The M&M Trail was designed in the 1950s by the late Professor Walter M. Banfield of the University of Massachusetts Amherst as an extension of the Metacomet Trail in Connecticut. The route was constructed utilizing newly blazed paths, abandoned farm roads, and existing hiking trails (many of them several hundred years old) where available. Portions of the route on Mount Monadnock and the Holyoke and Mount Tom ranges date back as far as the 18th century. Early trail-building was supported by various summit resort hotels popular in the 19th century. Such resorts once stood on Mount Holyoke, Mount Nonotuck, Mount Tom, and Mount Monadnock (at the Halfway House site). Most of them had burned down or had become defunct by the early 20th century and never recovered. Encroaching development and modern transportation hastened the demise of these businesses by shifting tourism to more remote and exotic locations. Many of these properties were eventually bought, taken, or donated for inclusion in various state parks.