The North Branch Penobscot River is a river in Somerset County, Maine. From its source at the outlet of Little Bog about east of the Canada – United States border in Maine Township 6, Range 17, WELS, the river runs southwest and southeast to its drowned confluence with the South Branch of the Penobscot River in Seboomook Lake in Pittston Academy Grant (T.2 R.4 NBKP).