Devils Lake, North Dakota

Scott Jones
Fall 2008
Quaternary Geology * Emporia State University

Location and Early History

Formation of Lake by Glaciers

The Problem with Devils Lake

Conclusion
References

Figure 1-Map of the Devils Lake area, North Dakota. (USGS, 2008).

Glaciers have played a significant role in shaping much of the Northern Great Plains including North Dakota. An area in eastern North Dakota known as Devils Lake formed under the influence of glaciers, but the result was much different than that of a typical glacial lake. This webpage describes the location and early history of the area, the glacial events and processes that took place, and the problems associated with Devils Lake.

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Location and Early History

Devils Lake is located in northeastern North Dakota, and it is situated in the Devils Lake Basin and the larger Red River Basin (Figure 2). The Devils Lake Basin encompasses 9,868 square kilometers, which makes Devils Lake the largest lake in North Dakota (USGS, 2008). The Red River flows into the lake from the north and recharges the water supply; although, the lake is unusual because it has no channels acting as outlets for the water. If there is excessive precipitation and runoff the lake will overflow its boundaries and spill into smaller lakes and channels. Throughout time the lake has had overflowing conditions on numerous occasions.

Figure 2-Location map of Devils Lake, North Dakota; and the glacial landforms of the surrounding region. (permission to use; Aber, 1997).

Approximately two and half million years ago the Devils Lake Basin looked much different than present. The surface rock was a gray, calcareous, fine-grained shale referred to as the Pierre Formation (Laird, 1957). It was a soft, marine shale that was deposited in a shallow sea about 70 million years ago during the Cretaceous Period. At the end of the Cretaceous Period (65 million years ago) the climate in North Dakota started to cool, and it continued to cool throughout the Tertiary. A series of river systems also developed that created many deep valleys in the shale. These river systems drained much of North Dakota to the northeast to the Hudson Bay area. One of the major river systems was the Cannonball River, and the erosion caused by it and other rivers set the stage for glacial paths (USGS2, 2008).

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Formation of Lake by Glaciers

Approximately two and a half million years ago glaciers began to form near the Hudson Bay area. Shortly thereafter glaciers made their way into North Dakota, where they would make there presence felt up until approximately 10,000 years ago (USGS3, 2008). The glaciers advanced into North Dakota from the north, and with every advance the drainage of water was diverted towards the southeast along the glaciers’ edge. Every advance led to later retreats, which meant extensive deposition of glacial deposits by the glaciers themselves or by the meltwater that carried sediments such as sand and gravel. The sand and gravel was usually deposited in the pre-glacial valleys such as the Cannonball River Valley, but the sand and gravel was later covered by glacial sediments from other advancing and retreating glaciers. The deepest valleys with deeply buried sand and gravel sediments were perfect sites for underground aquifers. One aquifer, the Spirtwood, was located at the site of modern day Devils Lake. The Spirtwood Aquifer is still one of North Dakota’s largest aquifers (Bluemle, 2005).

During the Late Wisconsin, approximately 12,000 years ago, a large glacier made its way into eastern North Dakota and the Devils Lake area. The old surface shale was covered by enormous amounts of glacial sediments that were encrusted in a permafrost state (Bluemle, 2005). As the glacier moved south it ran over the Spirtwood Aquifer (Figure 3a). The aquifer was pressurized at the time due to the overlying permafrost acting as a seal and by the weight of the advancing glacier (Figure 3b). As the glacier advanced the water pressure within the aquifer rose dramatically, but the only place for the water to escape was upwards (Figure 3c). The upward movement of water forced materials in front of the path of the glacier that pushed the materials a few kilometers farther to the south where the glacier stopped advancing (USGS2, 2008). The area the materials had been removed from was now a depression below the glacier. The upward movement of materials is generally known as a thrusting event.

When the glacier stopped advancing it lost its ability to smooth off the materials it had removed and fill in the areas the materials originated from. The result of this unusual ice thrusting event was the Devils Lake area (Figure 3d). The area consists of ice-shoved hills that are composed of brecciated mixtures of glacial sediments and pre-glacial shale beds (Figure 2). Sullys Hill and Crow Hill, along with other hills, lie to the south of a string of internally connected glacial basins that are now flooded by Devils Lake, which has no outlet (Aber et al., 1997). An individual hill and basin are termed a hill-hole pair.

Figure 3-Sequence of formation of Devils Lake, North Dakota. (a) Glacier advances towards Cannonball River Valley; (b) Weight of glacier adds pressure to underlying aquifer; (c) Forced upward movement of water and sediments as glaciers advances into and above the pressurized area; and (d) Glacier advance ceases, glacier retreats leaving Sullys Hill and unfilled depression: later known as Devils Lake (USGS2, 2008; from Bluemle: personal communitcation, 1991)

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The Problem with Devils Lake

Devils Lake has provided many things to eastern North Dakota, but the level of it fluctuates often and causes major problems. When the glaciers retreated out of the area at the end of the most recent Ice Age the depressions became flooded and known as Lake Minnewaukan (Bluemle, 2005). This lake was larger than the modern day Devils Lake, and it actually rose to extreme heights that allowed the lake water to overflow into channels and lakes to the south. As the glaciers retreated farther, the water level dropped and the lake became separated into two major lakes, Devils to the north and Stump to the south. Water level since has risen and fallen on a number of occasions, and there have been instances when Devils Lake overflowed into Stump Lake, which eventually overflowed into the Sheyenne River (Figure 4). Both lakes have also dried up on several occasions with one occurring during the Altithermal Period, 7,000 to 5,000 years ago (Bluemle, 2005).

Devils Lake will spill over into Stump Lake when the water level reaches greater than 441 meters above sea level. At 445 meters above sea level Stump Lake and Devils Lake will spill over into the Sheyenne River causing major flooding.

Figure 4-Eastern margin of Devils Lake during a flooded period (copyrighted image, permission to use; Aber, 2004).

According to Bluemle (2005) the reasons for the fluctuations may somewhat be attributed to underlying Spirtwood Aquifer. When bouts of drought or spells of precipitation occur the lake immediately responds; whereas, the aquifer tends to react much slower. During longs spells of precipitation the aquifer may become full and start to leak out into the lake, raising the water level. During periods of drought the aquifer may not be fully charged; therefore, the lake water may flow freely into the aquifer. If it becomes wet again and the aquifer is still not flow, then the lake will be taking on water but it will still be lowering as it gives the water to the aquifer. Overall, the changes of water-level at Devil Lake resulted entirely from long-term climatic events (Aber, 1997).

The residents who occupy the land in the area of Devils Lake have a goal to stabilize the level of it someday. The inability to control it has caused loss of commercial navigation, recreation, and fish kills during low level times. During high level episodes the lake water causes damage to road, infrastructure, residential and commercial buildings, and agriculture production (DLACCTC, 2008). Currently the ideas to remedy the fluctuations have failed due to legal, financial, environmental, international treaty, and water quality constraints; the ideas also fail to meet U.S. Army Corp. of Engineers guidelines. The Devils Lake community supports a “three-stooled” approach that involves 1) storage of water in the upper basin, 2) raise and rebuild the local infrastructure, and 3) construction of an emergency outlet for Devils Lake (DLACCTC, 2008).

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Conclusion

Devils Lake is an unusual system that was a product of a number of circumstances. First, the pre-glacial surface rock was an easily eroded shale that allowed the formation of river valleys. The river valleys made excellent locations for sedimentation and later the formation of saturated sediments and aquifers. Second, the glacier flowed over and into a pressurized aquifer system and ceased advancement just to the south of the aquifer area. The sediments within the aquifer system were easily removed and transported upward to the front of the glacier’s path. Finally, the lack of farther glacial advancement did not allow further smoothing and filling of the topography, which left the aquifer depression open and all drainage possibilities blocked with glacial sediments. This made Devils Lake a closed system with no outlets. Over time, the fluctuations of water level at Devils Lake became a problem due to the amount of upper lake and down valley flooding during wet periods and lake of water during dry periods. It is still quite a mystery as to why the water level fluctuates; although, there is much support for the idea that the underlying aquifer is partly to blame. The truth is the glacial activity is to blame because without the glacier Devils Lake would not exist.

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References

Aber, J.S., Spellman, E.E., Webster, M.P., and L.L. Rand. 1997. Applications of landsat imagery in the Great Plains. Transactions of the Kansas Academy of Science, vol. 100, no. ½, p. 47-60. http://www.kansasacademyscience.org/TKAS/trans100/sympos96/aber/aber.htm [retrieved on 24 Nov. 2008].

Aber, J.S. 2004. North Dakota blimp and kite aerial photography. http://www.geospectra.net/kite/n_dakota/n_dakota.htm [retrieved on 25 Nov. 2008].

Bluemle, J. last update 2005. The origin and behavior of Devils Lake. https://www.dmr.nd.gov/ndgs/Devils_Lake/Orgin_Devils_Lake.htm [retrieved on 24 Nov. 2008].

Laird, W.M., 1957. Guidebook for Geologic Field Trip in the Devils Lake Area, North Dakota. North Dakota Geological Survey Miscellaneous Series, no. 3, 1-11.

Devils Lake Area Chamber of Commerce Tourism Committee (DLACCTC). 2008. The Devils Lake flood story. http://www.devilslakend.com/tourism/flood.htm [retrieved on 25 Nov. 2008].

United States Geological Survey (USGS). last update 2008. Devils Lake Basin in North Dakota. http://nd.water.usgs.gov/devilslake/index.html [retrieved on 25 Nov. 2008].

United States Geological Survey (USGS2). last update 2008. Geology of the Devils Lake Basin. http://nd.water.usgs.gov/devilslake/science/geology.html [retrieved on 25 Nov. 2008].

United States Geological Survey (USGS3). last update 2008. Science of Devils Lake Basin. http://nd.water.usgs.gov/devilslake/science/index.html [retrieved on 25 Nov. 2008].

This webpage was designed for Quaternary Geology
Instructor: Dr. James S. Aber of Emporia State University
For questions or comments contact Scott Jones
Created on November 23, 2008