Montana Rivers


What to Expect in April

Note: This What-To-Expect is from Westfly's Legacy pages and may not accurately reflect the current fishing at this venue.
There are only two things that's certain in April: first, that weather conditions will govern fishing this month; second, no one can reliably predict the weather more than a couple of days in advance.

Spring fishing can be good, miserable, or indifferent--sometimes all on the same day. Warm conditions, or even cool weather with some overcast, can be good for fishing. Cold, clear weather will depress hatches and slow trout down. If it's too warm, mountain snow will melt and muddy the rivers. So keep a close eye on Westfly's river level graphs and weather pages; avoid fishing when the flows spike upwards or the temperature trend is on the cold side

On many rivers and creeks, blue-winged olive mayflies will be hatching in the early afternoon. The hatch depends on water temperature, so it will start later on some rivers than others. While hatches can be sporadic and of unpredictable intensity, nymphs are commonly found in the drift and represent one of the best fishing opportunities. Dead drift a size-18 Pheasant Tail, Brassie, or CDC Bubble Brassie near the bottom using either trout indicator or tight line tactics. Slower runs and the insides of current seams are often the best places. On larger rivers, backeddies can be very productive.

During hatches of blue-winged olives, use a Sparkle Dun, Baetis Cripple, Parachute Baetis, Comparadun, or similar size 18 dry fly. Female blue-winged olives often lay eggs underwater, and this can be an excellent fly fishing opportunity.

March browns are another important hatch this month. Not every river hosts them in large numbers, but they make for great fishing when they occur. Nymphing is so-so, but fishing during the hatch can be outstanding. Hatches start around 1:30 p.m. (daylight time) and can last an hour and a half. CDC Cripples, Comparaduns, and extended body patterns can all be effective. March brown spinner falls are rarely significant.

Skwala stoneflies are still available on some rivers, but they will fade about mid-month. Since trout are slow-to-change conservatives, they will continue to take big dry fly imitations even when the adults have mostly vanished from the scene. A size 8 Bitterroot Olive Stonefly or dirty-olive Stimulator can take trout.

Midges are also important this month. Generic larva and pupa patterns, such as Serendipities, Brassies, CDC Bubble Brassies, Copper Johns, and Blood Midges, can be productive when dead-drifted near the bottom. For adult patterns, carry Griffiths Gnats and/or Sprout Midges. The latter is harder to tie, but is very effective on slow water and spring creeks.

April is also a good time to ply a streamer, especially as things start to warm up.

Rainbow trout will be spawning this month, so watch where you wade or anchor. If you see gravel that has been scraped clean of algae, it's probably a redd and you should avoid it. Also, don't fish over spawning trout--just leave them alone.


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