If the other parent takes the kids out of state without my permission, can s/he be charged with kidnapping?
The answer to this likely depends on many factors, such as how long the parent is going to be away, what your custody order says about leaving the state (if there is a custody order), and whether or not the parent is giving you all of the information about where the child will be and allowing you contact with the child. Unless your custody order specifically says a parent cannot leave the state with the child, the other parent may be able to do so during his/her time with the child. If you are in the middle of a custody case, often times, the judge will order that neither parent remove the child from the state (jurisdiction) while the case is pending.
Under Oklahoma law, it is illegal for anyone (including parents) to maliciously, forcibly or fraudulently conceal a child from anyone who has custodial rights over a child.1
If you are afraid your spouse may take your child out of state with the purpose of interfering with your custodial rights, there are things you may be able to do. For details, see If I think that the other parent may abduct my child, is there anything I can do?
1 21 O.S. § 891; see Wilkins v. State, 985 P.2d 184 (Ct of Crim App 1999)