I ride dirt and street and I carry IWB the same as I normally do any other time. I don't worry about falling on it and getting hurt because I figure if I go down that hard its going to hurt anyway, just make sure you have a properly fit holster with some kind of retention.
As far as full grown moose and bears, unless you commit to carrying a full size .44 magnum you'll likely just p1$$ them off if you shoot one
