Hatches divided by half-month.
Super Major Minor Slight None
|Pale morning dun|
|Pale evening dun|
|Small black stonefly|
Spring weather governs April fishing: too warm, and snow will melt and muddy the rivers; too cold and the trout won't be very active and hatches will be depressed or delayed. Cool and showery, with a big storm about once every ten days--that's my fondest hope for April.
Trout. Blue-winged olives continue to be a major factor for trout anglers on rivers. They'll be important through early May, although other hatches will begin to overshadow them. Size 18-22 patterns such as Sparkle Duns and Baetis Cripples work well during hatches, as do Parachute Baetis and small Comparaduns . In general, the best action will be 2:00 p.m. to 4:00 p.m. If you want a little more fishing, tie on a size 18 Gold-Ribbed Hares Ear or a Pheasant Tail and drift it near the bottom during the pre-noon hours. The best way to get these small flies down on the bottom is to pinch a split shot onto the leader or to use a tandem fly rig with a heavy fly such as a Rubber Legs on the point and the small fly on a dropper about 12 inches above it.
Runs of slow to moderate speed are best for the blue-winged olive nymphs, but the dry flies work best in backeddies and along current seams. Post-hatch, try a Diving Baetis to pick up trout feeding on egg-laying females (see Hidden Adults and Go Below for BWO).
March brown mayfly hatches will continue on many rivers, especially those that are east of the Cascade crest. Carry size 10 and 12 Comparaduns , CDC Cripples or similar patterns. Check the naturals for color; some hatches east of the Cascade crest are pale brown or cream on the underside, while Willamette Valley hatches can be reddish-brown underneath. In all cases, the underside (the part trout see most) is lighter than the top. Look for feeding fish in slow-to-moderate runs that are near riffles. Note that March brown nymphs migrate from riffly water to slower water before they hatch. That migration could be upstream, downstream, or across stream. So you don't just find duns hatching below riffles; you can find them below, above, or near riffles. You can also find drifting duns in backeddies and quiet water below the hatch locations.
Another mayfly you'll find on some rivers this month is the first round of the mahogany duns . The nymphs migrate to slow water along the margins of the river before they hatch. Because the hatch is in slow water, you need to avoid blind casting. Instead, wait until a trout rises, then cast upstream of that spot. If you cast blindly you risk putting the fish down before you hook any. For more on this hatch, see Mahogany Duns.
Caddis are very important this month and next. Many rivers have large populations of green caddis (genus Rhyacophila) and spotted caddis (genus Hydropsyche). The larvae often drift in the current and are taken by trout. Princes , Green Rock Worms , and Net Builders are good fly choices, but you should take a look at Caddis Larvae--Part I before casting imitations.
Expect occasional hatches of green caddis around 2-4 p.m. (daylight time) in soft water below riffles. A dark Elk Hair Caddis in sizes 12-14 can work well, but emerger patterns such as a Soft Hackle or Sparkle Pupa are usually better. Emergers should be presented just subsurface, either on a dead drift or with a wet-fly swing. The green caddis will hatch through April and part of May, then come back again in fall.
Saddle-case caddis (genus Glossosoma) and weedy water caddis (genus Amiocentrus) also hatch throughout April in the afternoon, and some grannoms (genus Brachycentrus) may show up near the end of April.
Here's a summary of sizes and colors for April's most common adult caddis:
- Green caddis: size 12-14; dark olive body, gray wing
- Spotted caddis: size 12-14; brown to tan body, tan wing
- Saddle-case caddis: size 18-20; tan body, dark wing
- Grannom: size 10-14; dark brown body, tan wing
- Weedy Water: size 16-18; dark olive body, dark wing
- McKenzie Caddis: size 12; bluish-green body
Many caddis species lay eggs by swimming or crawling underwater, and trout often take them. Use a wet fly such as a Soft Hackle or a Diving Caddis in the sizes listed above. Caddis get darker when ready to lay eggs, so use darker versions of the listed colors.
Stoneflies are the other game in town. Very few little brown stoneflies (winter stones) are left, but trout will begin picking up the large salmonfly and golden stonefly nymphs. Look for little yellow stoneflies on some rivers; see Little Yellow Stoneflies for details about fishing this hatch. The spring stonefly, or Skwala , is a member of the little yellow stone group, although it isn't especially little--or yellow. It's a kind of gray-olive color, about size 8-10. Carry some Stimulators (an olive body with a hint of yellow around the thorax) or Bitterroot Olive Stoneflies in that size.
Above all, remember that rainbow trout are now spawning. Avoid spawning beds (redds). They show up as clear patches in the gravel. Don't walk through them, anchor over them, or target trout that are on them.
Flexibility and preparedness are the watchwords for spring fishing. Be prepared for any kind of weather and don't rely on any one hatch.
Steelhead. April is the end of winter steelheading. For the first half of the month, you can still find fish in the coastal rivers, upper Rogue, North Umpqua, and other rivers with healthy populations of wild, native steelhead. You will also find large numbers of spawned-out "downstreamers" headed for the ocean. The downstreamers are more likely to be in slower, quieter water than their fresher breathern.
Hatches divided by half-month.
Super Major Minor Slight None
Spring fishing in lakes is mostly a midge and streamer experience. During a midge hatch, the static midge tactic works well. If the hatch is during the bright part of the day, however, you may do better with the deep midge tactic because trout can be reluctant to come to the surface.
Streamers such as Woolly Buggers are effective, too. The colder the water, the slower you should present the fly. "Low and slow" are the watchwords for spring streamer fishing: keep your fly near the bottom (in water that is less than eight or ten feet deep) and retrieve it very slowly.
Another effective streamer strategy is wind drifting. This works well if the wind is not too strong. On the other hand, you need something more than dead calm or your fly isn't going to move. Done right, wind drifting covers the water well and feels like cheating.
Damselfly nymphs should become effective as the water warms up. Imitations work best near weedbeds.
Shallow areas are often the best places to look for trout in the spring. Those are the first parts of the lakes to warm up, and therefore they get more of the insect activity.
If you're fishing a lake where the ice is receding, a good strategy is to cast a midge pupa to the edge of the ice sheet. This works well because midge pupae will rise the surface and hit the ice. Then they'll wriggle out to where there is open water. This concentrates food along the edge of the ice sheet, and that is where feeding trout will be looking for a meal.
Be prepared for sudden weather changes and storms when fishing a lake in the spring.
Coastal bass lakes such as Tenmile and Siltcoos should turn on in April if we get some warm weather.