The pic sucks so I'll  give you the best decrip I can give to aid in you helping.

It was about a size 10, it was the spinner stage (clear wings). It had a bit larger eyes then I am use to seeing on mayflies IMO. It had 2 tails, the main colors of it were somewhat of a grayish color with a bit of a ....I guess kind'a a brownish/rust color on the top of the body. It has sort of a brownish color between each body segment as well.

The spinner was found on the Au Sable here in Michigan around 9:45PM about july 15th. There were clouds of these up above out heads about 15 ft over the water at 9:30-10pm. The area we found these was right below a fast moving rocky riffle area.

Again sorry for the horrible pic, I forgot to switch my dig cam to the macro setting when I took it.