This picture was taken in about 1995 near Hillsboro, Oregon, at the edge of the "Silicon Forest." This tract of farmland is now a business park in the Silicon Forest.
Interwoven with the green wheat stalks was a considerable amount of a common vetch that grows wild in our area - see the little purple flowers all through the wheat.
Vetch in Bloom in a Field of Wheat in Hillsboro, Oregon.