The USFS guide commented that the problem is usually with women in the summertime.
He was actually NPS (National Park Service), not USFS, which is the Forest Service -- yes, there is a difference between Park Rangers and Forest Rangers!

Sorry to be picky about it, but when you hear it everytime you're in public in an NPS uniform...

http://www.nps.gov/archive/bost/Cassin_Young.htm

I had a friend who was a LE Ranger who pulled security duty at Charlestown Navy Yard right after 9/11; He had a good time and enjoyed seeing "Old Ironsides", especially since was an ex-Navy man himself.

T.