indiana green houses?

to the side of the highway in indiana i noticed a bunch of school busses on a hill...   they commingled with some large semi-circle covers on the ground used to help grow plants.   basically my conclusion is that what i saw was the outer shells of old school busses which were being recycled and used as green houses.   my fascination made me get off the interstate and take the local (gravel) roads back a few miles in the direction of the farm to get a closer look and take photos.  unfortunately, i couldn't access the part of the farm where i thought i remembered seeing them.  instead i just took a photo of some cows feeding.