Olivier Gravel was born in St. Eustache, Deux Montagnes County, Quebec - not in France - on 3 November 1853, son of Pierre Gravel and Flavie Lavallee. Olivier was baptized at St. Eustache the next day. Source: parish records of St. Eustache Catholic Church, St. Eustache, Comte Deux Montagnes, Quebec; volume 14 (1845-55), page 196, baptism #154 for 1853; available on LDS FHL microfilm #1033323.
He married Annie O'Connell - not Marguerite Fitzpatrick - on 2 July 1878 at Wolfe Island, Frontenac County, Ontario. Source: Frontenac County [Ontario] Marriages for 1878 at http://homepages.rootsweb.com/~maryc/front78.htm. See also the 1911 Canadian Census for Kingston, Frontenac County, Ontario.