Fly Fishing Hatches in South West Montana

Early Season Mid April – Mid May

Mid April (after the ice has left) and throughout May, our local waters provide great fishing, with little to no pressure on the rivers. Streamer fishing is the rule, as our trout are waking from their long winter slumbers and looking for some serious groceries; however there are several hatches worth mentioning. Especially into May, warm overcast days will bring our first hatches to the surface, and our first trout of the year to the top. When the weather is right, you can expect to see Blue Wings, Baetis, Grey and Green Drakes, and the possibility of a few Skwala Stones exist on the Big Hole. Nymphing should not be overlooked either – the trout are hungry right now and will be eating a variety of insects sub-surface – you can expect to see the better fishing from around 10-2 as our water temps encroach on the magic 50 degree mark.

Mid May to Early June (pre – runoff)

As our water temps stabilize around 50 degrees, mid May brings the Mothers Day Caddis hatch to all of our area rivers. This is the first real dense hatch we will see, and the trout know it. Pods of risers can be found in the slicker waters of the Big Hole that will stagger the imagination. Nymphing can be absolutely deadly throughout the day as these bugs are very active. The best dry action will usually be in the mid morning to early afternoon depending on the weather, although I have seen the hatch last all day long when the weather is right. It is not uncommon to see various mayflies scattered in pockets during this time – drakes, baetis, and blue wings can and will make a showing on cloudy days. The streamer fishing action is steady on cloudy days – when the big nocturnal Browns get a bit careless under the darker skies

Late May – Early June (post – runoff)

Once water flows stabilize from our snowmelt, the annual stonefly migration begins – providing good to excellent Nymphing before the actual “hatch”. There will be a window of a few days when the stones are VERY active subsurface, and its hard to get a trout to look at any other offering – usually when our visibility on the Big Hole returns to 2-3 feet. You might see a few adult stones in the willows, but the trout haven’t keyed in on them yet.

The Big Hole River Stonefly Hatch – (around the first two weeks of June)

Once the clarity improves to 3-4 feet, and the migration of the nymphs to the banks ebbs from a mass migration – the Salmonfly adults will become very evident. You might find the first one crawling on your shirt sleeve – or see one fluttering over the water. You might see a voracious slashing rise out of the corner of your eye – now you know. Get out the 2x leader and your favorite size 4 or 6 foamy, rubber legged creation and go to work. Dead drift it, skate it, twitch it, and for the love of god don’t set the hook too soon! These flies are big, and the trout has to get his mouth closed on it before you tighten up, or you may come back empty-handed.

This hatch will last anywhere from 1 – 3 weeks, depending on water levels and weather patterns, and although the big bugs steal the show – there will be lots of other trout food floating on top – its not uncommon to see 4 or 5 different mayflies and a few different colors of caddis in the foam lines.

The Madison River Salmonfly Hatch (Mid June – Mid July)

Shortly after the dust settles on the Big Hole, The Madison bugs will start their migration. Beginning on the lower river near Ennis, the Salmonfly hatch will typically migrate upstream for the next few weeks. Some hatches are longer than others, and denser – but this one is pretty reliable. The techniques and timing will be a replay of what happened on the Big Hole, with the trout keying in on the adults shortly after the first few hit the water. Mass upstream migrations of thousands of stoneflies can really be something to see. You will find however that the trout will respond better to imitations when the females have started hovering over the water dropping eggs, with the unfortunate few getting a little too close on occasion. Timing this hatch may require several visits to the area to really see it happen, but once you do, you will return every year for it.

The Beaverhead should not be overlooked during this timeframe – with a massive hatch of Caddis and PMD’sstealing the show. Good to great Nymphing can be had on this tail water throughout the day, with dry fly action being remarkable on cloudy days.

Summer in Montana – July, August, and September

Lower water levels and warmer temps require different techniques to get the trout to cooperate. Wading becomes very effective, as the long spring floats will be on the shelf for another year. Summer months bring good to great hatches of Trico’s to the Big Hole, Beaverhead and Missouri . There are still a few yellow sally stones kicking around on all of our rivers as well to add to the dry fly mix. As the summer nocturnal stones become active on the Big Hole and Madison, one can expect good to great Nymphing. Dry fly imitations will bring trout to the fly in the early morning and late evening, as these stones are nocturnal and not often seen during the heat of the day.

Hoppers and various terrestrials become available as the grasslands dry out and the bugs migrate to the lush green riverbanks. Typically, the terrestrial action increases into August, and peaks sometime early in September, depending on the weather patterns and harvest schedules of our areas hay meadows.

Montana – Mid September through October

Very limited dry fly action, yet great fishing – there may be a few resilient hoppers around, but the first few frosts will have our Browns thinking about spawning. Nymphing and pulling streamers will be the techniques of choice as these fish start building their carbs up for the long winter ahead. Swinging the fly will bring great results in the early hours of the morning and evening. As the Browns are pooling up, and competition for food increases, often the first fish out of a run will be the biggest.

Cool, crisp mornings and warm afternoons make this time of year very receptive to fishing “gentlemen’s hours”. The fall colors, the active wildlife and the great fishing make this my favorite time to be on the water. Most of the tourists have gone home, and you are very likely to be sharing the water with only the elk, deer and waterfowl.