you can call pd , campground management, or lodge a complaint with child services. to do nothing except being upset does not help the situation...if you get a chance & the wife is alone, grab a chance to speak to her and ask if there is anything she needs...any help, is she ok? does she need a ride? each state, county etc, offers safe homes for women & children in abusive situations. there are actions that be done to stop the abuse.

and like I mentions, call police. if it is bad they will arrest him & hold him until he is sober (if that's an issue) or until family is safe. some states require a hold once a call is made regardless of what family says. if offers a period of space to make some plans and breathing room. there are options for victims of domestic abuse, all it takes is someone to start the ball rolling...by not watching and doing nothing