Yeah, very odd for a buck. Don't usually see on trees that large, they like the little ones so they can wrap around it.
Bear claws usually go all zig-zag and look kinda-like lightning bolts. Unless, of course, they tear the whole thing up.
Squirrels won't usually go that hard on the thick bark, not that I've ever seen.
Do you have Porcupine i the area? They can tear a tree up real good and often go near the 7ft mark. The horizontal lines you're referring to could be a Porcupines teeth moving back and forth, like corn on the cob. He might have realized that bark wasn't worth the bite