During its long course from the far away Rockies to its junction with the mighty Mississippi, the Missouri River penetrates every variety of country one can think of. In many places it passes through vast stretches of prairie land, where, as far as the eye can reach, the country is like a billowy sea, being covered with grass. Then again it cuts a channel between rocks that form rapids quite as dangerous as those of the Upper Nile, and known as the Cataracts. There are banks that are heavily timbered; and even low places, swampy, and almost impossible of navigation for canoes. Much difficulty is encountered in avoiding the islands that crop up, some covered only with rank water grass, others bearing a luxuriant growth of trees, such as sycamore, cottonwood, walnut, and others. Sand-bars form and disappear daily, so that a pilot never knows what he has before him in trying to take a boat along this erratic stream. And it was up this swift current that the daring explorers, led by Lewis and Clark, ventured to push their three boats, day after day, as the summer months glided on, facing perils of every description, and bent on carrying out the plans which the President himself had personally approved, if indeed the entire scheme was not of his own conception. NOTE 4 (PAGE 160) Well might Roger say this, for at that day, and much later also, it was no uncommon thing for a ranger on the prairie to see, from some butte, a drove of bison rolling by that seemed to stretch from horizon to horizon, and take hours in passing. The Indians said they were as many as the grains of sand on some of the bars that could be found along the erratic course of the great Missouri River. They hunted them in and out of season, and killed tens of thousands, no doubt, every year, often driving an entire herd over some precipice for the sake of securing the tongues alone, which were esteemed a great delicacy. But up to the introduction of the repeating firearm, at about the time the Central Pacific Railroad was being put through, there seemed no perceptible diminution to the vast number of the shaggy beasts. But civilization came and finished the business; and at the present time, save for a few scattered specimens, in small droves, numbering some hundreds in all, the once famous bison, called wrongly the buffalo, has been entirely exterminated. NOTE 5 (PAGE 274)