tippit, This bear's age I estimated but I should be pretty close based on the hundreds that I have seen aged.
I ran a bear camp in northern Quebec for many years and extracted bear teeth for the Quebec Ministry biologists as part of a bear aging project they were working on. In years that I did not remove and send in the teeth myself, I still kept the registration numbers at the check stations that did.
I kept notes of the bears we got and then matched the registration numbers with the figures that the biologists gave me in later months. An advantage I had was that I knew several of the people involved and they knew how interested I was in the results.
Age does not necessarily correspond with the size of skull. One of my bears that was officially aged at 21 1/2 years old scored "only" 18 7/16 in P&Y. I have seen 12 1/2 year old bears of the same size from the same area score an inch more. Skull size is only one way to categorize bears and big bears may be gifted in other ways... weight, square hide, length, age, etc.
Another was so old all they could say was "over 20"... his skull and teeth were in considerable worse shape and older looking than the 21 1/2 year old.
Rob Kaufhold, the owner of Tradtech/Lancaster Archery Supplies once killed a bear with us that was blind in one eye and had a thick cataract over the other. He only had a couple of claws remaining on each paw and was pathetically thin (about 180 lbs). If I remember correctly, it scored around 19". At one time that bear had to have weighed over four hundred pounds before hibernation. He had huge paws but his foot bones were loose in them... like a child wearing a father's slippers.
I love big or old bears and hunt them specifically. Each one is still very special to me even though I have killed many, many bears in my life. I don't mind ending the season without filling my tag though.
Those big ones are always boars and they may or may not be "old".
They are efficient predators that are hard on bear cubs and moose calves too.