This journal entry, written in Lemhi County, is the first mention of bitterroot.
Capt. Lewis, August 22, 1805--another speceis was much mutilated but appeared to be fibrous; the parts were brittle, hard, of the size of a small quill, cilindric and as white as snow throughout, except some small parts of the hard black rind which they had not seperated in the preperation. this the Indians with me informed were always boiled for use. I made the exp[e]rement, found that they became perfectly soft by boiling, but had a very bitter taste, which was naucious to my pallate, and transfered them to the Indians who had eat them heartily.