Wilderness Survival Courses?

Wilderness Survival classes are likely to be very different from Wilderness First Responder classes.

Wilderness First Responder is an expensive, 8-10 day class in managing backcountry injuries and illness. Great WFR classes are taught all over the country by NOLS-WMI: http://www.nols.edu/wmi/courses/wfr.shtml. For other sources, try the outdoor programs at large universities.

Highly recommended.

Don’t know much about Wilderness Survival classes. I think they are focused on finding or improvising water, food, and shelter in the wilderness.

I have done both WFA and WFR in the past with SOLO in NH, a great outfit. I have also taken some survival classes at the Tracker School in NJ which are great though pricey and oriented toward primitive skills. It might be worth checking the outdoor programs at local colleges and universities, they sometimes host classes and open them to the public. The AMC website might also be worth checking since your in MA. I think focusing at least at first on a first aid class is the most applicable to backpacking. A lot of "survival", at least when applied to modern outdoor pursuits is really just advanced backpacking skills with first aid and crisis management. A good surival guide such as Tom Brown's series among many others, along with some practice can add the more immediate bushcraft type priorities such as improvised shelter, fire building, and water source selection if you feel so inclined.

There is a considerable difference between "survival" (a la Bear Gryllis, etc.) classes and various safety and first aid classes. IMHO, if you're backpacking, it's probably more important to concentrate on the latter.

For NOLS Wilderness First Aid classes, here's the schedule:
http://www.nols.edu/portal/wmi/courses/wfa/
I noticed a couple in Massachusetts, but I don't know if that is near you.

Other than that, area mountain clubs would be your best bet.