This thread may have worn itself out, but a search for an urban legend about an enormous grizzly, on behalf of a gullible friend, did confirm the enormous lie but not the grizzly. It also turned up an instance of "genetically isolated critters" breeding back together, which was one of the key points of the originally cited article here.

The grolar bear, or maybe it's a pizzly bear, is proof positive that interspecies breeding is not limited strictly to sheep country (although it was found in Canada) ...

John