Fields of Yellow Flowers

On the way out of Worthington, Indiana on Hwy 157,  just at a turn in the road, there is a huge field of yellow flowers. 

They look like yellow coneflowers to me, with some aster and purple coneflower in the mix.    I don't know if they've sown it for pleasure or to harvest seed.

In any case, it's beautiful.   From both the front and the back.  Here's the back