Franchère wrote a journal.

Hunt kept records.

Washington Irving wrote a popular book.

The overland expeditions of the era generated a documentary legacy that has allowed historians to reconstruct the journeys in considerable detail.

Marie Dorion left no written record.

Whatever she communicated about her experience, she communicated through speech, to people who then wrote it down from their own perspectives and for their own purposes.

The Franchère journal gives us two sentences about the encounter on the Columbia River.