Um, I take exception to Southwestern Ontario being characterized as "largely treeless". Compared to Algonquin Park, or Northern Ontario, there are far fewer trees, but there's hardly a farm without a woodlot, some of them quite large. It's not hard to imagine a bear going from woodlot to woodlot.

Some years ago, a carcass of a large bear was found near Delhi, Ontario, south of the 401. At first it was thought that a hunter shot it elsewhere and dumped the carcass in the south, but an autopsy revealed the bear died of natural causes.