The rolling hills are green from plenty of rain falling all summer. My dad's farm was made up of a lot of landscapes like this and he planted them with corn or beans. Cattle grazing on the hills seems to be the only use of thie land.
Unfortunately I did not get photos of cows. Maybe I can dig into my archives and find cows on the hills for you to see. Black angus seems to be the breed that is dominate in southern Iowa even though I have seen some of the others in the area.