From the South Orrington boat launch it is 2.5 miles to the Pierpont campsite (not made yet) on river right in North Winterport. From there it is 5 miles to the Frankfort boat launch on US Rt. 1A and Marsh Bay, river right. It is also 5 miles to PRPT Bowden Point campsite on the Penobscot Shores Preserve of Coastal Mountains Land Trust, not made yet, past Marsh Bay, staying mid river.
On the way down from Winterport, the river widens into Marsh Bay on your right, at the confluence of the North and South Branches of the Marsh River, Kikimessewihtek, Black duck stream. If the tide is not too low, the Maine Coast Heritage Trust preserve on Treat Point offers a good resting and hiking place. The point nestles between the North Branch of the Marsh River and the Penobscot River. The Frankfort boat launch is at the head of Marsh Bay back near US Rt. 1A.
Continuing down the main stem of the river, passing Marsh Bay on your right, the next land is Bowden Point in Prospect. Half a mile down the shore river right, you come to a campsite, not made yet, on Penobscot Shores Preserve, owned by Coastal Mountains Land Trust.
The town of Bucksport is 3 miles downstream from the Bowden Point campsite, where it is advisable to switch to a sea kayak to continue out the Penobscot into North Penobscot Bay, and pick up the Maine Island Trail. You can tie up to the dock at the Bucksport Marina and shop or eat in town. The Verona Island boat launch across the water from Bucksport is a good take-out place.