Pro Tips: 5 Keys to Fishing the Salmonfly Hatch on the Madison

Written by: Doug Casey, Montana Angler Fly Fishing

Each year, anglers from around the world head for Montana to see if they can hit the salmonfly hatch.
Photos by Doug Casey

The annual salmonfly hatch on Montana’s Madison River is one of fly fishing’s most storied and anticipated events. Salmonfly time is hands-down your best shot at landing a true trophy trout on a dry fly. The sight of a three-inch-long insect splashing about the surface is enough to draw even the largest fish from its deep, dark lair. Anglers from across the country descend upon Ennis, Montana in late June to try their luck, as southwestern Montana becomes awash in salmonfly fever. However, this hatch can be as fickle as it is famous, so let’s take a look at some tips to increase your odds for success on the Madison.

Tip #1: Timing is Everything
For the visiting angler or anyone who can’t be on the river at a moment’s notice, timing the hatch can be the toughest part. Generally speaking, the two-week window from June 20 to July 4 is when the hatch should fall. The bugs typically appear in the town of Ennis around the 20th, and by the 25th the hatch has exploded throughout the float section up to Lyons Bridge. These dates are just general guidelines, and both weather and water conditions can lead to early or late emergences of the big bugs. If Montana is experiencing a big snow year or an unseasonably cold early summer, you can plan on things being pushed back a bit. Drought years and warm weather have the opposite effect. Things can change on the river at a moment’s notice, and even the best-laid plans can go awry, but using information on snowpack, weather, and historical trends will give you the best chance to hit the hatch.

There’s no confusing a salmonlfy with any other bug in June. It’s a big one.

Tip # 2: Location, Location, Location
The Madison is large river system, running over 180 miles from its headwaters in Yellowstone National Park down to its mouth at the headwaters of the Missouri in Three Forks, Montana. While most of this run sees at least a smattering of the bugs, the heaviest hatch occurs in the reach between Quake Lake and Ennis Lake. This stretch is referred to locally as the “Upper” Madison or the “50 Mile Riffle.” For the wade fisherman, the stretch between Quake Lake and Lyons Bridge is a good bet because of ample public access and regulations that prohibit fishing from boats in this reach. Lyons Bridge down to the town of Ennis is dominated by float fishermen in drift boats and rafts, although public access for wading is available at various intervals.

Banging the banks above Ruby Rocks.

Tip # 3: Avoid the Heaviest Part of the Hatch
While this sounds counterintuitive, you actually want to avoid the bulk of the hatch for optimal fishing. There are only so many giant stoneflies that will fit in a trout’s stomach, and the fish will gorge themselves to the point where they will stop feeding. It is not uncommon to land fish whose stomachs are visibly distended. However, when these fish are done digesting, they will be back on the feed and certainly remember what a salmonfly looks like, even if the majority of the hatch has moved on upriver. This is especially true for the dry-fly fishing, which will be best anywhere from 3 to 7 days behind the hatch. If you can get out ahead of the main hatch, nymphing is the way to go, as the salmonfly nymphs will be very active underwater in preparation for hatching. The hard part is determining where exactly the bulk of the hatch is at any given time. Hopefully you will be on the water to determine this for yourself, but otherwise local fly shops and guides keep close tabs on the bugs.

Tip # 4: Don’t Focus Solely on the Banks
Whether floating or wading, the natural inclination for anglers during the hatch is to pound the banks. After all, the bugs are thick in the bankside willows and the water is up, naturally pushing fish towards the shore. However, two factors on the Madison make ignoring the rest of the river a mistake. First, the Madison has an incredible amount of midstream structure, primarily in the form of large boulders. Second, the hatch brings heavy pressure to the river and a steady stream of anglers pounding the banks can actually draw a reaction from the fish and push them off. That is not to say that bank fishing isn’t productive, as sometimes it is incredibly so. Just avoid approaching the river with a one-track mind and don’t be afraid to change things up.

An angler wades the Slide section of the Upper Madison.

Tip # 5: Fish a Two-Dry Tandem Rig
When I am dry-fly fishing during the salmonfly hatch, I always fish with a second, smaller dry fly as a dropper behind my big bug. The salmonflies aren’t the only bug hatching in late June, with abundant caddisflies and smaller stoneflies available to fish, as well. Also, the fish will sometimes become suspicious after seeing hundreds of fake size 2 flies. I have seen many instances where a fish rises to a salmonfly pattern only to shun it in favor of a size 12 attractor that was trailing behind. I like to keep my droppers short when fishing double dry, so have your second fly about a foot to 18 inches behind. When you are bragging to your buddies and showing off photos of your big fish at the end of the day, which dry fly it ate isn’t going to matter, so add a dropper and double your chances. [Editor’s Note: Click here for a lesson on tying and fishing tandem rigs.]

Doug Casey is a guide for Montana Angler Fly Fishing, an Orvis-Endorsed Fly-Fishing Expedition in Bozeman, Montana.

6 thoughts on “Pro Tips: 5 Keys to Fishing the Salmonfly Hatch on the Madison”

  1. I tried to catch them once on the Madison. All the Anglers were lining the banks at Lyons Bridge in the evening. Not a bug showed. When I was on the Yellowstone one afternoon about ten different Salmon flies launched across the river. Each one was caught mid flight before they got acrossed the river by Robins. So much for the hatch.

    1. Salmon flies were still going off on the upper end of the West Fork Bitterroot in July last year. All the local fly shops said the salmon fly hatch was over, but there they were. Banged quite a few fish.

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