The valley is bounded on the west by the Rocky Mountains, on the east and south-east by the Alleghanies, and on the south by the Gulf of Mexico. To the northward, no precise limits can be assigned as its boundary. Although many have supposed that the waters of the Mississippi are separated from those running north-westwardly into the Pacific Ocean, and north-eastwardly into the Atlantic, by a mountainous range of country, yet, from the best information that can be had on the subject, the fact is quite otherwise. The old and almost forgotten statement of savage origin, viz. that "four of the largest rivers on the continent have their sources in the same plain," is entitled to far more {262} credit. The rivers alluded to are the Mississippi, the St. Lawrence, the Saskashawin, and the Oregon or M'Kenzie's river. Agreeably to the accounts of Colonel Dixon and others who have traversed the country situated between the Missouri and the Assinaboin, a branch of Red river of Hudson's Bay, no elevated ridge is to be met with; but, on the contrary, tributaries to both these streams take their rise in the same champaign, and wind their way in various directions to their far distant estuaries. Judging from the maps that have been given of the country near the sources of the Mississippi, and of the region generally situated northwardly of the great lakes, as also from the accounts of various travellers who have penetrated many parts of those countries, the same remarks appear equally applicable to a large portion of the whole. The watercourses are represented as chains of lakes of various magnitudes, while lakes and stagnant pools are scattered in almost every direction, without ridges or perceptible declivities to show the direction in which they are drained. But we forbear to enlarge on this subject, and beg leave that reference may be had to Bouchette's map of the region of which we have just been treating, as a document containing ample illustrations of our opinion. Hence it will be inferred that the valley of the Mississippi is merely a portion of an immense region of valley or flat country, extending from the Gulf of Mexico north-eastwardly to the Atlantic, and north-westwardly to the Pacific Ocean.