The posts above all seem to discuss a hike from the east, by the Firewarden's Trail, or north, by AT from Caribou Valley Road. It is also possible, and possibly preferable, to start from the south. Starting at Rte 4 in Phillips, you drive north about 13 miles on E. Madrid Rd. then a series of dirt roads until you reach a crossing of the AT in the "Orbeton Stream" section. Parking there, you take the AT east over Lone Mtn. and then the Mt. Abraham Spur Trail east to the summit. (On your return to the AT, you wouldn't be far south of Spaulding.)
Those dirt roads weren't bad in June 2005, when I took this route, but I don't know how they are today.