Another vote for the 3 or 4inch Ruger GP-100. Yes it might not be the lightest gun in the world but it is very well built. I think it is built to last 100 years without much on the user's end other than normal cleaning and such. For stuff like Mt. lion you would want something with a good amount of punch, the .357 mag fit the bill nicely.

If you want something your wife or a weaker person can fire then you want something with a bit of weigh to the gun. Lighter gun almost always means heavier recoil.

Give the GP-100 a try MM. Ruger is known to build their stuff like tanks.

Semi-autos are perfectly fine if you are against 2 legged animals, but if I know I might be going against 4 legged stuff that is 2x+ my size then I go for the wheelgun.