Check out the Black Mouth Cur. They are a pioneers dog bred for hunting bear, hog, deer, squirrel, and to protect livestock, property and the family. In Texas they use them to herd cattle. In the south they hunt bear, boar, squirrel, coon, and deer. In the West we use them to hunt Coyotes.
They are considered one of the most well rounded "multi-purpose" dogs known. They are definately all "outdoor dogs" but will acclimate to inside "family" living with proper daily outdoor exercise. They are most definately a family dog!
They can track human or animals using both ground and air scent as well as any hound. Plus they do not bark until their on their prey if you're into stealth hunting. My dog has a Garmin GPS unit on him when in the woods. They are bred for the woods and outdoors. These are not dogs imported and bred for other purposes but rather are an American dog bred to deal with the hazards and lifestyle of wilderness Americans, Farmers, Pioneers, and Homesteaders. They are
extremely intelligent and train well. Old Yeller was a cur.
While no single dog is going to probably be 100% successful with a Mtn Lion or Bear...these dogs will not give up and they will die defending their "pack." They are tenacious, bold, courageous, confident, and strong depending upon which breeder you select. Knowing this - this is no lap dog. They need plenty of exercise, they need plenty of physical and mental challenges or they will go "bonkers". When not in the woods, I keep my dog challenge with various tracking and searching exercies. He is going to start Schutzhund (protection, tracking, & obedience) training starting next Spring.