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Summer 2006: North Dakota's Mountains

Posted by Ed Murphy 10/20/2016 1:13:41 PM

As North Dakotans, we are pretty loose with our usage of the geographic term "mountain." We call landforms that rise a few hundred feet above the surrounding countryside mountains, while our neighbors in South Dakota call a feature that rises more than 4,000 feet above the surrounding area a hill (Black Hills).


Does the need to call a hill or butte a mountain fall within North Dakotan's fondness for bragging about our cold weather? As it turns out, we are not alone. This kind of inconsistency exists not only between states, but within states themselves.


A mountain is defined by the Merriam-Webster Online Dictionary as a "landmass that projects conspicuously above its surroundings and is higher than a hill, an elongated ridge, or a great mass." A butte is defined as "an isolated hill or mountain with steep or precipitous sides usually having a smaller summit area than a mesa."


At one time, the United States Board of Geographic Names defined a mountain as a feature that had at least 1,000 feet of local relief, anything less was considered a hill. However, they abandoned that definition in the early 1970s. There are no longer any official standards for topographic features in the United States because the board found it impossible to reach a broad consensus.


The propensity to name relatively low topographic features mountains can be traced back to some of the earliest explorers in North Dakota. La Verendrye, in his travels across the prairie from Fort La Reine (near Winnipeg, Manitoba) to the Mandan Villages (near present-day Bismarck) in 1738, noted the presence of two mountains. The "first" mountain was likely something he had seen in what is present-day Manitoba. The "second mountain" that he referred to is likely the Turtle Mountains.


Seven official mountains

A search of the United States Geological Survey geographic names information system lists seven features in North Dakota that are officially called mountains:

  • Blue Mountain in western Nelson County
  • Devils Lake Mountain in south-eastern Ramsey County
  • Killdeer Mountains in northwestern Dunn County
  • Lookout Mountain in northeastern Eddy County
  • Prophets Mountains in western Sheridan County
  • Tracy Mountain in southern Billings County
  • Turtle Mountains in northeastern
  • Bottineau and northern Rolette counties.


The Pembina Hills in northeastern Cavalier and northwestern Pembina counties were listed in a 1930s guidebook of North Dakota as the Pembina Mountains, but that name is no longer commonly used. In comparison, Minnesota calls 29 topographic features mountains and South Dakota claims 69. None of the topographic features that are called mountains in North Dakota meets the United States Board of Geographic Names old definition of a mountain; that is, none of these have at least 1,000 feet of local relief. It is likely that few, if any, meet these criteria in either South Dakota or Minnesota.


Name origins elusive


The origin of the names of most of these "mountains" and other topographic features is obscure. Generally, as with all geographic features in the state, the mountains, buttes, or hills were either named by native people, early explorers, fur traders, or the first settlers. The maps and journals of early explorers such as David Thompson, La Verendrye, John Fremont, Jean Nicollet, Meriwether Lewis and William Clark are generally the most definitive sources for names.


We know that the native people living in the area had names for the prominent geographic features. Often, the early explorers or fur trappers translated these Indian names into French or English. For example, the Killdeer Mountains were initially called the Turtle Mountains or Turtle Hills by native people living in the Knife River Indian Villages. David Thompson, the famous English- Canadian explorer and geographer, plotted the Killdeer Mountains on his 1798 map of the Knife River area and labeled them as Turtle Hill. In his journal, he referred to them as Turtle Mountain and Turtle Mountain of the West. Thompson's source for the name was likely the Mandan or Hidatsa living in the Knife River Indian Villages.


When the Corps of Discovery passed through the area in the spring of 1805, William Clark labeled them as Turtle Mountain on his map of the area. In addition, both Clark and Meriwether Lewis referred to Turtle Mountain in their journal entries of April 12, 1805. We know that Lewis and Clark carried Thompson's 1798 map with them on their journey. In spite of this early documented usage of Turtle Hill, that name was not carried forward to today. Instead, the Killdeer Mountains are believed to have received their name from a translation of the Sioux name applied to the mesas "Tah-kah-o-kuty" which means "the place where they kill deer." Therefore, for whatever reason, the Sioux name has persisted over the Mandan and Hidatsa name.


When journals of the early explorers do not document usage of a particular geographic name, we are often left to search local newspapers and county jubilee or centennial history books for information.


For example, the Sheridan County Heritage '89: A Centennial Project published by the McClusky Gazette contains an article entitled "How Prophet's Mountain Got Its Name." According to this article, an old Gros Ventres medicine man had a vision that a flood would come from the north and everything in the area would be covered with water except two prominent ranges of hills. The flood came, and those that had heeded his warning and taken refuge in the hills survived. To honor his prophecy, one of those ranges of hills was named Prophets Mountains. The Prophets Mountains rise approximately 350 feet above the surrounding countryside and extend over an area of approximately 96,000 acres.


WPA project gathered name origins 

In the 1930s, the Works Progress Administration (WPA) funded a history project that canvassed local residents to determine, among other things, the origin of the names of local geographic features. While this may be a valuable source of information for other things, a search of the WPA records in the archives of the State Historical Society of North Dakota yielded little useful information in regard to the origin of the topographic features in question.


For several of these features we are left to speculate on the origin of the name. Blue Mountain in western Nelson County appears to have derived its name from the fact that it appears blue on the horizon, but I was unable to determine what person or group of people first applied that name.


Tracy Mountain is located within the Badlands topography of the Little Missouri River Valley in southcentral Billings County. The first settlers in the Badlands were predominantly of English, Welch, and Irish descent. Tracy, an Irish family name, may have come from a family that lived at or near this landmark.


To belabor the inconsistency that exists in naming topographic features, Tracy Mountain rises approximately 300 feet above the surrounding area and occupies about 900 acres. Although called a mountain, the top of this topographic feature is 400 to 500 feet lower than the summits of Sentinel, Square, and Bullion buttes, adjacent buttes in the area. Furthermore, it is less prominent on the horizon than these other buttes because it has half the relief of either Sentinel or Bullion buttes.


Blue Mountain covers approximately 300 acres and rises about 200 feet above the surrounding area. The eastern Devils Lake Basin is unique in that three "mountains" occur within a 15-mile radius of each other --Blue Mountain, Lookout Mountain, and Devils Lake Mountain. Both Lookout Mountain and Devils Lake Mountain rise approximately 120 feet above the countryside. Devils Lake Mountain extends over an area of about 1,600 acres, but Lookout Mountain occupies an area of only 40 acres. All three of these topographic highs are lower and less prominent than the major buttes of southwestern North Dakota. If they had been located in that part of the state, they may not have even rated a name, let alone a mountain designation. But everything is relative and, located where they are, they are prominent landmarks.


The Turtle Mountains rise some 700 feet above the surrounding plain and occupy about 10 townships or 360 square miles in northeastern Bottineau and northern Rolette counties. It is generally believed that native people applied this name because they thought the profile of the topographic feature resembled a turtle.


North Dakota's highest point a butte 

Curiously, the highest point in North Dakota occurs on a landform called a butte, not a mountain. The high point in the state is the summit of White Butte in Slope County at an elevation of 3,506 feet above sea level. That elevation places North Dakota above the high points of 20 other states. We also have the distinction of being the only state in the Union where the high point occurs on a butte. Most high points, 64 percent, occur on mountains, mounts, or peaks with an assortment occurring on hills, sauks, knobs, domes, crests, and mounds. White Butte is located six miles south of Amidon and three miles east of US Highway 85. Given that it is the highest point in the state, we could perhaps be forgiven had we instead named White Butte, White Mountain. Conversely, the lowest point in North Dakota occurs along the Red River Valley in eastern North Dakota at an elevation of 750 feet.


White Butte is one of three major buttes that exist in close proximity. These buttes are from west to east: Black, Chalky, and White. White Butte is tucked behind the Chalky Buttes which trend north to south and parallel US Highway 85 in the area. The Chalky Buttes rise 400 to 500 feet above the surrounding countryside while White Butte rises about 400 feet above the surrounding area. Although the view from the top of White Butte is nice, the view from the crest of Chalky Buttes is less impeded. Black Butte, not White Butte, is the most prominent of the three buttes and the view from the top of that butte is the most spectacular.


In her book on North Dakota beauty spots, Bertha Palmer noted that from Black Butte "one can see the 'end o' the world' in every direction except east where Chalky Buttes lie a few miles distant." Black Butte, originally known as HT Butte (named after the HT Ranch, a prominent horse ranch established in 1884 by the Little Missouri Horse Company), is located three miles west of the Chalky Buttes and rises approximately 550 feet above the surrounding area to a height of 3,465 feet. Because it is only 41 feet lower than White Butte and is more prominent, Black Butte was identified for a time as the highest point in North Dakota. Black Butte was still identified as the highest point in North Dakota when Palmer wrote her book in 1928.


The Killdeer Mountains are two mesas (North Killdeer Mountain and South Killdeer Mountain) that rise approximately 700 feet above the surrounding countryside in northern Dunn County, about six miles northwest of the town of Killdeer. The mesas cover an area of roughly 4,800 acres. The rocks of the Killdeer Mountains have been interpreted to have been deposited in a shallow lake about 25 million years ago. Some of the rocks contain volcanic ash that likely was transported into the area from volcanoes that were active in central Montana and northwestern Wyoming. The Killdeer Mountains are a classic example of what geologists call inverted topography. That is to say, 25 million years ago the area now represented by a topographic high was a topographic low or depression.


Erosion and glaciers create the heights 

Geologists in our agency are often asked if various buttes in southwestern North Dakota, (for example Bullion, West Rainy, Square, or Sentinel buttes) are old volcanoes similar to Mount Capulin (a cinder cone) in northeastern New Mexico that juts about 1,000 feet above the countryside. It is easy to see why people draw the parallel. Like Mount Capulin, the buttes in southwestern North Dakota often dominate the landscape. Rising between 400 and 700 feet above the surrounding countryside, these buttes are prominent landmarks on the horizon from a distance of 30 or more miles. However, these features are the not the products of explosive geologic processes from deep within the earth, but the result of erosive processes that have been at work for millions of years.


Therefore, the tops of these landmarks are a testament to the position of the surface of the surrounding countryside at one point in geologic time. These buttes have stood still, capped by rocks that are more resistant to erosion than the surrounding countryside, while the rocks around them were worn down to the present surface. You can stand near the base of the Killdeer Mountains and easily visualize how 700 feet of rock has been eroded from the surrounding countryside. It takes more imagination when standing on the dinosaur-bearing rocks of the Hell Creek Formation near Barren Butte, west of Fort Yates in Sioux County, to visualize a surface that at one time likely stood more than 1,500 feet above the present ground surface.


The topographic highs in eastern North Dakota generally were formed by a much different process than those in the western portion of the state. Rather than being remnants of rock that were formed by the erosive processes of wind, rain, and water, these landforms generally were created as a result of glacial processes. Many of these are ice-thrust features that formed when glaciers picked up blocks of material and then redeposited them a short distance away. These can occur as relatively isolated masses of sediment, such as Blue Mountain or in larger masses such as the Prophets Mountains. The Turtle Mountains are examples of erosional remnants similar to those topographic features in western North Dakota except that they were overridden by glaciers and the jagged edges characteristic of the buttes in southwestern North Dakota have been smoothed by the addition of glacial sediments.


Subtle but awesome

The geology of North Dakota is often very subtle when compared, for example, to the Rocky Mountain and Appalachian states. The "mountains" or buttes in the eastern part of our state are a prominent testament to the awesome power exerted by thousands of feet of ice that constituted the glaciers that ebbed and flowed across most of North Dakota.


The "mountains" and buttes in western North Dakota are equally impressive testaments to the power of wind and rain over an extremely long period of time. These latter processes may be immeasurable in a brief span of time, but because they are relentless, their power is equally impressive when measured in geologic time.


As the character, Red, says in the movie Shawshank Redemption, "Geology is the study of pressure and time. That's all it takes, really - pressure and time."


Ed Murphy, a Bismarck native, is State Geologist and Director of the North Dakota Geological Survey, a division of the North Dakota Department of Mineral Resources.

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