Check Tall Trees, In the bear claw camp area.. as far as i know tall trees is the only place to hunt bear.
I personally run all over Tall Trees, although it's not super effective at times, I'll sometimes run into 1-2 and when I take them down, I just wait around for a dozen seconds and keep slowly spinning my camera looking for bears coming to avenge their comrades, even though that's strictly against what bears actually do since they're territorial predators. But yes, Tall Trees is the best and only place to hunt bears, although you can sometimes find them south of Manzanita Post but this is rare. Bearclaw camp and Tall Trees in West Elizabeth is your best bet if you're looking for some easy cash from the bears or if you're doing the Master Hunter challenges. If you are, I suggest shooting the bear twice with a strong gun in the head and then using your weakest gun, the revolver you start with, the Cattleman Revolver, shooting the bear in side/ ass once then knifing it, run away, knife it, run away, knife it, run away until it's dead. Sometimes it may strike you but, if you sidestep at the right time you can dodge them easily. If you do get hit run in a big circle to avoid the bear and regenerate your health. Good luck!
You can also kill many animals near tall trees, they will appear and scare you. When they do, get them.