If mom is deliberately preventing dad from having access to the child then she is likely breaking the law... assuming WV has child concealment laws as we do in CA.
Dad can just as easily pick up the child and take it back home, or to a new home and should not hesitate to do so. Mom has left the home of her own will and she can do without the child until she gets an order.
So long as dad does not turn around and prevent mom from having reasonable access to the child he will be in the clear. If he picks up the child and returns it home, where mom took it from, it can hardly be argued that he is concealing the child if mom is choosing not to live there.
Yes, civil, but until there is a court order saying dad can't have the child there is nothing stopping him from picking up the child and taking it home... other than a locked door perhaps, but those locked doors might get mom in trouble.