Nebraska, constituent state of the United States of America. It was admitted to the union as the 37th state on March 1, 1867. Nebraska is bounded by the state of South Dakota to the north, with the Missouri River making up about one-fourth of that boundary and the whole of Nebraska’s boundaries with the states of Iowa and Missouri to the east. The boundary with Kansas to the south was established when the two territories were created by the Kansas-Nebraska Act in 1854. In the southwestern part of the state, the boundary with Colorado forms a right angle (south and west), which creates Nebraska’s panhandle, to the west of which is the boundary with Wyoming. Lincoln, in the southeastern part of the state, is the capital.

As one of the west-central states of the United States, Nebraska was primarily a stopover point for those migrating to the rich trapping country to the north and west as well as to the settlement and mining frontiers of the mountain and Pacific regions during the first half of the 19th century. With the development of railroads after the American Civil War (1861–65) and the consequent immigration, the fertile soils of Nebraska were plowed, and its grasslands gave rise to a range cattle industry. As a result, the state has been a major food producer since statehood.

Rivers have been important to Nebraska’s geography and settlement. A majority of Nebraskans live close to the Missouri and Platte rivers, leaving much of the state lightly populated. The Missouri was a major highway to the trans-Mississippi West in the early 19th century. The Platte River has also played a significant role in Nebraska’s history. In fact, the state’s name is derived from the Oto Indian word Nebrathka (“Flat Water”), a reference to the Platte. Area 77,347 square miles (200,329 square km). Population (2020) 1,961,504; (2022 est.) 1,967,923.

Nebraska comprises parts of two of the United States’ principal physiographic regions—the till plains of the Central Lowland (in the eastern third of the state) and the Great Plains (which makes up the centre of the state).

The Sand Hills region of north-central and northwestern Nebraska is one of the state’s most distinctive features. Comprising nearly one-fourth of the area of the state, it consists of sloping hills and valleys varying from 25 to 400 feet (8 to 120 metres) in elevation. With many small lakes and luxuriant grasses, the Sand Hills area is a superb rangeland.

Elevation in Nebraska rises from a minimum of 840 feet (256 metres) above sea level in the southeast to a maximum of 5,426 feet (1,654 metres) near the Colorado and Wyoming boundaries. Much of the land is gently rolling prairie, although the river valleys, much of south-central Nebraska, and a large portion of the panhandle district are flatlands.

The Great Plains are the broad expanse of prairie and steppe that lie east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S. states of Colorado, New Mexico, Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Montana, and Wyoming, and the Canadian provinces of Alberta, Saskatchewan, and Manitoba.

The region covers almost 500 miles (800 km) east to west and 3,000 miles (4,800 km) north to south. Much of the region was home to Native American tribes and enormous bison herds until their decimation during the mid/late 1800s. Many areas of the Great Plains have become productive crop-growing areas due in part to extensive irrigation. While agriculture remains an important industry, it is no longer the major activity of most plains inhabitants. In the later half of the twentieth and twenty first centuries population has become more concentrated in urban areas. Employment is most often found largely in services, tourism, light manufacturing, construction, finance, insurance, and technology.

Between 570 and 70 million years ago, shallow seas covered the interior of North America, leaving behind 5,000 to 10,000 feet of layered sediment that eventually solidified into rock. The flat sea floor was created by slow uplift, and only the Black Hills experienced significant disturbance. The Rocky Mountains, however, were uplifted rapidly, causing sediment to be stripped from the mountain tops and deposited on the plains.

Soil erosion is the removal of soil from a position on the landscape. The two main agents of soil erosion are wind and water. The type of erosion that occurs is generally related to climate. Because the climate of the Great Plains is relatively dry, and strong winds are common, wind erosion is widespread throughout the region. On May 12, 1934, for example, winds carried an estimated 200 million tons of soil from the Southern Great Plains over 1,500 miles to the Atlantic Ocean. Ideal conditions for wind erosion are loose, finely divided and dry soil on a bare, smooth surface.

Wind erosion moves soil in three ways: suspension, saltation, and surface creep. Very fine particles (less than 0.05 mm in diameter) can be blown into the air and carried in suspension for long distances. The particles fall out of suspension when the wind velocity is reduced or they are washed out by rain. Soil grains between 0.05 mm and 0.5 mm in diameter are too heavy to be suspended. These grains are lifted briefly in the air, move a short distance, and fall back to the surface. Most soil eroded by wind moves by this type of motion (saltation). Saltating grains generally bounce along the surface of the soil until the wind velocity lessens or they meet some obstruction. These grains may knock other grains into the air. Soil grains between 0.5 mm and 1 mm in diameter are too large to be lifted into the wind stream. They are bumped along the soil surface by saltating grains in a movement called surface creep. Soil grains moving by saltation are the keys to wind erosion. Saltating grains increase the number of smaller and larger particles that move in suspension or by soil creep.

Water erosion is more prominent in humid regions. It does, however, occur in the Great Plains especially on sloping landscapes. In 1992 the average annual water erosion rate on cropland was estimated at 3.1 tons per acre. The movement of soil by water is a complex process that is influenced by the amount, duration, and intensity of rainfall, as well as by the nature of the soil, ground cover, and slope of the land. Raindrops play a substantial part in the movement of soil by water. Soil grains are detached from the soil mass by the force of raindrops striking the soil grains. The soil grains may then be splashed, rolled, slid, or carried in suspension along the land surface.

Data Source: ArcGIS Online Gallery, Nebraska Highway Data, Interactive Map Source github | Cartographers: Dong Gai (dgai@wisc.edu), Yutong Jiang (jiang282@wisc.edu)