STB,
I'm not exactly sure what those "circles" are just east of the building. I'll guess that they are small clumps of conifers. They look a little like small ponds, but it would be a wierd spot for those. Keep looking east and there is an oval shaped small pond.(shiners?)
The hardwoods I refer to are usually the more sparce forested areas like those behind the house and near the pond across the street. (they may not all be oaks,maples and ash, but they're deciduous.) Remember... April in WI, the deciduous trees are just still greening up. Conifers (or pines) show up as the darker "fluffy" blotches. There is a huge stand of conifers across the street and further west after the building to the west.
That also looks like a nice natural knoll or funnel in a line directly running SW from the building.
The more I see it, the more I want to hunt it!!<img src=icon_smile_cool.gif border=0 align=middle>
Later
Jack