portion of Illinois known as the military bounty tract, situated in the northern part of the State, is extracted from a volume called “Illinois in 1837." As it is applicable to all the valley of the Upper Missisippi, with very slight variations, a very accurate idea may be derived from it of the structure of any portion of that country. In Iowa generally the vegetable mould at the top is a little thicker than it is here stated:

"A scientific gentleman who has recently examined the central parts of the Military Bounty Tract, has given the following as the geological structure of the upland prairies in that region. That the same general structure prevails throughout the entire peninsula (between the Illinois and Missisippi Rivers), and all the central and northern parts of the State, is most probable. 1st. Vegetable mould, formed by the decomposition of grass upon the original clay soil, eight to thirty inches: 2d, pure yellow clay, three to eight feet 3d, gravelly clay, mixed with pebbles, four to ten feet: 5th, limestone rock, two to twelve feet: 5th, shale, covering a stratum of bituminous coal, generally four to five feet thick: 6th, soapstone; then sandstone. The bed of limestone seems to be universal in this region, it having been discovered in all the wells that have been dug, and in all the banks of water-courses of any magnitude."

Although no part of this region can with propriety be, denominated hilly, yet upon the Wisconsin, Fox, the head waters of Rock and Milwaukie Rivers, the country is considerably diversified with hills, or rather swells, and valleys. The only hills worthy of particular notice, not only in this vicinity, but in the whole section under consideration, are the Ocooch and Smoky Mountains, which are broad and elevated ridges rather than mountains. The former is situated about twelve miles north of the Wisconsin, one hundred miles above its mouth; and the latter about forty miles south of the portage

between the river just mentioned and Fox River of Green Bay. (Long's Expedition, v. ii., p. 335.) The blue mounds, near the Wisconsin; the Platte mounds, near Platteville; the Pilot-knob, near Galena; the Table mound, three miles south of Dubuque; Sherald's mound and Pike's mountain, may also be named among the lesser elevations of this region, as also Sinsinewa mound. There are some elevations also near the right bank of the Missisippi, above Lake Pepin; and, in fact, on both sides in that part of the country. The Coteau des Prairies is an extensive and elevated tableland, dividing the waters which flow into the Missouri from those falling into the St. Peter's and Missisippi. A range of highlands extends from the Ocooch, on the Wisconsin, to Lake Superior, supposed by Long and Dr. James to be a continuation of the Ozark mountains. The northern section of this highland usually goes under the name of Porcupine Hills.

"It is neither a mountainous, nor a hilly, nor an absolutely flat country," says Nicollet, "exhibiting undulations of the surface that are not entitled to these usual appellations. There are hillocks, swells and uplands, but they have a longitudinal and horizontal rather than a vertical projection. In other words, it is a beautiful arrangement of upland and lowland plains, that give it an aspect sui generis. The first Frenchmen who explored it, and the British and Americans who followed them, were so forcibly impressed with this novelty in the appearance of the topography, that they employed new names to designate it. Hence we have the expressions coteau des prairies, coteau des bois [highland prairie, highland woods], hauteur des terres [summit of land], and rolling, flat, or marshy prairies. There is still sufficient variety in the irregularities of its surface, and the distribution

of the water-courses, woodlands and prairies, to bestow interest and value upon its several sub-divisions.

"The basin of the Upper Missisippi is separated, in a great part of its extent, from that of the Missouri, by an elevated plain, the appearance of which, seen from the valley of the St. Peter's, or that of the Rivière Jacques, looming, as it were, a distant shore, has suggested for it the name of coteau des prairies. Its more appropriate designation would be that of plateau, which means something more than is conveyed to the mind by the expression, a plain.

"Its northern extremity is in lat. 46°, extending to 43°; after which it loses its distinctive elevation above the surrounding plains, and passes into rolling prairies. Its length is about two hundred miles, and its general direction N.NW. and S.SE. Its northern termination (called 'tête du coteau, in consequence of its peculiar configuration) is not more than fifteen to twenty miles across; its elevation above the level of the Big Stone Lake is 890 feet; and above the ocean 1,916 feet. Starting from this extremity (that is, the head of the coteau), the surface of the plateau is undulating, forming many dividing ridges, which separate the waters flowing into the St. Peter's and the Missisippi from those of the Missouri.

"Under the forty-fourth degree of latitude the breadth of the coteau is about forty miles, and its mean elevation is here reduced to 1,450 feet above the sea. Within this space its two slopes are rather abrupt, crowned with verdure, and scolloped by deep ravines thickly shaded with bushes, forming the beds of rivulets that water the subjacent plains. The coteau itself is isolated in the midst of boundless and fertile prairies, extending to the west, to the north, and into the valley of the St. Peter's.

"The plain, at its northern extremity, is a most beautiful

tract of land, diversified by hills, dales, woodland and lakes: the latter abounding in fish. The region of country is probably the most elevated between the Gulf of Mexico and Hudson's Bay. From its summit, proceeding from its western to its eastern limits, grand views are afforded. At its eastern border, particularly, the prospect is magnificent beyond description, extending over the immense green turf that forms the basin of the Red River of the North, the forest-capped summits of the hauteurs des terres that surround the sources of the Missisippi, the granite valley of the Upper St. Peter's, and the depressions in which are Lake Travers and the Big Stone Lake.

"The other portions of the coteau, ascending from the lower latitudes, present pretty much the same characters. This difference, however, is remarkable: that the woodlands become scarcer, whilst the open prairies increase in extent. It is very rarely only that groves are met with, to which the N'dacotahs, or Sioux, have given the name of Tchan Witah, or Wood Islands. When these groves are surrounded by water, they assume some resemblance to oases, and hence I have assigned this name to some of them on my map.

"These oases, possessed of a good soil, well wooded, offering an abundance of game, and waters teeming with fish, offer inducements for permanent settlements. In this region there are frequent instances of a marsh or lake furnishing waters to different hydrographical basins,—a fact observed by the Sioux, and which they express in the compound word of their dialect, mini-akipan-kaduza;*—from mini, water; akipan, division, share; and kaduza, to flow, to run out." [Nicollet, pp. 7, 8, 9, 10.]

* Mr. Nicollet seems to mistake the application of the phrase miniakipan-haduza. Akipan is probably a ridge of land, or, as the white settler calls it, in the very word of the Indians, a divide. The phrase is pro

The country from Platte River to Council Bluffs is thus described by Nicollet [p. 39, et seq.]:

"It will be recollected that I have represented the whole bed of clay, divided into two portions by a band of ironstone, as having a nearly uniform thickness of 200 feet, and that it is intermixed with lumps of gypsum and limestone, together with nodules of pyrites; so that a soil, produced from such materials, could hardly be expected to throw up anything but a meagre vegetation. It is of a character, too, to be so acted upon by atmospheric agents, as to exhibit, by the wear and tear of its superficial portions, every variety of fanciful summits-domes, cupolas, towers, colonnades, &c.; imparting to it a remarkably picturesque appearance, especially when contrasted with the dense vegetation that borders the river, and a narrow slip of prairies crowning the summits of the hills that are seen to extend themselves on either side.

"The same physical causes, under other circumstances, produce new effects, that add to the beauty and grandeur of the scenery. Thus, the rains furrow and cut through the plastic and seleniferous clay, down to the most resisting limestone, giving rise to a sort of advancing platform, with a perpendicular elevation of from 30 to 40 feet, resembling a succession of long lines of parapets.

"But I have now reached the proper place to treat of a very interesting phenomenon observed in the midst of this cretaceous group. It manifests itself by the occasional appearance of a dense smoke at the top of some conical hill, or along a line of country bounded by the horizon, so

bably applied to a ridge, and not to a marsh. So Nicollet has himself applied it on his map to the ridge separating the waters of St. Peter's from those of the Missisippi.