Their general course is from S.E.to N.of N.W., and they seem to consist of several ranges which successively rise above each other, till the most distant mingles with the clouds.

After travelling twelve miles they again met the river, where there was a handsome plain of cottonwood." Again leaving the river, Captain Lewis bore off more to the north, the stream here bearing considerably to the south, with difficult bluffs along its course.

But fearful of passing the Great Falls before reaching the Rocky Mountains, he again changed his course and, leaving the bluffs to his right he turned towards the river.
The journal gives this description of what followed:-- "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.