Here's an unfortunate issue with most of our New England states.. the states A) don't have a lot of money to spend on the state forests. The state parks are more visited than the forests, so they put more money there. B) They state forests are NOT very well signed, due to A above.
Most state laws say that a road is closed if it is signed as such, gated or blocked in a way to prevent access. Being informed is our best defense and even a good offense. That means if you have a map with you and can show you are on a road on that map; if you have a GPS and can locate yourself exactly; if you carry a copy of the law; all of those will immediately put you into a place of "informed responsible" wheeler as opposed to "ignorant renegade" wheeler in the eyes of any EPOs you may come across.
If the private piece is generally open and the landowner doesn't really give a rats arse about it being used, then, do a little research; find out their name and make contact. Make a donation to their favorite charity.. which may very well be them,
get a Home Depot card or something similar.
The best and easiest way to win any confrontation is with superior information. If the road is INDEED closed but is not signed, the EPO is not going to bust your chops and he/she may even direct you to other places that ARE legal, as they now see you as a responsible user not irresponsible, taking off running, like you did something wrong.
The catch... This will take some work. You will have to spend some of the valuable time that you might have spent on this forum or any other and spend some time on the MA DCR site, you'll have to search through the MA state road law site and you'll have to spend some time asking around for the landowner's name, maybe research some tax documents.. might even mean taking an hour or so and heading off to the clerks office to find out.
The reason many of us "old timers" know so much is because we did everything mentioned and then-some to make sure we were in the right.
Go to the second post in this thread for a map of Freetown. If it says ROAD, we are allowed, during summer months (may not be during winter, as sleds have their time to play too) if it says TRAIL, we are NOT allowed. Its really that simple. Sometimes a road may also be listed as a hiking trail, but if it has ROAD in its name, than its a road.
Case in point: Makepeace Road, Payne Road are open roads, we are allowed there. Bent Rim Trail however, we are not. All the un-named trails shown are just that, as listed in the map key as multi-use motorcycle trails and as such are NOT open for our use.
To do this all correctly and legally will take work and it will mean working with local clubs etc to get information like where to find the info online (such as the laws, etc) if they're nice, they may even give that info out to non-members without making you go through all the work yourself.
Most people don't want to take the time or the effort to do things right so, that is one of several reason why we are always losing public places and will continue to do so until, in a very short period of time, we will have nothing left except paved or graded gravel roads. AND, it will be all our own fault.