The mighty metamorphosis which, in the space of five years, came over the country at the headwaters of the Missouri, produced an equally marvelous change in the commercial business of that stream. The river gave a sure highway for travel to within one hundred to two hundred miles of the mines. There was no other route that could compete with it, for this could carry freight from St. Louis to Fort Benton, in cargoes of one to five hundred tons, without breaking bulk. The emigrants themselves went in large numbers by overland routes, but a great number also by the boats; while nearly all merchandise, including every necessary of life, and all mining machinery and heavy freight, came by the river. [Sidenote: HIGH WATER MARK.] [Sidenote: AN EXTRAORDINARY SCENE.] The steamboat trade jumped suddenly to enormous proportions. Prior to 1864 there had been only six steamboat arrivals at the levee of Fort Benton. In 1866 and 1867 there were seventy arrivals. The trade touched high-water mark in 1867, and at this time presented one of the most extraordinary developments known to the history of commerce. There were times when thirty or forty steamboats were on the river between Fort Benton and the mouth of the Yellowstone,[48] where all the way the river flowed amid scenes of wildness that were in the strictest sense primeval. To one who could have been set down in the unbroken wilderness along the banks of the river, where nothing dwelt except wild animals and wilder men, where the fierce Indian made life a constant peril, where no civilized habitation greeted the eye, it would have seemed marvelous and wholly inexplicable to find this river filled with noble craft, as beautiful as any that ever rode the ocean, stored with all the necessaries of civilization, and crowded with passengers as cultured, refined, and well dressed as the cabin list of an ocean steamer. What could it all mean? Whence came this handful of civilization and what brought it here? Certainly a most extraordinary scene, flashed for a moment before the world and then withdrawn forever. [Sidenote: PERILOUS VOYAGE.]