Subsequently the Government determined to effect an exploration of the headwaters of the Colorado, and to this end Major J. W. Powell, chief of the U. S. Survey Corps, was sent out in charge of a party of a dozen equally intrepid men, with instructions to descend the stream if possible. To accomplish his purpose Major Powell provided four staunchly-built row-boats in which he and his party debarked at Green River Station, on the 24th of May, 1869, to run the gauntlet of cañon, maelstrom, rapids and waterfalls in the Green and Colorado Rivers. It is to Major Powell’s report that we are indebted for descriptions of the terribly sublime scenery of these two streams, which surpass in wonder every other region on the globe, and to the photographer of that expedition we make our acknowledgments for several of the views which are here reproduced. Mr. W. H. Jackson, who was for a long while attached to the survey corps as photographer, has also kindly furnished us with a number of exquisite pictures of the more accessible cañons of the Colorado, and to him, therefore, credit in large share must be given. Our own party, while thoroughly equipped for photographing regions contiguous to railroads, was unprepared for making a trip down the most dangerous of rivers, and we have accordingly been compelled to rely for our photographs of the Green and Colorado Cañons upon the work of those above credited. Condensing as much as possible the elaborate and entrancing report of Major Powell, as it fills a very large volume, his explorations may be thus hastily described: