The last green valley is an area found in Massachusetts and Connecticut. It includes two river valleys the Quinebaug and Shetucket. Both of these river areas are designated as National Heritage Corriders, as set by Congress in 1994.
The name comes from the fact that this place is fairly sparsely settled when compared to many places that surround it. The entire region from Boston to Washington DC has become a megalopolis and the Green Valley is the one location that is not filled with people, buildings and dominated by what that does to the land.
The region shows up dark on night satellite photos due to its low population density. More than 75% of the land cover is forest or farmland.