“A trail that runs around the perimeter of the Gunpowder State Park Sweet Air area.
— Cheryl Ladota
Open sunrise to sunset. The entrance has a sign identifying whether trails are open for bikes and horses to ride.
The blue-blazed Boundary Trail travels around the perimeter of this trail system, but has quite a few gaps where you need to jump on other trails. There are wooden trail maps at each of these branch points, but it can get confusing.
The trail begins across the street from the parking lot. There's a short singletrack run through the forest that opens up to an old farm road that goes along a cornfield. This area of the trail system can get confusing as the farm road is not blazed and there are many trailheads along the way.
Stay straight on the farm road until it heads back into the forest. You'll see a sign pointing towards the river, which lets you know that you are on the right trail. The trail has twisty uphill and downhill sections, some of which are a bit technical, but not too difficult.
When you see the river ahead, you'll come to a trail sign that identifies the Boundary Trail heading to the river and an alternate "middle trail" to the right. The Boundary Trail crosses the river at this point, but there is no bridge or even rocks to get you across. If the river is running low, you can cross without much effort, but this crossing can be difficult otherwise.
The Boundary Trail continues on the far side, but if you cannot get there, you'll need to move through other trails (orange and white) until you meet back up with the Boundary Trail when it crosses back over the river.
The Boundary Trail will not get you back to the parking lot. You'll need to jump on other trails (yellow and white) to finish out the loop.