The deal in washington is say no and make them get a lawyer to challenge you chances are they wont spend 20-30 K and will just give up. The sherrifs dont want any ting to do with land disputes they come out and inform both parties of there civil options and call it a day. I have seen this happen in many areas where BLM,DNR state fish and wildlife land is landlocked. The other thing that happens here is one person sells there place and "forgets to tell" the buyer that there is an easement for acress to the land adjacent and the new ower thinks that since no one told him when he bought the place it not there problem.