I live in Northern Maine and FWIW. Some of you hit the nail on the head. Deer are not that plentiful in the northern areas of the state. There are some but not like the rest of the state. Very hard hunting with thick woods and dense swamps. Thousands of acres of un broken woods and swamps. There are deer but unless your lucky it's hard to find them deep in the woods. The guys that get deer year after year in Northern Maine usually track them on snow. They cut a track and follow it till they jump the deer. You may take one once in a while standing in a field or crossing a logging road, I have myself. However IMHO tracking is the best way to get them year after year. The mid and southern parts of the state are more open with farming fields and more deer. If you want deer the normal way then the southern part of the state is where to go. If you want to hunt deer the traditional way that Mainer's have been hunting for a 100 years. Then head north and bring your snow shoes.
Bear are a different story. The north has bear and lots of them. They are every where and the bear hunting season is long. There is a bait season, a dog season and a general hunting season. I can see bear almost every day of the week. I have them on my camp porch, in my garden, and even looking in my window at my house. The old saying around here is "there are more bear than people". The moose population is stable in the north and we have a lotery draw for permits. With all the logging the new growth trees are prime moose areas. Moose can be seen about any night on a drve to town. Just last night I lost all the cabage in my garden to a cow and a calf. Moose have killed 7 new apple trees in my orchard and got all my neighbors blue berries. However they are tasty so we put up with them!
Northern Maine is also home to a large population of coyotes, bobcats, fisher, marten, fox, otters, beaver and most other fur. It's an ideal area for a trapper.