The fact that the Missouri River is longer than the entire Mississippi, and more than twice as long as that portion of the latter stream above the mouth of the Missouri, has led to the frequent observation that the name which applies to the lower course of the Mississippi should apply also to the tributary. But this would evidently not be a fitting nomenclature. The Mississippi is the trunk stream, receiving the drainage from the Alleghenies on the east and the Rockies on the west. It divides the continent into approximately symmetrical portions. This division has entered into the very life of our national development, and is so natural and convenient that the stream itself from north to south is appropriately known by a single name. The Missouri is the great tributary from the mountains on the west, as the Ohio is from the mountains on the east. The characteristics of the Missouri are so peculiarly its own that a separate name is more befitting than one divided between itself and another and very different stream. [Sidenote: EARLY EXPLORATION.] During the eighteenth century the French gradually extended their knowledge of the river. It is not likely that the voyageurs had ascended as far as to the Mandan villages, a short distance above the modern capital of North Dakota, when, in 1738–43, De la Verendrye crossed over from the north and struck the river at that point. But it is quite certain that at the time of the founding of St. Louis, 1764, the river was well known for a thousand miles above its mouth. From that time knowledge of it increased more rapidly, and when Lewis and Clark went up the river in 1804, they found that white men had preceded them almost to the mouth of the Yellowstone. CHAPTER IX. KINDS OF BOATS USED ON THE MISSOURI. [Sidenote: RIVER BOATS.]