Split Child Custody rights & Opposing an out-of-state move, what to do?

Without parenting plan, all best are off. Either parent may move wherever he/she wants to move and if at the time of the move he/she has physical custody of the child, the other parent has no authority to stop them. This is assuming you are married, if you are not, you will have greater difficulty because unmarried Fathers do not have any residential rights unless there is a parenting plan in place -- you have parental rights, but no residential rights to the child. She can move without the other party's knowledge or consent without a parenting plan in place. So, you need to act now because once she moves out of state with the child, you will have great difficulty reversing things.

There is no time for you to delay on this. In fact, your battle is more up-hill on the basis that there is no court order in place. First, step is to file an action to establish a parenting plan in court. It sounds as though the two of you were never married. If this is true, then you would be filing a parentage action. If you are listed on the birth certificate or on the affidavit of paternity then you go straight to establishing a parenting plan and child support. If your name is listed on neither type of document, then you have to establish paternity by genetic testing first before the court can establish a parenting plan and child support. I assume that if DCS entered a support obligation with you as the non-custodial parent that you are named on the birth certificate and affidavit of paternity, so the court action regarding parenting plan issues will proceed without the genetic testing step. Second, file a motion for temporary orders, including a proposed parenting plan for the residential time and decision-making authority you are seeking. Note: the status quo arrangements (particularly, the most recent years) will have a direct bearing on what is likely in court. A 50-50 parenting plan may not be realistic if the arrangements that have been in place by agreement (with a court order) have not been 50-50, unless there are other facts to consider to even out the playing field. Once there is a court order - temporary or final parenting plan - then the custodial parents is mandated by statute to give notice of intended moves outside of the child's school district. When you file the case to obtain a parenting plan, make sure your county includes a temporary restraint that prohibits the removal of the children from the State or specifically request this relief. In the course of the case you file and once an order of the court is entered, if she makes mention of her desire to move out of state, she technically has to provide you with a Notice of Intent to Relocate and a Proposed Parenting Plan (that is if the court enters an order once the case is started that identifies her as the primary parent). However, whether she does or does not file the required notice, you may want to file a petition/objection to her relocation to preserve your objection. Even in cases where there is a court ordered parenting plan, the presumption is in favor of the primary parent being able to relocate with the child(ren). There are 11 factors listed in RCW 26.09.520 for relocation actions and the presumption is potentially rebuttable by the objecting parent to the move, provided the objecting parent has facts/evidence that would result in that parent carrying the majority of the factors in their favor. It hurts you somewhat that the status quo has meant the child is mostly with the mother. However, by not having a court ordered parenting plan, her ability to move with the child is made just that much easier. The relocation statute and the 11 factors are not at issue. I strongly recommend that you consult with an attorney regarding filing a case to establish a parenting plan and that to object to any intended relocation of the other parent. There is a lot involved from the sounds of your post, and therefore potentially a lot to lose with further delay.