Klein Innsbruck was, unfortunately, the last major eastern Massachusetts area to close. It began operation during the late 1960's or around 1970 in the town of Franklin, with a classic Hall double chair and a rope tow, on 4 slopes and a trail. Most of the slopes were not all the wide and were as wide as many of today's "trails" at larger ski areas. The area grew, adding another Hall double chair by 1977.
The area continued to operate thru the 1970's and 1980's, adding plenty of snowmaking to eventually cover 80% of the area. Night skiing was also added during the 1970's, as was typical of most eastern Massachusetts areas.
The rope tow was eventually removed and replaced with a pony lift at some point during the 1980's.
A view of the slopes in the 1980's, from their brochure. A. Hamilton also provided NELSAP a similar brochure. Notice how the slopes are not all that wide, and that there was a decent variety of skiing at this area.