 Located at the mouth of the Machias River between the towns of Machiasport, Machias, East Machias, Whiting, and Cutler, it is separated from Little Machias Bay to the east by the Cutler Peninsula, from Little Kennebec Bay to the west by the Point of Maine, and from the Gulf of Maine to the south by Cross Island and the Libby Islands.The bay extends roughly 7 mi.