Quick answer: April is the most underrated month on the Missoula calendar. Early in the month the rivers are still clear, the skwalas keep going into mid-April and sometimes to the end of the month depending on the weather, blue winged olives hatch on cloudy afternoons, and the western March browns hit their stride, especially on the Clark Fork. As snowmelt starts to color the rivers in the second half of the month, streamer fishing turns on. Afternoons can push past 60 and even into the 70s, mornings are still cold, and the weather can do anything.

For the first part of April, before snowmelt clouds the rivers, the dry fly fishing is as good as it gets around here. Here is what to expect.

What is hatching in April?

Early April is spring at its best, and the bugs are the reason:

Skwalas are still bringing fish up, and as the hatch goes on the fish get pickier about the biggest patterns, so your guide will often size the fly down.
Blue winged olives hatch on cloudy afternoons and pull steady risers to the surface.
Western March browns are the story of the month. They are stronger in April than in March, and they will come off without sun as the water warms. On the Clark Fork the March brown hatch often really arrives in April, and March and April together are a great window on that river.
Mother’s Day caddis start to show late in the month, and they peak in May.

The trout are as active as they have been since fall. Fish that have been undisturbed all winter respond well to a good drift, and with the March browns the rule is simple: they will take most anything close if the drift is right.

When does runoff start, and what does it change?

Snowmelt usually starts in late April. River levels begin to fluctuate in the middle to second half of the month, and the water picks up color as the mountains let go. Visibility can drop and then improve again within a couple of days, so an April week is rarely all one thing.

That is not bad news. As the rivers rise and dirty up, streamer fishing becomes absolutely prime time. Stripping a big fly through the right water in rising April flows is one of the best ways to move a large trout all year. Your guide watches the gauges and the water color every morning and picks the river that gives you the best day.

Which river fishes best in April?

Early in the month the Clark Fork and the Bitterroot are both fishing well, and as runoff builds your guide follows whichever one is holding clearer water that week. The Blackfoot is the last of the three to come into its own. It runs cold and usually waits for June.

Another April habit that pays: fish the water other people skip. Walk a little farther, or float a less-traveled section. With the fish this willing and the crowds this thin, a little effort finds a lot of undisturbed trout.

What is an April day like?

Later starts than summer. The bugs and the fish get going from late morning into the afternoon, so a typical day is a relaxed morning, dry flies when the March browns or olives come off, and streamers whenever the water is up. Weather in western Montana in April does what it wants: sun, clouds, wind, and a snow squall can all show up in one afternoon, and the cloudy days are often the best fishing days.

What should you wear in April?

Layers, and a rain jacket no matter the forecast. A warm base layer and a fleece or puffy for the morning, a waterproof shell, and waders if you own them, since the water is still cold. If you do not own waders, tell us when you book and we can lend you a pair on the cold days, or rent a set from Rent Waders (rentwaders.com), a Missoula company that delivers to our shop. The full list is in our What to Wear post.

Why fish April with a guide?

April is a month of change, and the fishing follows the water. One river can be clear and rising while another is already off color, and the right call in the morning can be the wrong one by afternoon. Your guide tracks the flows and the color on every river and puts you where the fish can see your fly. You pick your dates, we pick the water, and when one river blows out we move to the one that is still fishing.

Common questions about April in Missoula

Is April better than March? For dry flies, often yes: more bugs, more willing fish, and warmer afternoons. March has the edge on quiet water and low, clear flows all month.

Will runoff ruin my trip? Early April, almost never. Late April, sometimes on one river, rarely on all of them. That is exactly why we do not lock you into a river when you book.

Can you fish dry flies in April? Yes, and it can be excellent, especially on cloudy afternoons when the olives and March browns come off.

Is it crowded? No. April is well before the summer rush. Weekends see a few more boats than weekdays, but nothing like June.

How far ahead should I book? A few weeks is usually enough for April, though the clear-water stretch early in the month fills up as word gets around.