Winter Fly Fishing by Ben Johnston

Winter Fly Fishing by Ben Johnston w/flies by Allen Gardner

   As I approached my favorite stretch on the eagle river I was taken aback by how the the cold February sun shone through the frozen breath leaving my mouth. I fished the entire day without seeing another angled but left the river confused as to why I don’t see a single fish either. A few days later I walked into a fly shop and asked one of the guys on the floor what went wrong. I told him how I  had fished the same holes I did in the summer, and I knew there were fish there. That I had seen a small mid day hatch that normally guarantees success, and I used the same flies that were normally successful. He interjected “Well there’s your problem!” This confused me, but he went on to explain that certain bugs do not hatch with the lower temperatures. Around the town of Gypsum, for example, caddis generally will hatch from mid April and continue through October. But if the weather stays warm into mid November these bugs may continue to hatch until colder temperatures arrive. The hatch I saw around 11 was most likely midges, which the hatch chart showed to be present year round, and are small and black, unlike my bright green caddis larva fly.


 Allen Gardner, owner of, bug expert and author of his online entomology course explains some of the key food sources for trout during the winter months.


Knowing what insects are active in the river both in nymph and dry fly forms is very important to winter fly fishing.  Luckily for winter fly fishing, there are fewer bugs active in the water system.  While this sounds like a bad thing, it really means less options we have to guess through in our fly box.  Let’s go over a quick list of fly categories and stages we need to cover for winter.

Midges will be the bread and butter of the winter fly fishing , and make up the majority of a trout’s diet.  Midges will hatch during the warmest parts of the day often from 10 – 3 pm and can bring nearly every fish in the river to the surface.  This hatch alone can make winter fly fishing worth pursuing.

  • MidgesMidges
  • Stages: Nymph, Emergers, Dries
  • Sizes #18 – #26
  • Colors: Black, Blue, White, Red, Purple, Olive, Brown
  • Hatch Times: 10 -3 pm warmest part of the day
  • Patterns: Black Beauty, Miracle Midge, Pure Midge

Mayflies during winter primarily consist of Blue Wing Olives aka Baetis (BWO).  These mayflies hatch when the water temps get above 38 degrees and are best between 40 – 44 F.  They will also hatch during the warmest parts of the day 10 – 3 pm and can hatch on sunny days, cloudy days, windy days and snowy days.  Water temps and barometric pressure are the most important to predict a hatch.  Be on the lookout for changes in weather with warm water temps and you’ll have the best chance for BWO hatches.

  • MayfliesMayfly
  • Species:  Only BWO (aka Baetis, Blue Wing Olives)
  • Stages: Nymph, Emergers, Dries
  • Sizes: #18 – #24
  • Nymph/Emerger Colors: Black, Purple, Olive, Dark Olive
  • Dry Colors: Olive, Dark Olive, Purple
  • Patterns: Charlie Craven’s JuJu Baetis, Pheasant Tail, Mercury Baetis

Most stoneflies have up to a three year lifecycle and are always present in the water system.  I love fishing a stonefly nymph in a two or three fly nymph rig and using the inherent weight of a larger fly to get my smaller nymphs down in the strike zone.  It’s hit or miss with stoneflies in winter, but they can catch fish any day of the year and are worth a spot on your rig.

  • Stages: NymphStonefly nymph
  • Sizes: #8 – #16
  • Colors: Mixed or Solid Colors of Black, Brown, Yellow
  • Patterns: Pat’s Rubber Legs, Beadhead 20 Incher, Little Black Stonefly

Caddis are really only present as nymphs during the winter months and their larva patterns are either cased or free form.  The free forms look like monstrous midges and the cased caddis have cases built out of river material around them like a cross between a hermit crab and a butterfly.  Fishing deep to the bottom of the river with caddis nymphs will pull some fish during the winter and is a good bet if the above isn’t working. 

  • CaddisCaddis Nymph
  • Stages: Nymph
  • Sizes: #10 – 18
  • Colors: Brown, Olive, Dark Olive, Black, Cream
  • Patterns: ZWing Caddis Pupa, Buckskin Caddis, CDC Caddis Nymph

Scuds and sowbugs are present in spring creeks and tailwaters with ample vegetation.  Fishing these as a lead fly during winter is a good option if you’re fishing the aforementioned river types.  The further scuds get down from the tailwater outflow, the more brightly colored they become. When Scuds and Sowbugs die, they turn from their natural color, usually a shade of grey, to orange.  Fish hot spot patterns and regular patterns until you find the option that works best for the day.

  • Scuds & SowbugsScud
  • Stages: Nymph
  • Sizes: #12 – #18
  • Colors: Tan, Olive, Pink, Orange with Hotspots of Red (optional)
  • Patterns: Ray Charles, Generic Scudd Patterns

Annelids, aka aquatic worms are active year round in the water system.  Usually as flows rise, the annelids get flushed downstream and fish will target them more.  Regardless, the trusty san juan worm or a squirmy worm can be some of the most dependable bugs during winter.  

  • AnnelidsAnnelids
  • Stages: Nymph
  • Sizes: #8 – #16
  • Colors: Red, Pink, Tan, Neon Green
  • Patterns: San Juan Worm, Squirmy Wormy,  Rock Worm, Red Wire Annelid

Eggs exist from the brown trout spawn and provide an easy and nutritious meal for trout all winter. As flows increase, and the eggs get dislodged, they becomes more prevalent.  Big changes in flows makes a good day for the classic “bacon and eggs” rig.  Eggs are often brightly colored and serve as an attractor, motivating the fish to move for your bugs.  Often you’ll get a fish to move to an egg and end up eating the small midge you have trailed below it.

  • Eggstrout eggs
  • Stages: Nymph
  • Sizes: #10 – #14
  • Colors: Mixed or Solid Colors of Red, Orange, Pink, Yellow, White
  • Patterns: Pegg Egg, Yarn Egg


        I’ve found that presentation in the winter more than ever is key. You can have the perfect fly on, but not catch fish if you don’t have the right presentation. During winter the fish become sluggish eaters, and hold in slow, deep water. This means they can be more selective than in the summer when they tend to feed more actively and opportunistically. Fish hold in fast and shallow riffles and don’t have as much time to see what they are eating, which makes fly selection less important. Don’t be afraid to try Euro Nymphing, especially if you’re sight fishing to a single fish, as it provides more control and feel for your flies. Using small indicators can be helpful as the takes can be subtle, and big indicators can spook fish holding in softer water when they land. The risk of spooking fish by using indicators is another reason not to use an indicator at all if possible

        Sometimes, in the winter, you may have to fish a hole longer than in the summer.

       The fish love to sit close to the bottom in feeding lanes where they can expend a minimal amount of effort for the most food. Winter is all about being calorie efficient for fish, so they only expend energy if they know it will yield a calorie reward. I’ve found fish don’t like to move far to eat my fly in the winter. Methodically fishing every micro-seam in a hole, as well as paying close attention to depth tends to be the most effective way to put your bugs in front of as many fish as possible.

       There are some amazing stretches of Denver South Platte that present the opportunity to get out for a couple hours after work through the winter. My favorite section for trout is the Carson Nature Center, located behind Aspen Grove off of Santa Fe. Not only is this stretch loaded with rainbows willing to eat nymphs as well dry flies at times. This is a great way to get a little fishing time without spending the time needed to drive into the mountains.

        At the end of the day, fly fishing is still fly fishing, and the fish have to eat. Every angler has a different style of fishing that works best for him or her. If you are a streamer junkie and love throwing meat by all means continue doing so in the winter, but be ready to use slower strips and heavy sinking lines to get that bug right in the fish’s face. If you’re not afraid to tweak how you fish in the summer to fit the winter months you may just be surprised with the success you have.

-Tight lines

Ben Johnston

Fellow fly fishing addict

Last cast

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