Mt. Agamenticus, Maine is a vast, near wilderness area a few miles from the busy beaches of York Maine and Rte 1. Sensational trails for running, walking, snowshoeing and mountain biking. ATV's etc.. are by permit only as I understand it. Land is made up of water reservoir ponds, conservation, and private lands.
A major effort is underway to conserve thousands of acres of this the largest contiguous forest near the ocean in the Northeast and Mid Atlantic. http://www.yorklandtrust.org/mta2c.html.
My mother is heavily involved in this incredible effort
Trails at the summit of Mt. A are well marked with maps available. Busted spoke has a good description of the trails in the immediate area of the summit. http://www.bustedspoke.com/trail.php?tk=1006
More expansive and wild and in my view better running are the outlying areas of Mt A between the peak and the York River, in the water district lands. Trails in these outlying are not marked but easy to follow. Best bet is to use the following 1956 topo map: http://docs.unh.edu/ME/york56nw.jpg
Turn onto 91 at the Ford dealership on Rte 1 in York. I access the trails from the road just before Payneton on the map. Turn on the dirt road at the white sign Wild Iris Farm and park about 400 yards up on the left. Walk up the dirt road and look for the woods road at the top of the hill, turn right and you are on your way. Note that these trails are not marked and it is very easy to get lost. Have fun exploring!