“In this direction Captain Lewis had gone about two miles, when his ears were saluted with the agreeable sound of a fall of water, and as he advanced a spray, which seemed driven by the high southwest wind, arose above the plain like a column of smoke, and vanished in an instant.  Toward this point he directed his steps; the noise increased as he approached, and soon became too tremendous to be mistaken for anything but the Great Falls of the Missouri.  Having travelled seven miles after first hearing the sound, he reached the falls about twelve o’clock.  The hills as he approached were difficult of access and two hundred feet high.  Down these he hurried with impatience; and, seating himself on some rocks under the centre of the falls, enjoyed the sublime spectacle of this stupendous object, which since the creation had been lavishing its magnificence upon the desert, unknown to civilization.

“The river immediately at this cascade is three hundred yards wide, and is pressed in by a perpendicular cliff on the left, which rises to about one hundred feet and extends up the stream for a mile; on the right the bluff is also perpendicular for three hundred yards above the falls.  For ninety or one hundred yards from the left cliff, the water falls in one smooth, even sheet, over a precipice of at least eighty feet.  The remaining part of the river precipitates itself with a more rapid current, but being received as it falls by the irregular and somewhat projecting rocks below, forms a splendid prospect of perfectly white foam, two hundred yards in length and eighty in perpendicular elevation.  This spray is dissipated into a thousand shapes, sometimes flying up in columns of fifteen or twenty feet, which are then oppressed by larger masses of the white foam, on all of which the sun impresses the brightest colors of the rainbow.  Below the fall the water beats with fury against a ledge of rocks, which extends across the river at one hundred and fifty yards from the precipice.  From the perpendicular cliff on the north to the distance of one hundred and twenty yards, the rocks are only a few feet above the water; and, when the river is high, the stream finds a channel across them forty yards wide, and near the higher parts of the ledge, which rise about twenty feet, and terminate abruptly within eighty or ninety yards of the southern side.  Between them and the perpendicular cliff on the south, the whole body of water runs with great swiftness.  A few small cedars grow near this ridge of rocks, which serves as a barrier to defend a small plain of about three acres, shaded with cottonwood; at the lower extremity of which is a grove of the same trees, where are several deserted Indian cabins of sticks; below which the river is divided by a large rock, several feet above the surface of the water, and extending down the stream for twenty yards.  At the distance of three hundred yards from the same ridge is a second abutment of solid perpendicular rock, about sixty feet high, projecting at right angles from the small plain on the north for one hundred and thirty-four yards into the river.  After leaving this, the Missouri again spreads itself to its previous breadth of three hundred yards, though with more than its ordinary rapidity.”