Fall Fly Fishing Hatches

Fall Fly Fishing: Bug Hatches

Autumn has arrived, some think of this time of year as the second spring when every leaf changes color. For anglers, fall is a time to rejoice, with cooler water temperatures, happy trout, and some peace and quiet on the streams. It can be a wonderful time to hit the water in search of that last good tug until old man winter comes knocking. For the trout, it can be their last window of consistent bug hatches where they can really get on the feed. The fall can have its ups and downs, all dependent on what the weather patterns might be doing. But it can be very very rewarding for those anglers who stick it out. In order to understand how to effectively fly fish during the fall season, below you will find a basic guide to Fall’s bug hatches as well as some recommend fly patterns.

Ethics Disclaimer: A quick note to mention before we get too far into fall fishing, is that the fall is when the brown trout spawn on our local rivers. These brown trout move into shallow areas usually in or in front of tributaries where they will create spawning beds or Redds. As anglers, it is important to be aware of this and to not disturb spawning fish. And do not walk through these spawning areas. It can disrupt this natural process. Check out a more in-depth blog about trout spawning here

Blue Winged Olives Hatches: 

The first and most prevalent insect that anglers should be focused on during the fall is Blue Winged Olives or BWO’s. These bugs are present most of the year but in the spring and fall water temperatures are ideal for the BWO’s to hatch. This insect is a type of mayfly, generally found in a size #18 or #20. They can be as big as a #16 or as small as a #22. These bugs are often dark olive, blue, grayish and prefer to hatch on cloudy rainy days. They will typically hatch mid-day in the fall and the hatch can last a couple hours. You can fish this hatch on the surface with dry flies or below the surface with emergers.

When fish are keyed in on the BWO’s you can see them sipping them off the surface or eating them just below the surface. Oppose to when the fish are eating caddis and eating more aggressively on the surface. Look for these small bugs in the surface film or foam in the back eddies.

Barr Emerger

Recommended Flies:

BWO Nymph Patterns include: Barrs Emerger #18-20, Juju Baetis #18-20, Magic Fly #16-20, Darth Baetis #18-20, Split-back BWO, #18-20, WD40 #18-22, Black Rainbow Warrior #16-18.

BWO Dry Fly Patterns: Parawulff #18-20, Parachute Adams #18-20, Film Critic #18-20, Hackle Stacker BWO #18-20.

Caddis Hatches:

fall caddis hatch 

The Fall caddis hatches on our local rivers can be a little underwhelming compared to the summer caddis hatches we have. However, when the fall caddis or as many refer to them “October Caddis” do come off it can be a feeding frenzy. These caddis a larger in size, around a size #12-#16 versus the smaller summer caddis. The color of these caddis are darker brown and orange. This hatch comes off later in the day often in the afternoons and into the evenings. Tossing on a caddis dry fly in the evenings can be a great way to entice a trout to come up to the surface.

Recommended October Caddis Fly Patterns:


Caddis Nymph Patterns: Soft Hackle Hares Ear #12-16, CDC Caddis Emergers #12-16, Z-Wing Caddis #12-16.

Caddis Dry Fly Patterns: Elk Hair Caddis #12-#6, Orange Stimulator #12-16, Goddard Caddis #12-16. 

Fall Stoneflies:

While most of our stonefly hatches, occur in the spring and summer there are still a few different stonefly species hatching in the fall. The stoneflies are smaller black and brown stones, sized #12-16. These stoneflies are prevalent in September and October. This hatch is sparse so while the fish don’t really key in on it, tossing on a stonefly nymph as your lead fly can produce some bites. Due to the lower flows this time of year, using a smaller strike indicator can work better to not spook the fish.

pats rubber legs

Recommended Stoneflies Fly Patterns:

Pat’s Rubber Legs Black/Brown #8-14, Micro Stone Black or Brown #8-14, Twenty Incher #8-14.

Midge Hatches:

Midges are the universal bug for trout. They are found year round in almost every river system. Like it or not in the fall trout will eat a lot of midges. Especially when some colder weather moves through for a couple of days. This will stabilize the trout’s metabolism and result in them being lazy like they are in the winter. So, if you end up fishing this fall during a cold front, toss on a couple midges and you will be surprised at how productive it can be.

Zebra Midge

Recommended Flies:

Zebra Midge All Colors #18-22, Midge Bomb #18-22, Rainbow Warrior #18-22, Top Secret Midge #18-22, Grifiths Gnat #18-22. 

Terrestrials, Eggs, and Streamers:

Hopper fly

Fall is sort of a funky time of year for the trout as there are some not so common food sources prevalent. At the beginning of fall, terrestrials like grasshoppers, ants, and beetles are found on almost every river. The fall grasshopper fishing can be really exceptional. If the fish are a little more pressured and not that willing to come up to a grasshopper, a lower profile bug like an ant or beetle can entice the bite. This is especially true in shallow lower flow systems. Throwing on a small ant on 6X and a lightweight rod can produce some quality fall trout.

Recommended Terrestrial Fly Patterns:

Chubby Chernobly #6-16, Obi Wan Chernobyl #8-16, Amys Ant #8-16, Fat Albert #10-16, Swishers Foam PMX #6-16, PMX #6-16.

Near October and November the fish will stray away from eating terrestrials. This is the time of year when the brown trout spawn as well as many of the local whitefish populations. Due to these fish spawning, there can be a lot of fish eggs in the rivers. The eggs provide the trout with a protein packed meal. Toss on a egg below an indacator and a beadheaded fly. Do you best to match the color and size of the current eggs in the river. A chartreuse egg is a popular pattern for many guides.

Flash-tail Egg

Recommended Egg Fly Patterns: 

Nuclear Egg #6-8, Clown Egg #6-8, Micro Egg #6-8, and Peg Egg Beads Various Colors.

Another aspect to mention about fall fishing that may not pertain to the actual hatches and entomology is that fall streamer fishing can be very productive. The water temperatures hit a sweet spot where it puts the trout in a place where they are willing to chase and react to a baitfish pattern. The fall is also when the brown trout spawn, so these fish can show some aggressive behavior before and after spawning. So, if all else fails and you can’t figure out what bugs the fish are keying in on, toss on a streamer a see what happens. Be sure to check our previous two-part blog about streamer fishing here.

Double Gonga

Recommended Streamer Patterns: Double Gonga, Thin Mint, Natural Sculpzilla, Mini Dungeons, Peanut Envy, Wedgehead, and Cheech Leech.

Fall Fishing Techniques:

Now that you are aware of all the different bug activity here are a few basic pointers to keep in mind when fishing the fall.

  • Check the weather forecast. Colder mornings can prove to be not productive. Begin focusing efforts on the middle part of the day for the more consistent hatches like the BWO’s and Caddis.
  • Rain can be good! If rain is in the forecast this is great news for anglers. The rain this time of year can provide the fish with cooler water. It can bring up the water levels in the rivers which can make the fish more comfortable and more active.
  • Cover a lot of water. Water levels in the fall can be very low. Do your best to cover a lot of water in search of finding fish. Esspecially when throwing dry flies and terrestrials. Sometimes this time of year, rivers are crossable. Cross the river and work water that isn’t normally fished.
  • Keep throwing the hopper! For some reason, many anglers put away the hopper box come September. This month can be one of the most productive months for hopper fly fishing. Keep fishing that hopper and tie on some a beadhead below hopper.


Fall in #troutcountry can be a great time to get out and enjoy some quality fishing and above-average sized fish. Just like the anglers, the trout are trying to take in that last little bit of good weather before the cold winter arrives. By having a good knowledge of the fall hatches, anglers can fill their fly boxes to be ready for the various hatches. For up-to-date fishing conditions be sure to check out our fishing reports. And if you are interested in booking a guide fly fishing trip with one of our guides, call the shop at 970.926.0900 or find information here.

Patrick Perry, Former Guide, and Content Contributor, @patperry