I have made 40 trips into Quetico.  All of them entering from the north.  I saw one bear at the BH parking lot.  But there was a sign warning about a problem bear.  I also saw a yearling swimming across Quetico Lake.  My wife and I saw a pack of about 6 wolfs on the south shore of Quetico Lake.  But I have also seen a wolf a quarter mile from my house and on US 53 on the way to Virginia, MN.

I think there is a causal relationship between seeing bears and how often a campsite is used.  Bear learn about campers and that campers mean food.  After dealing with a few campers they also figure out that campers are harmless.  IMHO the best way to avoid contact with bears is stay away from well used campsites and portages.  I don't use well used campsites and I don't hang my food pack.  After 40 trips I have never seen a bear near my campsite.