Flagg Hill is a 4 mile lightly trafficked loop trail located near Boxborough, Massachusetts that features a lake and is good for all skill levels. The trail is primarily used for hiking, walking, running, and nature trips and is best used from March until November. Dogs are also able to use this trail but must be kept on leash.
This was a pretty nice trail through the woods and by a couple of ponds. I added about a 1 1/2 mile excursion into Heath Hen Meadow Brook Woodland which took me by the edge of the second pond. Stone walls and varied terrain made the lower half of the trail near Heath Hen more interesting than the upper half in my opinion. After the heavy rain yesterday, the trail was “soupy” with standing water and muddy in a lot of places no matter where you were and it took some ingenuity to navigate across. Parking is easy to find and is in a small dirt lot near Flagg Hill Pond. There’s space for about five cars.
This was a great path on a blustery fall day. There were a variety of different areas in the woods and a short walk across a field. The climb up Flagg Hill was fairly steep, but the rest of the hike was not bad at all.
Nice trail. Good elevation gain on first small loop that goes up and down Flagg Hill. Not muddy at all, but it has been a very dry spring and summer. Very minimal bugs -- hiked in end of August. Only lake is at the very beginning and there is no water access.
The mud is so bad on these trails that I'd recommend not hiking them at all in the spring. If you do, wear boots, and expect that you may have to step into pretty bad mud a few times. The trails are poorly marked in my opinion. There are a lot more trails than what you can find on maps (especially if you get the official maps from the Boxborough website or Stow website), and they have no markings on trees usually, so they can be confusing to people who aren't using GPS. The orange trail (seen on this site) doesn't appear in the official maps because it is on private land, but it seems to be cared for, and there aren't any signs against trespassing. Just be considerate if you use it. There is a lot of areas that are overgrown by Oriental Bittersweet (an invasive vine), especially in the parts that are in the Heath Hen area. I'm worried that it has spread enough that it is going to be very hard to control. I haven't hike this in the fall, but I assume that mosquitoes would be pretty bad, since there are so many areas of temporary standing water. The nicest thing about this hike is that there is a variety of things to see. There is an area (light green trail) where all the large trees are dead and there are thousands of young saplings growing to take there place, so that is pretty cool. There's areas that are old dirt roads, and areas that are just foot paths. The variety is kind of nice.