Angler 101: Salmon Fly Is The Best Bug to Catch Big Trout

By Last Updated: October 12th, 2023Categories: Fishing

To catch loads of fish, old fishermen will use live bugs for bait. And among all those tiny creatures, the salmon fly is definitely the ace for harvest, especially for bug fish.

In Montana, this fly is considered the ace for hunting big trout in the river that will never waste time eating small “desserts” but big “feasts”. Compare to normal bugs, a salmon fly is indeed a giant and can be the biggest bug in the water.

To anyone who wants to start a big fish fight, check out the content below to learn everything about the salmon fly. You will learn where and when to catch the salmon fly as bait. Also, if this insect is never seen in your area, a lure is recommended.

What Is Salmon Fly

Also, known as the stonefly, the salmon fly is a member of the Plecoptera family, technically, Pteronarcys californica will be the formal name.

They’re very easy to identify from other insects by their huge size. An adult salmon fly can grow up to 3 inches, nearly the size of a 10-year-old’s finger.

  • An adult is clearly orange with two pairs of big large wings, even longer than its abdomen but it’s never a good flyer.
  • For a nymph, it’s all brown and dark. The abdomen is covered by a segmented exoskeleton without no wings. On its leg joints, some orange can be easily seen.
Salmon Fly Nymph

Why Big Trout Like SalmonFly

After they finish the hatching process and come out, they will start to fly to find mates. During flying, they will fall on the water because their weak wings cannot carry the heavy body to travel far and stable. Any breeze would take them down.

Also, the other reason is that females will lay eggs in the water. When the eggs sink to the bottom of the water, the females get tired and start to struggle.

They will hit the water hard like a stone. Small fishes will be scared away while big fellows like trout will be seduced by the size and color (bright orange) of the feast. The struggle of an adult fly will drive the big fellows to crazy – making them even hungrier. Trout will dash to that energetic, fresh food.

Salmon Fly Adults

Where to Catch Salmon Fly

In the United States, the salmon fly is visible in most states in the west, from Washington to California where the Rocky Mountains pass by. However, salmon flies are only visible in some rivers of the west.

Habitat: Salmon Flies Live in Rocky and Rapid Rivers

The nymphs need to live on the bottom of rivers for 3 years. For the whole three years, stability of temperature, oxygen, food, and rocks is essential.

  • Only in warm springs, the adult flies will mate and lay eggs. Cold or hot water will kill the eggs and affect the lives of nymphs.
  • Nymphs need a lot of oxygen and food (leaves and debris), which are both brought by rapids.
  • Also, to get away from hunting, they need to hide among cobbles and rocks. And the spaces in the boulders help them latch on the bottom without being swept away.

As a result, swift and rocky rivers (and streams) will be where we find and catch flies. Calm waters like lakes should be ignored.

  • This is part of the reason that we can only find this large fly in the states where the Rocky Mountain passes and affects.

So, where can you find salmon flies?

  • Rivers that start on or pass by mountains or hills are the No.1 options.
  • A waterfall will be a bonus.
  • Also, will be river freeze? If yes, this may be too cold for the nymphs.
  • Check the rocks. Can you find lots of pebbles on the shores? If yes, that means the riverbed will most likely be covered by stones and rocks instead of mud.

When you find a river or stream as described, search on the shore. Check the vegetation and stones where they will hide and mate.

Man Fishing Trout with Salmon Fly

When to Catch Salmon Fly

Starting from early spring when the water temperature is close to 56 °F, the nymphs will swim to the shoreline and come out of the water to hatch. They will find trees, plants, and rocks and become pupas attached to the surface. Then, in a few days, they will hatch out and fly around to find partners to mate with.

That’s when you catch them.

Man Fishing Trout with Salmon Fly

Depending on the state and altitude of the river, the time of the hatching will be different. It’s hard to say for sure. So, the best way to locate the time is to ask the local experienced fishermen. They know the peak season and the best location.

Tip: You can search “Local salmon fly hatch near me” on Google. There’ll be discussions about the time and place.

What To Do When Salmon Fly Is Unavailable

For people who live in places that are far away from salmon fly habitats, the pictures of other fishermen holding big trout are such a pain in the belly. You can’t find any big, active, and colorful living bait like this around the local shores because of your location or time. In these cases, apply to artificial flies: the salmon fly lures.

You can:

Man Fishing Trout with Salmon Fly

How to Dress A Salmon Fly Manually

There’s this book “The Salmon Fly – How to Dress It and How to Use It”, written by George M. Kelson(1835-1920), a famous fishing editor of Land and Water ( A British magazine that started in 1862 till now).

It covers the tutorials for making 52 flies, including the materials, techniques of tying the lures as well as the patterns of all 52 files. Everything you need is in the book. Buy one and start to make your own salmon fly lure!

Ending Note:

Anglers, the best state to catch salmon fly is always Montana. There, rivers in almost the whole western half of the state are reported salmon fly witness. Others like California and Colorado are good, too.

By the way, when you want to go to a state where you can find salmon flies, always remember to get a local fishing license before you cast.


According to some scientific surveys and fishermen’s experience, the salmon fly is absolutely non-toxic. You can use it freely for fishing. Just don’t eat it though.

And most stone flies are non-toxic as well, maybe some or little of them will carry toxic but never deadly.

Yes, a salmon fly is a stone fly. There’re many kinds of stone flies in the world. And a salmon fly is nearly the largest one among all its fellows. All stone flies (including salmon flies) habitat around rocks. It can be the rocky riverbed or the shore that’s covered by peddles or stones.