This loop is around 4.0 miles in length and connects to Boston Mountain Trail - Loop B
(it's easy to combine the two together).
Loop A starts right out of the visitor center parking lot. Look for the "Boston Mountain Trail" sign marking the trailhead.
Most of the trail consists of dirt, and of course, if you run in the fall, you'll have a lot of leaves on the path! There are a few small water drainage crossings that have well-placed boulders to use when crossing.
The first part of the trail descends slightly until you'll see the cut-off for Boston Mountain Trail - Loop B
. Stay left on Loop A and head all the way down the hill to the Y where you'll have the option to head either direction on Loop A. If you want to get most of the climbing out of the way at the beginning of the run, then stay right and head down to the creek.
From here, runners will get to climb up a moderate hill section and two other steeper hill sections. However, once you get to the top of the third hill, it's smooth sailing as you try to peer through the trees to get a quick look at the lake while heading back down towards the Boston Mountain Trail - Loop B
As you approach the Loop A and B junctions, after crossing the park road, be on the lookout for a Y in the trail (the one that you split from originally) about 25 yards into the woods. You'll want to turn right at the Y to head back out to the trailhead. You'll then head uphill on this short connecting trail and soon see the Loop B cutoff that you passed before. From there, it is just a short run back to the parking area.