There are some good trails in Acadia - some good hard walks, if that's what you're after. If you have a bicycle and like to ride - there's a system of carriage trails through the woods that are perfect for that and give you a good workout- and then you can go eat lobster in Bar Harbor (which although it is a tourist trap - yes - is still a beautiful tourist trap) and you can get some excellent seafood there or near there at various lobster pounds on the road from Bangor through Trenton and then into Bar Harbor- and yeah, you could visit Miklos in Blue Hill and walk up the Blue Hill with him. He and his wife are lovely.
If you're going to Maine - get off the interstate in Bangor and take route 15 north toward Dover Foxcroft. Go through Guilford and onto Monson. Boarstone Mountain is a good climb - beautiful - not flat - you're working from the get-go but it's worth it - absolutely unspoiled views from the top. And then when you climb back down- you can go swimming in this little rock pool that's by the side of the road as you approach the base of the mountain.
Any thing you can do outdoors you can do in Southern Piscataquis. The region has an abundance of lakes, streams, rivers and trails providing four seasons of outdoor recreation. It is the home to many extraordinary craftspeople, who take great pride in their Maine traditions. Come visit us and discover a relaxed approach to the way life should be.
Hikers and backpackers will find the Southern Piscataquis region an ideal destination. This is the home to Gulf Hagas, named "the Grand Canyon of Maine" Gulf Hagas is one of most spectacular gorges in the Northeast. This 9-12 miles round trip hike will offer hikers some of the most dramatic scenery in the state. Borestone Mountain offers hikers a three-hour round trip to the 1,947 ft summit. The Mountain offers many hiking trails and a visitors and nature center. Boarstone Mountain is located near the town of Monson, which is a mecca for the region hikers. The world famous Appalachian Trail also passes through the Monson area. Other walking trails include the Pleasant Riverwalk located in Brownville, the Guilford Memorial Walkway located in Guilford and the Kiwanis Park located in Dover-Foxcroft.
Historical attractions in the region include: Low's Covered Bridge: built in 1830, the bridge was destroyed in the flood on 1987 and rebuilt in 1988. Katahdin Iron Works: Remains of this 1842 Iron factory located in Brownville include the blast furnace and the charcoal kiln. The Iron works is also the gateway to the Gulf Hagas region.
The Southern Piscatquis region is home to Sebec Lake in Dover-Foxcroft (6800 acres), Schoodic Lake in Milo/ Brownville/Brownville Jct. (7100 acres), Lake Hebron in Monson and Lake Wassokeag in Dexter.
For more information about the Southern Piscataquis region, please visit www.spccc.org
I wouldn't go in the spring though - blackflies. I'd save Maine for September myself, if I were you - incredibly blue skies, crisp air...also Sebec Lake, as mentioned in the blurb above is quite possibly one of the clearest amber waters I've ever seen.
Mt. Macginticook in/near Camden is also a nice climb - good workout- and beautiful views at the top and again, Camden has some nice restaurants and bars to relax in afterward.
For the spring - if you're willing to travel - I'd go to North Carolina. (I'm going in two weeks - hurray!).
Spring in North Carolina is beautiful. Dogwoods in bloom all over the mountains. Wonderful climbing in Pisgah Wilderness area, Tablerock, Boone, Great Smoky Mountain National Park, all along the Blue Ridge Parkway.
Asheville is a great town and a good place to stay accessible to everything. It's become a very cosmopolitan and fun little city. You could go to Bat Cave from there, Black Mountain, and if you travel west on forty into Tennessee- it just becomes ever more mountainous.
From where you are - Bangor (near Acadia) is a day's drive (8-10 hours depending on how fast you drive).
Asheville, NC is a fourteen hour drive. You could split that up by driving down to the outer banks - stay a day or two there and then over to Asheville, stopping in Chapel Hill for lunch. (That's how I always do it).