Here is my thought on this.
I was under the impression that each year or every two years or how ever often we decide to do a coin that the coin would be different each time. For example we could choose different parts of the state to be represented on the coin. One year we could do the Coast and another year we could do farming and so on and so forth.
So my idea would be to call it “Northern Maine Woods” seeing that is the part of the state that the coin is representing.
Also if you think about it when referring to different parts of the state of Maine you use the following sayings, Northern Maine, Southern Maine, Western Maine, and Eastern Maine. It would not sound right to use these sayings, North Maine, South Maine, West Maine, and East Maine. So I say use “Northern Maine Woods”.
That is my opinion and I am sticking to it.
Here is the definition of “Northern” from the dictionary.
1. lying toward or situated in the north.
2. directed or proceeding northward.
3. a person living in a northern region or country.