This list is devoted to the Bay Colony Railroad (BCLR) in southeastern Massachusetts, and now (as of October 2007) the new Mass Coastal which has taken over freight rail operations on Cape Cod. This list also covers several other eastern Mass. / Rhode Island shortlines, including the Grafton Upton (G&U), Fore River Transportation (ex-Fore River Railroad, ex-Quincy Bay Terminal), Seaview Transportation, Boston Railway Terminal, Narragansett Pier, and Union Freight, and the various industrial switching operations in eastern Massachusetts.

The Bay Colony operates or has operated 8 different ex-New Haven branch rail lines in Massachusetts including 1) Cape Cod > Middleboro, 2) Medfield > Millis, 3) Medfield > Newton, 4) Taunton, 5) Westport, 6) West Concord > North Acton, 7) Braintree > Nantasket, and 8) Braintree > Plymouth. Post any and all things related to the Bay Colony Railroad and the other included shortlines on this list.