There are bears all over central Maine, but you have to find a place where you and the bears won't have your plans changed by humans unexpectedly intervening, on ATVs and otherwise.
Nearly all bears taken with a bow in Maine are taken over bait that has been in place for weeks before the season.
I suspect that all the guides and outfitters are booked up by this time. The chance of crossing paths with a bear on your own is slim to none.
Sorry to not offer more hope, but that's the facts.
Jim