North of St J, the line continues to Newport, VT before leaving the US and then returning briefly (Richford?) before leaving for good and heading towards Montreal. VTRS/Washington County operates the line up to Newport, where they interchange with the MM&A (Montreal Maine & Atlantic). The line through ST J up to Newport and down to Wells River was part of the CP back in the day.
Also in St J, there's the line east to New Hampshire which I don't believe is in service anymore but isn't abandoned. The line to the west is the old Lamoille Valley/County/StJ&LC line which ran to near Saint Albans. I believe that's abandoned.
-Jay Hogan