Can you believe September is almost half over? I wish the calendar would slow down a bit. But the days are getting shorter, and it means Fall is almost here, with winter not far behind. Let’s get the most out of our fly fishing and ensure our September fly boxes are filled with imitations we expect to find on the river.

September Fly Boxes |

This is the time of year you’ll find a variety of insects on the water, from size 6 to 22! That’s a wide range for sure. On my local waters, I look forward to fishing the fall Green Drake and Flav hatch. For you, it might be Hecuba’s or Mahogany Duns. Each river system is different. The best resource is your local fly shop. Either stop in to see them or check if they have a “fishing report” section on their website. Many do.

Before I get too far, I want to share a short video from my RiverKeeper Flies YouTube channel of what I believe is an Ameletus mayfly hatching. Since I carry my camera, I spend time looking around for insects when fish aren’t rising, which happened last week.

I noticed this empty nymph shuck on a log and decided to photograph it.

Ameletus Mayfly Nymph Shuck |

I looked away for a couple of minutes and another nymph had crawled up on the log, only a few inches away from the first one.

I decided to take a couple of quick pictures and then set the camera on video to capture the nymph hatching. I was amazed it only took a few seconds for the mature dun to free itself from the nymph shuck.

And the final image of the adult…

Ameletus Mayfly Dun |

Here is a link to the video…

Now back to our fly boxes.

I seem to fish the same flies year after year. I’ve found they work for me. On occasion, I’ll add one, like Clark’s Big Mayfly – Green Drake I tried in June and worked very well. If you’d followed me for a while, you know how I like simple, but effective flies. Most are old-school, been around a long time. Trust me when I say they still work…really well!


When I look at these flies, most are what I call cripples or emergers. There are many more patterns to imitate this phase, so take your pick. Just have these in your box in case you come across a hatch. And don’t forget a Rusty Spinner to imitate the final Mayfly stage.

  • Green Drakes (size 10 – 12), Caudatella (size 14 – 16), Flavilinea (size 12 – 14)
  • PMD (size 16 – 18)
  • PED (size 14)
  • BWO (size 18 – 22)
  • Mahogany Dun (Size 16)


Lots of Caddis this time of year. An Elk Hair Caddis will work, but I like the X Caddis. If you haven’t tried an Iris Caddis, be sure to pick some up. They work really well late in the day.

  • Tan (size 16)
  • Yellow-tan (size 16)
  • Olive (size 16 – 18)
  • Gray (size 12 – 16)
  • October Caddis (size 10)


A Little Olive Stone is prolific on the Metolius. Many think it’s a Caddis when they see them flitting about over the water, but upon closer examination, indeed they are Stoneflies. Just sit along the shore and the bugs will crawl all over you! You’ll find they are sizes 16 – 18 and I use the Improved F Fly to imitate them.

The Cascades Stone (size 6) is a hatch I’ve seen only on the Metolius. Fish don’t key on them and they are quite elusive. Try an imitation along the brushy shore late in the early morning or late evening.

Golden Stones may still be available and the Clark’s Golden Stone in sizes 8 – 10 will work.


Never be without a couple terrestrial fly patterns. These are the two I carry.

Just as a reminder, this is what we’re looking for!

You’ll notice I don’t provide a list of nymphs (OK, look closely as I’ve offered one October Caddis nymph). It’s because I exclusively fish dry flies this time of year.

Enjoy…go fish!

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  1. Interesting, I wish I had gotten a picture. They were more of a dusty grey than the Ameletus. I was able to pick one up off of the water and checked its coloration on the bottom. It was also grey with some slight olive coloration between the joints. Could these have been a green drakes which had freshly hatched? Do they develop the green color with time?


  2. John,
    Thanks, as usual.
    Just looking through those patterns, great flies that are designed to catch trout, beautifully tied and photographed, and that wonderful video of a fly that anglers pay too little attention to but trout seldom ignore, gives me the insatiable itch to get out and fish.
    For now you’ve inspired me to get busy behind the vise, where I can scratch the itch with daydreaams as I produce patterns of my own – and try some of yours. When this ugly smoke from surrounding wildfires begins to clear, I’ll be ready.
    Best to you and Karen,
    – Chuck

  3. John – This is a really great post. Thanks for the list of suggested fall flies. I have a question. I was on the Met this last weekend and while I did not see any of the green drakes, I believe, I did run across some larger grey mayflies (grey drakes?) in a size 12-14 that the fish were taking. I have seen the green drakes in past years and I remembered them to be more green and larger in size than these. Or, am I mistaken and these were actually green drakes. Thanks.

    1. Hey George

      Thanks for the Comment. I don’t know of any gray drakes on the Met. I’d guess it was this Ameletus I featured in this week’s post.


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