The Manhan River is a river (10.9 miles long) in central Massachusetts. It is a tributary of the Connecticut River. The river begins as an outlet of the Tighe Carmody Reservoir, Southampton, and flows first southwest, then northeasterly through the middle of Easthampton, Massachusetts to its confluence with the Connecticut River at a westward curve called "The Oxbow." The river provides excellent views of nearby Mount Tom. A former railroad has been converted to the Manhan Rail Trail, which now provides a scenic pathway along the river. Manhan River from July 1 through September 30 best time for flyfishing.