A friend of mine is a ranger with the NFS. She started out at Arcadia National Park in 1989 and carried a .357 for protection against black bears and rabid animals. She left Acadia in 1994 and worked at sites in and around Washington DC for fifteen years before returning to Acadia in 2009. Now, when she goes out in the woods, she wears a Kevlar vest and carries an AR-15.
The Boston gangs operate meth labs throughout the park and then run their product down to the city in speedboats. She's had a couple of run-ins with them in the past couple of years.