Went up to Cheesman Canyon yesterday with two good friends. Because of family duties, we couldn't get out until noon, so we decided to fish the afternoon and evening until dark. The flows were up to 400 cfs not a week ago and have now dropped to around 220 cfs. Anyone who fishes a lot of tailwaters knows that this is usually not a good thing. Highly pressured fish just don't tolerate those rapid flow changes especially when they are dropping. The parking lot was crowded as usual, but most of the cars seemed to be hikers and photographers with just a few fishermen spread out equally above and below The Narrows section.
We hiked to a couple of holes that had been producing some really nice fish recently, but when the flows dropped, most of those fish had moved up or down or under or wherever. Short story is, we had to kind of "relearn" the river again. So it goes.
We fished primarily dry dropper rigs with varying combinations of PMDs, pheasant tail varieties, and black beauties. Took most fish on the droppers. The afternoon and evening PMD hatches really never came off. But when they do, the fish will move a good distance for a well presented dry. We also nymphed up a couple on midge imitations as well. Use 6X fluoro, as little weight as you can get away with, and a sensitive indicator and sight fish in broken water. The fish holding in the slicks will reject your fly almost every time.
The tactics are what is really important. If you go with a buddy, try sighting for each other so you are casting to working fish rather than searching blindly. Sight fishing is a must! I know that it is hard to have your line out of the water, but watching a fish take a fly from a vantage point above the river in gin clear water can be just as exciting as hooking one yourself.
Bottom line - we hooked about a dozen fish and landed half. I know that doesn't sound like a good day, but given the conditions, it was pretty decent really for five hours in the Canyon. Gorgeous weather and the views are always top-knotch.