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Chasing the Salmonfly Hatch on the Big Hole River

Every angler waits, and waits, and waits for hatches to occur.  The most famed hatch in Southwest Montana worth the wait is the Big Hole River Salmonfly hatch.  It is every fly fisher’s dream to throw# 4 dry flies to the bank and watch 5 pound browns rise with a vengeance to eat your fly.  This is truly an exciting time to be fly fishing the Big Hole River.  Usually the river is raging with high water as this hatch occurs.  Typically as the Big Hole is coming down from runoff you have your best dry fly fishing.  Anglers have to be on their game as your boat is rolling down the river and you are trying to get your dry flies as close to the banks and willows as possible to get an eat from a hungry trout.

Big Hole River Salmonfly Hatch Timing

The Big Hole River Salmonfly hatch typically occurs from June 15th-July1st.  What makes this hatch unique to the Big Hole River is the length of the river it takes place on and the abundance of flies hatching.  You can find this hatch first on the lower river near Glen, then it works it’s way up the river to East bank.  This is about 80 miles of floatable river that this hatch is occurring on.  The Salmonfly hatch starts on the lower river since the water starts to warm first there.  A lot of people refer to “chasing the hatch” when they talk about Salmonflies.   You will find fly fishing guides in the early mornings and late evenings looking for shucks on the willows and bridges to see if Salmonflies hatched during the night.

The Big Hole River Salmonfly hatch typically occurs from June 15-July1st.  What makes this hatch unique to the Big Hole River is the length of the river it takes place on and the abundance of flies hatching.  You can find this hatch first on the lower river near Glen, then it works it’s way up the river to East bank.  This is about 80 miles of floatable river that this hatch is occurring on.  The Salmonfly hatch starts on the lower river since the water starts to warm first there.  A lot of people refer to “chasing the hatch” when they talk about Salmonflies.   You will find fly fishing guides in the early mornings and late evenings looking for shucks on the willows and bridges to see if Salmonflies hatched during the night.

Entomology of the Big Hole River Salmonfly

The Salmonfly is a member of the Stonefly family.  There are three stages of the Salmonfly: egg, nymph, and adult.  These creatures of nature will live for 2 – 4 years as a nymph before they become an adult.   Several factors need to occur before these flies emerge as adults.  The Salmonfly needs a constant water temperature in the 55-degree range for a steady period before they hatch.   When conditions are just right these nymphs swim towards the bank to hatch.   Salmonflies like to crawl onto willows and down trees on the banks to then shed their shucks and become an adult.  Salmonflies will live for up to 7 days as an adult, with one thing in mind to breed and then lay eggs back into the water.  You will find these flies most susceptible to trout as wind blows them off willows onto the water, or the females are flying over the water dropping their eggs into the water. These flies struggling on the surface while the females drop eggs and trout are waiting to slurp them up.

The Salmonfly is a member of the Stonefly family.  There are three stages of the Salmonfly: egg, nymph, and adult.  These creatures of nature will live for 2 – 4 years as a nymph before they become an adult.   Several factors need to occur before these flies emerge as adults.  The Salmonfly needs a constant water temperature in the 55-degree range for a steady period before they hatch.   When conditions are just right these nymphs swim towards the bank to hatch.   Salmonflies like to crawl onto willows and down trees on the banks to then shed their shucks and become an adult.  Salmonflies will live for up to 7 days as an adult, with one thing in mind to breed and then lay eggs back into the water.  You will find these flies most susceptible to trout as wind blows them off willows onto the water, or the females are flying over the water dropping their eggs into the water. These flies struggling on the surface while the females drop eggs and trout are waiting to slurp them up.  

Trout pack on the pounds during this hatch.  It is not uncommon to catch a trout and see Salmonflies crawling out of their gills.  Besides the great dry fly activity.  The other time period that Salmonflies are easy trout food is when they are moving towards the bank to hatch.  Nymphing large #4 Stone Fly nymphs are very effective just before the hatch occurs. 

Flies for the Big Hole River Salmon Fly Hatch

The Sunrise Fly Shop has a selection of hand-tied Salmonflies that are proven patterns that work on the Big Hole River.  The Unabomber Salmonfly is a must have if you are on the Big Hole River.  For more information on fly fishing the

Salmonfly hatch on the Big Hole River , contact the Sunrise Fly Shop at info@sunriseflyshop.com.