Legal Question in Family Law in Washington

Re: child custody & leaving state

I am going to presume, by the expression "legal custody," that you mean joint decision making with the children residing most of the time with you, and you designated as the custodian for certain the purpose of certain state and federal laws. Yes, you may, you will have to follow the relocation provisions of Washington law. You have a summary of the law in the Parenting Plan. I have done divorces where the parties knew that they were planning to move, and incorporated that specific move into the final parenting plan (with the other parent waiving objection).