"Mattawa House" was established by the Northwest Company in 1784. In the 1820s and 1830s, the Hudson's Bay Company (after it had merged with the Northwest Company) sent canoe brigades from their Fort Coulonge Post to the Mattawa River junction in order to trade furs. In 1837, a permanent post was established, but was moved to a new site in the centre of present-day Mattawa in 1843. It was subordinate to Fort Témiscamingue and Fort Coulonge, but after the arrival of the telegraph in 1871 and the railroad in 1880, it became the headquarters of the Timiskaming District. As the fur trade diminished and the population grew, the post became a general store, trading merchandise to supply lumbermen. It closed in the early 20th century (1908 or 1912, depending on source).