Recent changes in Big Cat laws (blame that other Joe - Tiger King) make that really hard in the US without full sanctuary/zoo status (i.e. Single Vision in Florida). I don't know about N.A. Mt. lions - they act more like leopards in their solitary nature. Although some leopards can be social they can never be fully trusted; its really not in their DNA the way it is for African lions. Africa lions - if you raise from cub stage and invest a substantial amount of time in their development most are rewarded with lifelong pride (female) or coalition (male) membership. Pretty cool.
As far as bears - kidn of same if you raise with cubs, but they will go off on their own unless fenced in. There is a lady who has a relationship with a female bear - it always bring its cubs to her.
