TOPOGRAPHY. The eastern part of the State is the perfectly level bed of the ancient Lake Agassiz, now' traversed by the Red River and its tributaries. It lies about 1000 feet above sea level, and merges westward into the rolling prairies of the central region. In the north the land rises to a height of over 2000 feet in the small forest-covered plateau known as the Turtle Mountains. This range extends about 20 miles south of the boundary. Southwest ward the prairies rise toward the grassy Plateau du Coteau (hi Missouri, which has an elevation of 2000 feet near the centre of the State, and rises gradually to 3000 feet in the extreme southwestern corner. There are no great alti tudes above the general level. In the central region there are rounded, grassy, and boulder crowned hills of glacial drift ; and in the south west isolated conic-al buttes capped with sand stone become more and more frequent until the rough and rocky 'bad lands' of the southwestern corner arc reached.
The principal rivers lie from 100 to 300 feet below• the surronmling plains, and are lined with bhilTs. The western half of the State is traversed in a winding. southeast course by the Missouri
River, which enters on the western boundary and leaves the State near the middle of the southern boundary. Its chief tributaries from the State are from the right and drain the southwestern plateau. They are the Little Missouri, Knife, Heart, and Cannon Bali rivers. The Yellowstone also joins the Missouri in North Dakota imme diately east of the Montana boundary line. The northern portion is drained by the Souris o• Souse River, which flows southeast from Canada and re enters that country in the opposite direction after making a long narrow loop toward the centre of the State. From this central section the James Rive• flows southward into South Dakota, where it joins the Missouri. The remaining eastern portion is drained by the Red River of the North, chief of whose numerous tributaries is the Shey enne. Scattered over the central and eastern plains are numerous the largest of which is Devil's Lake, an irregular body of water 32 miles long and 1 to 5 miles wide, with wooded shores.