Well, that makes two of us! I've been looking for the same information for the last few years since Casimir Denault is my great-great-grandfather.
I have not found their marriage in the church records of the Fort Coulonge area.I was told by an uncle that Casimir was married in the church on "l'Ile aux Allumettes".But that church burnt down and no records are available.
I was also told to look for "mission" marriage records for that area around 1840-1850 since RC parishes were not established till later (after 1870 ?). So, the question is, who were the missionnaries in the area ? And where can we find those records ?
If you are in the Montreal area, you'll find my name in the phone book.