1892, 8 September: Dom Antoine, abbot of Oka, agreed to make a foundation at Mistassini on a property offered by the Canadian government located in a region designated for colonization in the forest at the confluence of the Mistassini and Mistassibi rivers, near Lake St. John. The first three monks sent from Oka arrived on 4 November 1892 and were forced to live in a dilapidated log cabin. They began work enlarging their living space and clearing the forest.
1893, 16 December: blessing of the first chapel.
1895, 13 September: visit of the minister of agriculture. The region began to be developed and settled.
1896: installation of a sawmill: floods and fires.
1897: establishment of the parish with resident pastor.
1909, 15 June: blessing of the cornerstone of the monastery by Mgr. Augustin Marre.
1911, 10 July: blessing of the monastery by his Emminence Mgr. Joseph Stagni, apostolic delegate to Canada.
1934, 26 July: blessing of the cornerstone of the church by Dom Pacome, abbot of Oka.
1938, 29 June: blessing of the church by Dom Francis Xavier Huet.
1942, 8 July: consecration of the church by Mgr. Georges Melancon, bishop of Chicoutimi.