Geologically, the Mount Tom Range came about by our valley sinking and spreading to the east as the underlaying tectonic plate tilted upwards to the west, sinking to the east.  Glacial grinding exposed the basalt layer seen today and melting ice left deposits of granite and quartz from places far north, known as Glacial Erratics.  Further erosion and sedimentation from more recent Lake Hitchcock, helped shape lower elevations and much of our valley.  The New England National Scenic Trail follows the west edge of the upheaval that created the Mt. Tom ridge-line, affording excellent views of hills to the north and west, east and south across the Connecticut River Valley. Glacial erratics and a mixture of forest and wetland habitats can be seen throughout the Mt. Tom Range, filling a day with surprises for the curious as well as for serious professional and student studies.

For more on the geology of Mt. Tom and Mount Holyoke, log on to the Beneski Museum of Natural History at https://www.amherst.edu/museums/naturalhistory.