First Mass

August 1840

Documentation

• Gilbert J. Garraghan, S.J., "Catholic First Things in the United States," Mid-America: An Historical Review, vol. 21 (1939)
• Big Sky Words

Notes

Per Gilbert J. Garraghan, S.J., "Catholic First Things in the United States" (Mid-America, 1939), Fr. Pierre-Jean De Smet entered Montana on July 24, 1840, and — by his own statement that he said Mass every Sunday and feast day during his stay in the mountains — presumably said Mass on several occasions before bidding farewell to the Flathead and Pend d'Oreille at their camp at Three Forks on August 7, 1840. Big Sky Words independently traces this route and places De Smet's first Mass in Montana at Three Forks, in August 1840 — more specific on location than Garraghan, though the exact day within August isn't pinned down by either source. Three Forks is far from (and a genuinely different county than) the site's existing Montana entry at St. Mary's Mission, Bitterroot Valley (Ravalli County), September 1841. Wikipedia's articles on Pierre-Jean De Smet and on Three Forks, Montana both confirm the general geography and history.