He was interested in the dramatic episodes of the overland journey: the encounters with Indigenous nations, the physical hardships, the near-disasters on the Snake River.

The account he did not write, because the framework of his narrative did not position it as the primary story, was the account of Marie Dorion’s 1814 winter survival journey.

Irving’s “Astoria” ends, effectively, with the sale of Fort Astoria to the North West Company in 1813.

The subsequent events — the Reed party expedition, the attacks, the winter survival — fall outside the temporal scope of the book.

Had Irving extended his narrative to include the winter of 1813-1814, he would have had access to accounts of Marie’s journey that were more detailed than what has survived in other sources.