Sent up the river by Captains Lewis and Clark, he travelled about eight miles, and observed the currents and sand-bars.

Leaving the mouth of the river, the party went on their course along the Missouri.

The journal, under date of April 27, says:-- "From the point of junction a wood occupies the space between the two rivers, which at the distance of a mile come within two hundred and fifty yards of each other.

There a beautiful low plain commences, widening as the rivers recede, and extends along each of them for several miles, rising about half a mile from the Missouri into a plain twelve feet higher than itself.

The low plain is a few inches above high water mark, and where it joins the higher plain there is a channel of sixty or seventy yards in width, through which a part of the Missouri, when at its greatest height, passes into the Yellowstone.