56th Day Fly Fishing – Sepember 11th, 2025, 52-57 degrees
With the air finally cooling, the water temps are cooling too. This past summer was hot, but only the sixth hottest on record. The biggest effect on the summer heat from a fishing perspective is the way the water has been warmed by the sun, possibly more so than previous years due to low flows.
Last year I began taking temperature readings on nearly every trip to a river or stream. Some rivers seem to fare better than others. The South Fork of the Snake does much better than the Henry’s Fork for instance. This is due to the fact that at the dam, the Palisades reservoir is a couple hundred feet deep. Water exits the dam at that depth and stays cold all summer long. Even so, on my last trip to the South Fork, I measured temps at about 8 miles downstream and it was 66 degrees, which is still safe for trout, but warmer than I expected. In contrast there are several dams on the Henry’s Fork and most are shallow. Island Park Reervoir averages 12 feet and Ashton Reservoir is similar. Water in shallow reservoirs heats up much faster. Hopefully, I will be back on the Henry’s Fork soon. This time of year the weeds release and fishing picks up shortly after.
Today, my friend Ron and I fished the Duchesne River in Utah. From the Salt Lake area, you travel to Kamas and head over Wolf Creek pass. Ron was my guide today as I had only fished the Duchesne one other time and that was many years ago. When we arrived, at the river I was thrilled to discover that my first temperature reading was only 52 degrees. Toward the end of our fishing day at 2:30pm it was only 57. Readings at this time of year that are below 60 degrees are just fantastic!
The plan was to fish dry/droppers. Flows were still good, again for the time of year, but most of the fish could be found at mid-calf to knee depth, so a 2-2.5 feet long dropper would suffice. Ron started with a hopper on top and I went with a Bionic Ant, a Lance Egan pattern. I chose the gasolina perdigon below, mostly because it had done so well for me on similar freestone streams this summer. I’m talking about the Greys in Wyoming and Bitch Creek in Idaho, to name a couple. Ron went with a pheasant tail down below.
We both did fairly well on the first section. I got 4 on the perdigon and Ron managed six, all of our fish were small browns. Ron did manage one nice sized brown.
Above: Ron fishing the first spot
Our next spot was further downstream. We had to pass on a few spots that had trucks parked at the pull-out. The spot we chose was not ideal and Ron and I tried several spots. Ron did manage a 12″ brown on his hopper, and I believe it was the same fish that hit my hopper 10 minutes earlier, but I did not get a hook set. There was one run that I fished that was had some smaller fish in it, like 3-6″ in one small section of the run. I got four little fish to hand there.
Above: Ron fishing the second spot which had a beautiful red rock feature. Looked fishy, but wasn’t very
Next we decided to head back upstream, as we only had another hour to fish and I had to be back for my birthday party and of course, a shower was imperative prior! We went upstream past our fist put-in as it was also on the way home. The water and flow was just perfect. This section was fished heavily, in fact our fly fishing club brought 20 anglers on a Saturday about a month ago.
I had a few eat, right off the bat. These were all stocked rainbows. Ron refers to them as “stockers”. Anyway, I had one to hand, the othe got off at my feet and the third came off halfway in. I tie the perdigon.on a barbless jig hook. Barbless usually work well for me. However, the smaller rainbows jiggle as you bring them in. That wiggle will get them off of a barbless hook. Otherwise, with browns, I lose very few fish to a barbless hook. Generally, if I get a good hook set, that brown is coming in.
Above: this photo captures the third and final spot of the day. I would have loved to have spent a couple more hours in this spot.
Unfortunately, I had to get back to a birthday celebration (mine). The Duchesne fished pretty well, I ended the day with 8, Ron landed 10 or so. Small fish mostly, but Ron had at least one really nice one. It’s hopper/dropper fishing and that’s always fun, even though literally all of mine took the dropper. Ron was able to land a couple of his hopper eats.
Bottom Line: It was fun and I will be back!
