The Holyoke Street Railway (HSR) was an interurban streetcar and bus system operating in Holyoke, Massachusetts as well as surrounding communities with connections in Amherst, Belchertown, Chicopee, Easthampton, Granby, Northampton, Pelham, South Hadley, Sunderland, Westfield, and West Springfield. Throughout its history the railway system shaped the cultural institutions of Mount Tom, being operator of the mountain's famous summit houses, one of which hosted President McKinley, the Mount Tom Railroad, and the trolley park at the opposite end of this funicular line, Mountain Park.