Green Hows Upper Tarn (and its near neighbour, Green Hows Tarn) was constructed as a boating and fishing lake for the owners of Graythwaite hall. It lies on Access Land and may be approached either from the Graythwaite-Crosslands road or from High Dam Tarn, ½ mile to the south.

It's reasonably attractive for an low fell tarn, with a concrete dam and spillway at the northern end. There is a boathouse near the dam, however it's far from a traditional one - appearing to be a steel framework clad in pine. Maybe it's a more practical replacement for an older structure.