As evening approaches and the sun goes down in the West, the combine keeps on going until it's too damp to continue or the field is done. In this photo the grain is very dry and the wind is not blowing, leaving a long trail of dust. When I was on the combine back in the '60's we didn't have a cab. Going with wind was very uncomfortable as the dust made it difficult to breathe. The dust was also very itchy. So, enjoy the photograph without having to experience the dust and the itch.