On the parcel map it's just listed as blank space between lots.
Ok. that changes everything,
a lot. Apparently I was not communicating with you very well and misunderstanding the situation.
In dedicating the land to the town, the owner removed it from any individuals lot. This is contrary to what I was speaking of. In many situations, a government is given a ROW (easement) upon land for which it is dedicated as for the purposes of a roadway. The owner of the land continues to retain title to the land but relinquishes all control over the property. As such, he is a servient tenant. He would still pay taxes on the land as title holder.
It appears that not only was there a dedication but a grant of the land to the town for use as a roadway.
So, this is what I see:
as public land, a person cannot claim adverse possession (as he was told).
Now, it needs to be researched how such granted land is dealt with when it is abandoned by the "owner" (the town).
I do not know how Washington treats such a situation specifically. I have seen it treated, in other states, several different ways.
1. the owner of the land at the time of the dedication was either gifted the land or given the opportunity to purchase the land
2. it was split between adjacent landowners, either as available for purchase or as a gift, depending on the specific situation.
3. it was simply available for purchase by anybody with the money.
4. it was granted or sold to certain entities for use for a specified purpose. As an example, this is from where some of the pedestrian pathways are created in my area.
None of the above are applicable unless the government entity is willing to abandon the property.
If the town is not willing to abandon the land, it's a moot point.
You seem to be comfortable with the RCW so I would suggest searching for anything that controls the disposal of government lands.
I had a strange idea. No idea if it is even remotely a possibility but figured I would toss it out anyway for you to research if you believe it might be.
If B occupied A's land prior to the dedication, I wonder if B would be able to argue AP based on the period of time he occupied it while it was private property. To continue that thought, if it is argued the dedication severed any right to a claim based on the time, can it be argued that the dedication did not stop the accrual of time but that it becoming government owned land and it's subsequent return to private ownership should be considered nothing more than a disability that prevented a claim while in the possession of the government. If so, if A does succeed in getting the land, it could allow for a claim of AP by B.
Like I said, no idea if it is remotely possible but may be worth a little research if B is willing to initiate an AP claim should A obtain title.