Who else is in the picture

This photo was on the Findagrave entry for my great-grandmother, Alma Maude Oyler Jones. According to the caption, Alma is in the middle, with her hands clasped (above a man in a tie). The photo is not dated, but I recognize my Uncle Bob (my Gumpy's brother, Robert Paul Jones) in the first row with his chin resting on his palm, and my Gumpy as the youngest in the front row, next to the man in the tie. I am guessing this photo is from the mid-to-late 1930s.

Source: Findagrave entry for Alma Oyler Jones.

I do not know who these other people are, or where it was taken, perhaps from Thorntown, Boone County, Indiana. I think I recognize my great-grandfather Edgar in the top-left, above Uncle Bob. It would be great to know more about the others in the photo.