The Salmon Fly Hatch is one of the most epic hatches in Western waters. These large stoneflies emerge from late May into July depending on the watershed elevation and water temperatures. This is a hatch you want to put on your bucket list. You can easily have 30-40 fish days when trout key in on these insects.



When and where do they hatch

American Salmonflies are the largest North American stonefly. They have been observed up to three inches (3”) long. They are huge. The Salmonfly hatch occurs from California to British Columbia and as far east as Wyoming.

They are extremely sensitive to pollution. If the water is laced with chemicals, the larvae will die. Hence, the sight of many adults means the water source and the ecosystem it supports are healthy and clean. For fishermen, the sight of American Salmonflies is most welcome.

Timing the hatch can be tricky. It’s dependent on water temps. This means the snow pack will greatly influence timing. The more snow, the longer the run off of the snow melt. A good rule of thumb is to start looking around memorial day. Other factors influence that progression of the hatch including day length and water temperature. In general, salmonflies hatch when peak water temperatures are close 56 degrees F.

One of my favorite trips is to hit Missoula in mid June. Close by you have The Blackfoot, Bitterroot, and Clark Fork rivers. Rock Creek is a nice spot as well. One of these watersheds will have Salmonflies coming off.

Understanding hatch progression

Salmonflies will spend 4 years underwater. They will then move to the shoreline and climb up rocks and bushes to emerge. Want to know if there are some salmonflies coming off? Shake some shoreline bushes, if they are there, they’ll drop out. Hard to miss. The bugs start to hatch generally in the lower areas of the river and move progressively up river. and accordingly move upriver. Also look for their shucks. Another good tell tale sign.

This is a big fish hatch. In general, if you want your gest chances of catching a 24”-30” fish, this is the hatch. Yes, you can catch big fish on small flies. However, in general, big fish target big meals. Salmonflies are a big giant cowboy ribeye to trout.


Use different patterns

I always make sure I have a large assortment of patterns and sizes. Every year, it seems like the trout key in on one. The salmonfly hatch is the perfect hatch for fishing a hopper-dropper rig. The dry patterns are large and can handle just about any nymph you want to drop off it. Have different salmon dry flies in different sizes and patterns. At RiverBum, we carry options like The Triple Decker, Sofa Pillow, Trinas Dog Puke and King Kong.

If you get a chance to hit this epic hatch, take it! It could be the trip of a lifetime.


About the Company:

This article is written by Ricky Martin, Pro Staff at RiverBum. RiverBum offers premium quality flies and gear at highly competitive prices. A family owned US business, RiverBum promotes the sport of fly fishing to all folks from every walk of life.