Ruger Sp-101 .357mag.

Saying a person shouldn't carry a handgun in case of cougar attacks is like saying a person shouldn't wear a helmet on a motorcycle (I'd guess it's a fairly safe bet that cougar attacks have a higher survival rate than highway motorcycle crashes 55mph+, with or without helmets). On the off chance you have a need for it, better to have a slim chance of survival, opposed to none.

I don't even notice the SP-101 hanging on my belt unless my seatbelt catches it getting out of the truck (lefty with a crossdraw). .38spcls are plenty for Missouri.