Part of the Pawtuckaway State Park system of trails, Mountain Trail is a long, meandering piece of doubletrack that connects up to a few other trails in the system.
From the main parking area, you would ride down Pawtuckaway Road for about 1/4 of a mile to get to the trail, which will be on your left side. There is also very limited parking at the trailhead; maybe a couple of cars can fit just off the road there. Better to park in the main area and ride the short way to the trailhead for a nice warm up.
As you turn onto Mountain Trail, glance to your right just past the gate and notice Woronoco Trail
coming in. Keep straight and follow the sign to stay on Mountain Trail. Quite a ways in, there will be another trail that comes in on the right; this is South Ridge Trail
. Stay straight/left for Mountain Trail. Once you hit Tower Road, you know you've reached the end.
Mountain Trail can be deceiving. While it seems at first like a mellow piece of doubletrack, you'll quickly find that there are some really steep climbs that must be conquered along the way, some of which have some rocky features. These can be quite challenging, so make sure you're in shape!
Otherwise, the trail is a nice piece of doubletrack that, while maybe not the most interesting trail, is a good warm up for other trails you might encounter along the way, or even a solid climber if you're feeling like pushing it.