I'm looking for Indian-Quesnel unions also. I'm pretty sure those roots will have 3 main possible sources.
First, Raymond Quesnel b. 1697 in Montreal. He got a child (Raymond) out of marriage in Canada and we loose his trace after that in Canada. I suspect, but have no proof, that he is the one that Bourgmont Missouri River Expedition Diary call "Quesnel" without disclosing the surname. If so, he probably settled, (like many french-canadians at that time) among a tribe (Osage, Missouri ?) after the departure of Bourgmont for France. Raymond was the son of Olivier Quesnel and Catherine Prudhomme. I knew some other branch of Quesnel came from France around 1720-1730, but I think, before that period, all the Quesnel in the New World were descendants of Olivier and Catherine. But in a list of "Fort Detroit inhabitants who paid rent between 1707-1710" we find those 2 Quesnels:
Jacques Quesnel, no rent
Jean Quesnel, no rent
If Jacques is Jacques-François b. 1684 son of Olivier and Jean is Jean-Baptiste b. 1681 son of Olivier, then, we know that both married French-Canadians and we know that Jean-Baptiste died in Lachine, Montreal. It's likely they are the same brothers because we know that sons of Olivier were involved in fur trading. Even if it's still possible that those 2 brothers had children with Indians, I think the real interesting link here remains Raymond Quesnel b.1697. I would not be surprise if the Quesnels that we see involved in northwest exploration in mid 19th century are actually his descendance.
I think, if we go up in the tree from many Indian Quesnel in the midwest, it should lead us to that Raymond. I'm looking for any small clue about Raymond Quesnel in the midwest, the location and date of his death would be a huge help.