I was on the lower portion of the river, and yes they were taking a zebra midge size 20. Probably 80% of the fish caught were in slow slick water. I would stand back watching for any fish activity and then cast the midge to it. Usually it only took one or two drifts before they crunched it. I was using an indicator and was adjusting the depth to keep it a couple inches off the bottom. Had my best luck in holes around 4' deep with wood debris in the bottom, because of this I did lose quite a few flies.