I'm looking for a aerial shot of this farm but when the barn was there. Do you have anything older?

You might find some old aerial photos here. https://earthexplorer.usgs.gov

Hi Linda, 

Thanks for getting in touch with us! It's possible that we have some photos in this area from 1977. The tricky part is, we don't have approximate locations for the film, and essentially, we can't narrow down the search to confirm. There's about 63 rolls of film, and the only way to find something in that collection is to browse through the photos and visually recognize something. 

Here's the link to start browsing:
https://vintageaerial.com/photos/iowa/dallas/rolls?unmapped=true

If you do happen to recognize a place, be sure to leave a comment or pin the location on the map!