Heh, I'm no pro, but I've shot 6 bears from 140 pounds to over 400 pounds and have seen about 50 in the woods while hunting, and many more while working for an Alberta guide back in the early 90's. No way you are going to tell from those photos. Its certainly not a cub, but thats as far as anyone can tell you. I've seen huge bears with big ears and small bears with tiny ears, the opposite from what it should be. Tall thin ones and short fat ones, everything in between.
But if anyone had to guess, I'd go with Woodchucker and say possible world record. It will beef up the excitement.
Fantastic to know they are around. Hope there are follow up threads on this one. I love bears!