(Whiffletree, 13', 1971, 21-09-D) across Bittersweet Brook at Whiffle Tree Country Store NE of Billerica, Billerica Township, Middlesex County, MA. Andover Rd. NE (curves E.) 0.8 miles from jct with MA3A (Boston Rd.) in Billerica to the bridge on the S. side of the road at 101. (N42 33.841 W71 15.423) Photo by Dan Brock 8-7-02.