I've noticed three kinds of black bear claw marks on trees. The first is the kind shown in pics in this thread above, where bears are eating the softer layer under the outer bark. That girdles and kills trees, which is why the forest companies tried to exterminate black bears on the west side in the 50's. I've not seen many of those kind of bark peelings east of the mountains. My personal guess is that nutrition is so hard to come by on the wet coast that the bears eat bark more on the coast.
The second kind of bear scratch I've seen, mainly in the interior of British Columbia, is vertical claw scratches on big cedar trees. Often those are near a lake. I have been told that bears are making their territory and by the height of the scratch are telling other bears how big they are. That sounds like a human interpretation to me but could be true.
The third kind of scratch, common to find in the interior of B.C., is claw marks in the bark where a bear climbed the tree, and leaves claw scars in the bark. Those are common on poplar trees in the interior of B.C. Sample shown below.
