Raw bear meat is a 100% drop from bears, though it can also be dropped by grizzly bears. Members can buy it at the meat store in Canifis which stocks 10. Some bears can be found within the wilderness north-east of Edgeville.
After Doing the quest As a First Resort.... Raw Bear Meat can be bought from Chargurr the ogress cook in the spa town of Oo'glog.