I followed most of this abandoned in place line from Littleton NH to Saint Johnsbury, It is now a rail trail in Vermont but not sure about last year of operation in NH and E pf the CT River.
The line through Littleton was the B&M Berlin Branch, the last train was sometime between 1995 and 1997. The tracks were taken up from Woodsville to Littleton shortly after, and from Littleton to just east of the Bethlehem town line a few years ago.
The former MEC Mountain Division from Portland to St. Johnsbury last saw end to end service in September 1983. Twin States RR (NHV) was the last carrier, serving between Whitefield, NH and St. J until the closure of the Simpson Paper mill at Gilman, VT, towards the end of 1999.
Service to the former paper mill in Groveton ended sometime before the Simpson closure.