Of 16 counties in the Pine Tree State, Penobscot County is fourth in terms of its size (3,557 square miles). Penobscot County is in Northwest Maine. Recent listings of riverfront land and property for sale in Penobscot County, Maine, totals roughly 1,000 acres and a combined market value of almost $300,000. The most common type of land for sale by combined acreage in Penobscot County is house. Browse all waterfront property for sale in Penobscot County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits! The most common type of land for sale by combined acreage in Penobscot County is house.