August 8, 1805
The tumor on Captain Clark's ankle… is still much swollen and inflamed and gives him considerable pain. The Indian woman recognized the point of a high plain to our right which she informed us was not very distant from the summer retreat of her nation... This hill she says her nation calls the beaver's head…
(As it is now all important with us to meet with those people as soon as possible,) I determined to proceed tomorrow with a small party to the source of the principal stream of this river and pass the mountains to the Columbia; and down that river until I found the Indians; in short it is my resolution to find them or some others, who have horses if it should cause me a trip of one month.