap Creek, which flows to northeast-oriented drainage routes. Those drainage routes end at interior basins, although should the interior drainage basins ever overflow the water would go to the north-oriented South Saskatchewan River and eventually reach Hudson Bay. The Gap through valley south end is drained by Oxarat Creek, which is a Battle Creek tributary with water eventually reaching the Gulf of Mexico. Note on the west side of the Gap through valley an unlabeled south-oriented stream with headwaters at Adams Lake and also at Coulee Lake. That stream flows in a separate valley linking north-oriented drainage routes with the south-oriented Battle Creek valley. Battle Creek is seen in figure 8 flowing in a south-southeast and south direction from the figure 8 west edge (just north of center) to the figure 8 south edge (near southwest corner). As seen in earlier figures Battle Creek has eroded a deep valley across the West Cypress Hills upland surface. Note the asymmetric drainage divide, which is especially noticeable along the north edge of the East Cypress Hills upland region. South-oriented Frenchman River tributaries, including Weaver Creek, originate almost at the edge of the north-facing slope. This evidence suggests the south-oriented drainage routes originated at a time when the entire region was at least as high as the present day Cypress Hills upland surface. The simplest explanation is the north-facing slope represented at that time the south or southwest margin of the decaying North American ice sheet, although it is also possible melt water flood erosion of easily eroded bedrock in regions north of the Cypress Hills produced the north-facing slope seen today. Regions south of the Cypress Hills upland were eroded by the massive south-oriented flood flow, which was beheaded and reversed in sequence from east to west to create the present day drainage divide.
Detailed map of Battle Creek-Frenchman River drainage divide area
- Figure 9 uses a 1:40,000 scale Toporama topographic map to illustrate in detail the Battle Creek-Frenchman River drainage divide area seen in less detail in figure 7 above. Battle Creek is labeled and flows in an east-northeast direction from the figure 9 west edge (south of center) and then turns to flow in a south direction to the figure 9 south edge (west of center). Oxarat Creek, which drains the south end of The Gap through valley flows in a south direction from the figure 9 north center edge and then turns to flow in a southwest direction to join the east-northeast oriented Battle Creek valley. Cypress Lake is impounded behind a dam located east of the figure 9 map area and drains to the east- and southeast-oriented Frenchman River valley. The dam is high enough that water can also drain in a northwest and/or southwest direction in the valleys located west of the lake to reach the south-oriented Battle Creek valley. Note how the east-northeast oriented Battle Creek valley segment is linked by a well-defined through valley with the Cypress Lake basin, which is the east-oriented Frenchman River valley. Also note how the south-oriented Oxarat Creek valley originally probably drained to the Frenchman River valley. Some rearranging of drainage routes may be related to recent human activity, although there can be no question that at one time water flowed from the present day east-northeast oriented Battle Creek valley segment to the Frenchman River valley. This east-oriented flood flow route was captured by headward erosion of the south-oriented Battle Creek valley segment. This south-oriented Battle Creek valley did not erode headward as a single valley, but eroded headward as a series of south-oriented flood flow channels such as might be found in an anastomosing channel complex. Evidence for these other flood flow channels can be found in the form of through valleys crossing the ridge south of the east-northeast oriented Battle Creek valley segment and the east-oriented Frenchman River valley. One such through valley can be seen west of the south-oriented Battle Creek valley segment and is drained by a north-northwest oriented Battle Creek tributary. The north-northwest oriented Battle Creek tributary valley was eroded by a reversal of flood flow on the north end of a beheaded south-oriented flood flow route. Another through valley can be seen south of Cypress Lake along the figure 9 east edge and links the east-oriented Frenchman River valley with a south-oriented Battle Creek tributary valley located south of the figure 9 map area.
Map of Cypress Hills-international border region
- Figure 10 provides a Toporama 1:300,000 scale topographic map to illustrate the Lodge Creek-Battle Creek drainage divide region between the Cypress Hills upland surface and the Canada-United States border. Again drainage routes are not labeled, but Lodge Creek is the southeast-oriented stream flowing to the map 72E8 southeast corner and then to the figure 10 south edge. Battle Creek flows in a south-southeast and south direction in map 72F12 and then in map 72F5 turns to flow in an east-northeast direction to the map 72F5 northeast corner where it turns to flow in a south-southeast direction into map 72F6 where it makes a southwest jog before flowing in a southeast and south direction again. Elevations in the Lodge Creek and Battle Creek valleys near the figure 10 south edge are less than 900 meters compared with elevations greater than 1400 meters in the western Cypress Hills upland region and elevations of less than 800 meters north of the Cypress Hills. Generally slopes on the Cypress Hills south flank are less steep and much more gradual than slopes along the Cypress Hills north flank. This difference in slopes provides further evidence of the asymmetric drainage divide in addition to the south-oriented streams originating at the crest of the north-facing slope and/or as in the case of Battle Creek actually flowing for a distance along the flank of the north-facing slope before crossing the Cypress Hills upland in a deep valley. The asymmetric drainage divide is evidence the entire region was eroded by massive south- and/or southeast-oriented flood flow. As the deep east-oriented Milk River valley south of the international eroded headward into a high level topographic surface flood waters lowered the region between the Wood Mountain and Cypress Hills upland regions and the newly eroded deep Milk River valley. The Frenchman River valley (today originating at Cypress Lake in the northwest corner of map 72F6) was eroded headward across the immense south-oriented flood flow from the actively eroding deep Milk River valley to the south and east and diverted flood waters in an east and southeast direction to the newly eroded Milk River valley. Next the deep Battle Creek valley (and soon thereafter the deep Lodge Creek valley) eroded headward from the actively eroding Milk River valley head (which by that time had eroded further west). As already described Battle Creek valley headward erosion probably captured what was then the west end of the developing Frenchman River valley system, which represents the Battle Creek valley system upstream from the map 72F5 northeast corner. Finally headward erosion of the deep South Saskatchewan River valley north of the figure 10 map area beheaded the south- and/or southeast-oriented flood flow routes in sequence (from east to west) and triggered massive reversals of the south-oriented flood flow to erode north-oriented drainage routes.