Tower Mountain is located within Hancock, Massachusetts; it shares the summit ridge with Pine Mountain to the east; Smith Mountain is located south along the ridgeline, and Berry Mountain to the north. It is bordered by West Hill to the west across the Wyomanock Creek valley. Tilden Swamp, a highland bog, is located just below the summit to the northeast. The west side of the mountain drains into Wyomanock Creek, then into Kinderhook Creek, thence into the Hudson River and Long Island Sound. The east side drains into Smith Brook, Parker Brook, and Onota Lake, thence to the Housatonic River and Long Island Sound.