There are several long term trends that are making parts of Maine, and
parts of other states in the northern U.S. have more wilderness.

In the case of Maine, much of the state used to support a small farm
economy when the U.S. was much more agrarian than it is now. Now in
most of Maine, smaller farms are not economically productive (with the
exception of Aroostook County in the northeast of the state where
potato farms predominate). Over the past hundred years, much of
interior Maine that used to be farmland has reverted back to woods.

At the same time, over the last 40 years or so the population of the
state has consolidated toward coast, toward the southwest, and toward
urban areas, such that there are towns throughout Maine that are slowly
dimming and blinking out. Close to where I will be living there is one
town that no longer exists as a coporate entity, Centerville, and two
others that are trying to go in that direction, Whitneyville, and
Cooper (on Cathance Lake) Deorganization means lower taxes for these
towns on the brink. When deorganization succeeds, local control of the
community is given up. This ultimately furthers the trend toward
forested land.

Finally, much of the land in Maine is owned by international timber
companies. Currently they are managing much of the land for pulp
production, and letting forests regrow. If you didn't know better you
might assume much of the land is preserved.

The town where I am buying a house once had about 2500 people and was
an industrial center for cutting wood (thorough water power). Now the
mills are gone, along with the dams (thank goodness). If you didn't
know the history of the town it would be hard to imagine how industrial
the town was in the past.

That is what I meant.