North Dakota: A Guide to the Northern Prairie State

by Federal Writers' Project of the Works Progress Administration for the State of North Dakota

NORTH DAKOTA: ITS NATURAL SETTING

North Dakota is a rectangular area of 70,837 square miles, lying in what the United States Geological Survey has designated the center of the North American Continent. It is approximately 1,500 miles from the Atlantic, the Pacific, the Gulf of Mexico, and the Arctic Archipelago of North America. North to south it extends 210 miles, and east to west an average of 335 miles. On the north are the Provinces of Manitoba and Saskatchewan, Canada; on the east, the Red River of the North and the Bois de Sioux form the boundary between this State and Minnesota; on the south is South Dakota and on the west, Montana.

THE SURFACE OF THE LAND

The land surface resembles three broad steps of prairie, rising a half-mile in altitude from the eastern to the western boundary. The first two steps lie in the Central Lowlands of the Interior Plains, the third in the Great Plains area.

The lowest step is the fertile, floor-like Red River Valley, once the bed of glacial Lake Agassiz. Near the Canadian boundary the valley is about 40 miles wide, but it gradually narrows until near the South Dakota line it is only 10 miles in width. With its northward slope of only about one foot to the mile, an even more gradual eastward slope, and few prominent surface features, the land offers no obstacles to a view across miles of level checkerboard fields. Natural woods grow along the Red River and its winding sluggish tributaries, and farmyard groves dot the landscape.

The Pembina Escarpment, a rise of 300 to 400 feet along the western edge of the valley, defines the beginning of the central surface-step, the Drift Prairie, or Drift Plain. At the northern end of the escarpment, which is a continuation of the Manitoba Escarpment in Canada, lie the wooded Pembina Mountains, jutting sharply above the valley floor. South of these hills the rise is less pronounced except at the southern end, where the hills again become prominent to merge with the Coteau des Prairies, an escarpment lying chiefly in South Dakota.

Glacial deposits, or drift, of finely ground rock, sand, and gravel give the Drift Prairie its name. It is a rolling, fertile plain, varying from 70 to 200 miles in width, and broken by low ridges of hills, shallow coulees, and numerous small lakes. To the northwest lies the Souris River Valley, a small glacial lake bed resembling the Red River Valley. Devils Lake, largest in the State, lies in the northern part of the Drift Prairie, and together with Stump Lake forms the basis of the interior drainage system; near its southern end are the headwaters of the James and Sheyenne Rivers, both flowing southward, the James into the Missouri and the Sheyenne into the Red.

The Missouri Escarpment, rising 300 to 400 feet above the Drift Prairie and cutting across the State diagonally in a northwest-southeast direction, marks the rise of the third surface-step, the Missouri Plateau, which extends west to the Rocky Mountains. Lying along the top of the plateau, in some places not far from the escarpment and at other points 50 miles west of it, is the Altamont Moraine, a belt of rough, stony hills, indicating the farthest advance of the Dakota lobe of the Wisconsin ice sheet. In the north this moraine is a part of the Height of Land forming the watershed between the north-and south-flowing streams of the continent.

Between the escarpment and the Missouri River the plateau is known as the Couteau du Missouri. West of the river it is known locally as the Missouri Slope. The surface of the plateau, typical of the Great Plains, is irregular and rolling, dotted with old lake beds—some of which contain large deposits of sodium sulphate—and underlain with vast lignite beds and valuable clay and bentonite deposits.

In the Missouri Slope is the most unusual area in the State—the Badlands of the Little Missouri. Here erosion has formed, and continues to form, a fantastic array of buttes in which layers of brick-red scoria and gray, blue, and yellow clays are vividly exposed. Abrupt buttes and mesas characterize the landscape, increasing in size and number toward the southwest corner of the State. Among them is Black Butte, 3,468 feet above sea level, the highest point in North Dakota.

CLIMATE

Absence of great variation in physiography gives all portions of the State an almost uniform climate. North Dakota is situated in a temperate region of moderate rainfall, and owing to its position in the center of the North American Interior Plains it has a typically continental climate.

One of the characteristics of such a climate is a wide range of temperature, and to this the State can make good claim. North Dakota has a recorded range from 124° F., registered September 3, 1912 at Medora, to -60° F., recorded February 15, 1936 at Parshall. These temperatures are, of course, unusual, but the mercury often reaches 100° F. during the summer, whereas 30° to 40° F. below zero is not uncommon in winter. The mean temperature for the months of June, July, and August is 65.7° F., and for December, January, and February, 9.7° F. Relatively low humidity, averaging 68 percent, makes these extremes less uncomfortable, however, than if the atmosphere contained more moisture.

The sections of the State vary more in the matter of precipitation than in any other climatic phase. The average is about 18 inches annually, ranging from about 22 inches in the southeastern corner to about 14 inches in the southwestern corner. Most of the precipitation occurs in the late spring and summer. During the period of 1925-34, three years had a rainfall in excess of normal, and seven were deficient in precipitation.

Long and severe winters are typical of this region. Nevertheless the summers, though comparatively short, are favorable for agriculture, owing to the long hours of sunshine. At the maximum, about June 21, there are as many as 16 hours of sunlight a day; and this, together with cloudless skies, contributes to the rapid growth and early maturity of crops.

HOW THE LAND WAS FORMED

The surface of North Dakota, comparatively unvaried, is no more simple than the geological pattern that lies beneath it. Deposited by the seas of three geologic ages, horizontal layers of rock top each other in methodical and unintricate succession.

In far-off Paleozoic times, when all creatures of the earth were invertebrates, strange shellfish, unlike any existing today, lived among the rich foliage at the bottom of the shallow sea that covered this region. Hundreds of varieties of fossil plants and shells are embedded in the sandstone, limestone, and shale which the sea deposited on the uneven surface of the then-existent crystalline rocks. These Paleozoic rocks have been encountered in deep wells in eastern North Dakota, although nowhere in the State are they found at the surface.

Toward the close of the Paleozoic era, changing climatic conditions caused the death of many forms of life upon the earth, and the development of new and hardier types. With these, in the Mesozoic era, came the new lords of the earth, the reptiles. Much of the globe from the Arctic Ocean to New Mexico was covered by a great sea on whose swampy shores huge dinosaurs, alligators, and crocodiles made their homes. Largest of these grotesque creatures was the brontosaurus, with his long snakelike neck and face and huge body. Struggling with him for supremacy of the swamps was the armored stegosaurus, whose row of vertical plates along his backbone from head to tip of tail made him a formidable enemy. Among the plant and animal life that throve on the sea bottom were shellfish three feet or more in diameter.

The earliest seas of the Mesozoic era deposited the Dakota sandstone that underlies all of the State except the Red River Valley. It is a soft white or gray stone, containing many marine fossils. Although it does not appear at the surface anywhere in the State, it has been studied from specimens obtained from deep wells here or from outcroppings in other States.

Many rivers flowing into the prehistoric seas brought mud and clay to mix with the soils of the sea bottom, forming the shales that today underlie most of the Great Plains, including North Dakota. The lowest of these, Benton shale, is dark gray, almost jet black in places, and contains bits of pyrite (fool's gold) and gypsum. Over it lies the bluish-gray Niobrara shale, in which natural cement is found. In the Pembina Mountains and the Sheyenne Valley, where these rocks appear at the surface, they have yielded shells of lamellibranchs (ancestors of today's clams and oysters) and bones of great sharklike fish. Over these two strata lies the Pierre shale deposit, dark bluish-gray in color. It is frequently seen in the valleys of streams east of the Missouri Plateau, but outcrops in only two places west of the Missouri Escarpment—where the Missouri leaves the State, and in the valley of the Little Beaver Creek in southwestern North Dakota. In it have been found fossils of the chambered nautilus, the oyster, and other marine animals, the crocodile, and the plesiosaur—that ungainly reptile which had "the body of a turtle strung on a snake."

Once again the sea covered the State and left the rust-colored Fox Hills sandstone, which is particularly conspicuous along the Cannonball River where action of underground water has formed it into the rusty-looking spheres which give the river its name. Similarly formed cylinders of this sandstone in concretionary form are also found along the stream, and large cylinders protrude from the top of Cannon Butte in the Badlands like the barrels of cannon from the turret of a huge battleship.

Near the close of the Mesozoic era, the climate of North Dakota became warmer, almost like that of the South Atlantic States. Through the swamps roamed horned carnivorous dinosaurs, especially triceratops, which had "the largest head with the smallest brain of the reptile race."

Again and again the sea invaded this swampland, depositing the Lance formation, comprising layers of massive sandstone and shale in which the luxuriant plant life of the area created thin beds of lignite coal. The Lance formation underlies most of the Missouri Plateau, and comes to the surface in two places—in the vicinity of Bismarck, and near Marmarth. Reptilian fossils are found in both the lignite and the intervening layers of rock.

At the dawn of the Cenozoic age, as mammalian life began to develop on the globe, another invasion of the sea left behind it a great plateau interspersed with swamps, marshlands, rivers, and lakes. On the plain grew giant sequoia, cypress, juniper, and other semitropical trees. Over the thick mat of mosses, lichens, and liverwort in the swamps crept turtles, alligators, lizards, and other reptiles, monstrous in size. King of this jungle was the titanothere, with its great body, short stocky neck, and columnar legs. Long-jawed shaggy mastodons and gigantic rhinoceroses challenged its supremacy. As these titans of the forest lumbered through the underbrush, herds of Merycoidodon culbertsoni or ruminating hogs, Leptomeryx evansi, dainty deerlike creatures no larger than jack rabbits, and little three-toed horses scampered out of their way.

The Fort Union formation, created through successive fresh water deposits of sediment in the swamps, contained vast quantities of rank swamp vegetation. In the intervening millions of years this has been turned into lignite, a very soft coal which has become North Dakota's most valuable mineral resource. The lignite veins in the formation indicate that the sea covered this area at least eleven times during the period when the formation was being deposited. In addition to lignite, the Fort Union clay shales and sandstones contain pure plastic clay beds and some bentonite, a claylike mineral of commercial value.

The recession of the seas left a broad and gently rolling plain cut by sluggish rivers whose wooded valleys were inhabited by the descendants of the great swamp beasts. When the waters again invaded the plain, the bones of these monsters were embedded in the deposits which became the White River formation, youngest bedrock underlying the State. So numerous are the fossil remains in the lower White River beds that these strata are called the titanothere beds. Fossils are found throughout the formation, however, ranging from mammal bones to the remains of fish and turtles. Erosion has worn away much of the White River formation in North Dakota, but it is conspicuously revealed on the summits of White or Chalky Butte, Sentinel Butte, Black Butte, and the Killdeer Mountains, and also in a few other small isolated areas in the Missouri Slope.

Gradually, during the time these formations were being laid down, the winters of this region were becoming more and more severe. Masses of ice moved slowly southward from the Arctic Region, covering much of the land and transforming the nearby forests, meadows, and swamps into a treeless plain of black mucky soil with a permanently frozen subsoil overgrown with moss, lichens, and dwarf shrubs. Fierce wintry storms took their toll of the mammoths, rhinoceroses, and reindeer living upon the tundras.

As the glaciers moved south, the animals were forced to flee to warmer lands. Soon the ice mass had covered all of North Dakota except a very small region in the southwest corner beyond the Killdeer Mountains. When at length it receded, it left in its wake boulders, gravel, and till—a drift soil composed of clay, sand, gravel, and boulders. Much of this now has been worn away; on the west side of the Missouri only a few scattered areas remain, and on the east side the till, though more continuous, is often merely a veneer a few feet in thickness.

The early glacier was followed by the Wisconsin ice sheet, the Dakota lobe of which covered a large part of this State, pushing back the Missouri River, which had previously flowed north into Hudson Bay, into its present channel.

Eventually this glacier, too, melted and receded, leaving a great lake about 650 feet deep, nearly 700 miles long, and 200 miles wide, with an area of not less than 110,000 square miles, including the region now known as the Red River Valley. This lake has been named Lake Agassiz, in honor of Louis Agassiz, first prominent advocate of the theory that drift was formed by land ice. Lake Agassiz existed some 10,000 years ago, lasted for probably 1,000 years, and covered an area greater than the present Great Lakes. Its sole remnants today are Lakes Winnipeg, Winnipegosis, and Manitoba, and Lake of the Woods.

Productive soil and ground water, closely allied resources, are North Dakota's greatest assets. The Wisconsin glacier and Lake Agassiz are largely responsible for the fertile soils that cover three-fifths of the State's surface. Through the Red River Valley the lake left a fine claylike silt 20 to 30 feet deep. The successive shore lines of the lake, showing its gradual recession, can be plainly seen in the ridges of sand and gravel that rise 10 to 25 feet along the western edge of the valley. Also on the west border of the valley are three extensive sand plains, the deltas of the Pembina, Sheyenne, and Elk Rivers, formed by glacial debris mingled with river silt. The Souris glacial lake bed, in the loop of the present Souris River, resembles the Red River Valley in geological history, but covers a much smaller area.

Immediately under the silt of the old lake beds and on the surface of the Drift Prairie is glacial drift or till. In much of the southwestern part of the State, particularly along the western tributaries of the Missouri, there are no glacial deposits; the topsoil is composed largely of shale and sandstone, and, though not so fertile as the old lake beds and glacial plains to the east, provides fine range country.