I go walking in the woods in Acton all the time. As well as other towns in the area such as Carlisle, Concord, Bedford, Groton, Pepperell and my hometown of Chelmsford. Haven't seen any mountain lions but a lot of deer. This morning's walk is going to be COLD!
In the late 1950's and early 60's my folks thought every boy living in town, they sold their farm and moved in late 1958, needed a paper route so I delivered the Cheyenne Tribune every evening for about 4 years. The guy who brought the papers from Cheyenne was a "Lioner" named Rocky. He had a pack of hounds that he usually carried with him in his truck as he dropped off the papers at the little towns on his route. He fascinated us with the stories of lion hunting. Every so often he would make the local paper for catching one that had taken to chowing down on someone's sheep or calves.
There were several mountain lion sightings in Beverly last spring/early summer. I wonder if it is the same cat.
A great book on this subject is "The Beast In The Garden" by David Baron. Attacks on humans are likely to increase as these animals lose their fear of humans.