Just back from the San Juan. My buddy and I fished almost exclusively at Munoz. He prefers sz 18 BWO dry flies while I mostly fish small (24-26) Yong Specials midges. I was doing a bit better than him up until Monday. A cold front came in with overcast and low winds, and the duns were everywhere and fish heads covered the river through the midday. I hadn't planned on much BWO action, and that was the best hatch I'd ever seen there. Others we met agreed. I tried switching to emergers (18-22), but it was too late...they were taking everything on top. I picked up fish more consistently using a yarn indicator/drop shot rig over the whole trip, but when it clouded up and the wind was low, he did better. Not that we compete...we just have different tactics. I should have gone dry-dry during the blue wing events. I'll work on that for next year. Flows came down to 600 cfs when we started, and dropped to less than 500 when we left. For that area, I liked 600 better.