the advance guard of those many expeditions which followed and whose labours form the fourth division of our subject.  Fremont is the name, since that time called “Pathfinder,” though, of course, the paths he followed had often before been travelled by the redoubtable trapper, whose knowledge, like that of the native, was personal only.  Indeed, he was guided in his journeys by several men now quite as famous as himself—­Kit Carson, Fitzpatrick, Walker, and Godey.  But the field was still new to the world and to science.  Quite appropriately, one of the highest peaks from which the Colorado draws its first waters, is now distinguished by the name of the earliest scientific observer to enter its basin.  Fremont came up the North Platte and the Sweetwater branch, crossing (1842) from that stream by the South Pass thirty-four years after Andrew Henry had first traversed it, over to the headwaters of the Colorado.  The ascent to South Pass is very gradual, and there is no gorge or defile.  The total width is about twenty miles.  A day or two later Fremont climbed out of the valley on the flank of the Wind River Mountains.  “We had reached a very elevated point,” he says; “and in the valley below and among the hills were a number of lakes at different levels; some two or three hundred feet above others, with which they communicated by foaming torrents.  Even to our great height the roar of the cataracts came up, and we could see them leaping down in lines of snowy foam.”  Thus are the rills and the rivulets from the summits collected in these beautiful alpine lakes to give birth to the Colorado in white cascades, typical, at the very fountainhead, of the turbulence of the waters which have rent for themselves a trough of rock to the gulf.* Springing from these clear pools and seething falls, shadowed by sombre pines and granite crags, its course is run through plunging rapids to the final assault on the sea, where wide sand-barrens and desolation prevail.  Fremont understood this from his guides and says:  “Lower down, from Brown’s Hole to the southward, the river runs through lofty chasms, walled in by precipices of red rock.”  The descent

“of the Colorado is but little known, and that little derived from vague report.  Three hundred miles of its lower part, as it approaches the Gulf of California, is reported to be smooth and tranquil; but its upper part is manifestly broken into many falls and rapids.  From many descriptions of trappers it is probable that in its foaming course among its lofty precipices, it presents many scenes of wild grandeur; and though offering many temptations, and often discussed, no trappers have yet been found bold enough to undertake a voyage which has so certain a prospect of fatal termination.”

* These mountains, as the glacial accumulations began to permanently diminish, must have annually sent a long-continued huge flood of water down the rivers heading there.

He was mistaken about the trappers, not having ventured, for, as we have seen, there are traces of at least three parties:  that of Ashley, that of the missionaries mentioned by Farnham, the trappers also mentioned by him, and the one indicated by the wreckage discovered in Lodore by Powell’s expeditions, though the latter and that mentioned by Farnham are possibly the same.