Hi Peter,
I realized I had made a mistake after posting this - John and Adelaide weren't married in Lac Ste Anne (Adelaide was born there), actually they were married in the mission, in St. Albert (built by Father Lacombe twenty years previously) by Reverend Father Leduc.
No, I didn't know about that record, thanks for letting me know, that's really helpful. I plan to go up to Edmonton in the next few weeks to visit the Provincial Archives and now I can look up this record as well.
Thanks again,
Maureen