Quercus borealis maxima (Beaman Oak) Massachusetts (North Lancaster) Photo. by E.H. Wilson, Jan. 10, 1925. The largest oak tree in Massachusetts, the Beaman Oak, was in Lancaster on Route 117 east of Main Street. This oak, whose circumference was 17 feet, was located on what was the land of one of Lancaster’s earliest settlers, from around 1659 - Gamaliel Beaman. The tree had come to be known as the Beaman Oak. The tree severely damaged during a storm in 1989 and had to be removed.