The highest mountain in Massachusetts, partly contained in Williamstown, although the summit (3491' above sea level) is in Adams. The summit features a lighthouse and a radio tower as well as Bascom Lodge. The AT traverses the mountain. Mt. Greylock is occluded from campus by Mt. Prospect.
The summit is the goal, or part of the route, of several runs, including the Schnellstiegen, THE Greylock Run, an annual tempo workout by the cross country team, and the Mt. Greylock Trail Races in the summer.