"The Yellow Stone is navigable for several hundred miles from its mouth, penetrating the heart of the agricultural and mineral regions of Eastern Montana.... The section is undulating, with ranges of mountains, clad with evergreens, between which are beautiful valleys and winding streams, where towns and cities will spring up to adorn these mountain retreats, and give room for expanding civilization.... "On the east side of the mountains the mines are rich beyond calculation, the yield thus far having equalled the most productive locality of California of equal extent. The Bannock or Grasshopper mines were discovered in July, 1862, and are situated on Grasshopper Creek, which is a tributary of the Jefferson fork of the Missouri. The mining district here extends five miles down the creek, from Bannock City, which is situated at the head of the gulch, while upon either side of the creek the mountains are intersected with gold-bearing quartz lodes, many of which have been found to be very rich.... "While gold has been found in paying quantities all along the Rocky chain, its deposits are not confined to this locality, but sweep across the country eastward some hundreds of miles, to the Big Horn Mountains. The gold discoveries there cover a large area of country."[G] Governor Stevens says: "Voyagers travel all winter from Lake Superior to the Missouri, with horses and sleds, having to make their own roads, and are not deterred by snows." Alexander Culbertson, the great voyager and trader of the Upper Missouri, who, for the last twenty years, has made frequent trips from St. Louis to Fort Benton, has never found the snow drifted enough to interfere with travelling. The average depth is twelve inches, and frequently it does not exceed six.[H] Through such a country, east of the mountains, lies the shortest line of railway between the Atlantic and Pacific,--a country rich in mineral wealth, of fertile soil, mild climate, verdant valleys, timbered hills, arable lands yielding grains and grass, with mountain streams for the turning of mill-wheels, rich coal beds, and springs of petroleum! THE MOUNTAINS. There are several passes at the head-waters of the Missouri which may be used;--the Hell-Gate Pass; the Deer Lodge; and the Wisdom River, or Big Hole, as it is sometimes called, which leads into the valley of the Bitter Root, or St. Mary's. The Big Hole is thus described by Lieutenant Mullan:-- "The descent towards the Missouri side is very gradual; so much so, that, were it not for the direction taken by the waters, it might be considered an almost level prairie country."[I] Governor Stevens thus speaks of the valley of the Bitter Root:--