As a rural mountain rancher (though arguably not a proper cowboy), I would suggest that you would be ill-advised to marry one. I know loads of them, and while they are nice guys, they aren't the type that you are likely to find marital bliss with. Most have a hard time staying married, due in no small part to their almost uniform tendency to drink a lot and pick up girls whenever and wherever they can, married or not. Cowboy vices tend to screw up cowboy marriages.
Well, knowing how to set a proper fence post would go a long way toward making up for a few vices. Caught my last boyfriend filling the hole with rocks!