NEBRASKA, a central State of the American Union, lies between 40º and 43º N. lat.; the Missouri flows along its eastern side, the most easterly point being 95º 25' W. long., and the boundary line separating it from Wyoming on the west is 104º W. long. It is bounded on the S. by Colorado and Kansas, on the E. by Missouri and Iowa, on the N. by Dakota, and on the W. by Wyoming and Colorado. The width of the State from north to south is 208½ miles, the length from east to west 413 miles, and the area 76,647 square miles, or 49,054,080 acres.
The greater part of Nebraska is a plateau. The lowest
point is at the mouth of the Nemaha, in the south-eastern
part of the State, where the elevation is 880 feet; the
highest spot is Scott's Bluffs, in the extreme western part
of the State (6000 feet). The eastern half of the State
has an average elevation of 1400 feet; and the whole State
averages 2312 feet above the sea.
There are no mountains, but in the northern and
western parts there are some ridges and a few lofty hills. Generally the slopes are gentle, but occasionally precipitous, and in rare cases there are cañons with perpendicular sides. The lands of three-fourths of the State are gently rolling. The surface owes its present form mainly to erosion. Between all the forms of upland surface the transition is gradual. The bottom lands and valleys are the most conspicuous modifying features of the surface. They are huge shallow troughs, varying in breadth from a quarter of a mile on the smaller streams to 23 miles on the Platte and the Missouri. Their numerous terraces, like broad steps, gradually lead to the bordering uplands, which in turn are varied in height and form. Occasionally it is hard to determine where the bottom ends and the bordering bluffs begin, but generally both forms are clearly outlined. The innumerable tributaries that creep quietly into the main bottoms greatly complicate and beautify the forms of landscape. The number of these valleys is very great, the Republican alone having more than four hundred tributaries. Not less than 25 per cent. of the entire surface of the State is composed of well-watered valleys. The few destitute of water are regaining the streamlets of former times through the climatic changes brought on by the settlement of the State. Most of these bottom lands, though composed of the richest vegetable mould and alluvium modified by loess materials, are perfectly dry, and rarely subject to overflow. A clear conception of the topography can only be obtained by crossing the State at right angles to the courses of the valleys. The rolling lands bordering the valleys gradually disappear as the divide is approached which separates one drainage system from the next. Here the land swells out into a gently undulating plain that varies in extent from 1 to 30 miles. Some of these higher uplands have a great number of shallow basin-like depressions where soil and grasses closely resemble those of the bottom lands. They are the sites of small lakes that recently existed here, and some of them still retain this character, being filled with fresh water from 1 to 15 feet in depth. South of the valley of the Niobrara, and commencing in 100º W. long., are the noted sand-hills. They vary in height from a few yards to several hundred feet. Almost every form of wind sculpturing is found, but the conical predominates. Though formerly naked, these hills have recently become covered with grasses which are fixing the sands, and preserving
their curious crater-like forms. They extend to the head
of the forks of the Loup river, covering an estimated area
of 8000 square miles.