What to Expect in Oregon in May

Importance by half-month
 Super    Major    Minor    Slight    None

Hatches are matched from Westfly's database of "standard" fly patterns.


Nymph

Size 16-20 Pheasant Tail, Hares Ear. Brown, brown-olive

Moderate runs, just below riffles: indicator, tight line, rising nymph

Emerger

Size 16-20 Sprout Midge, Film Critic, Hackle Stacker. Olive-brown body, gray wing

Flats, runs, backeddies: standard dry fly

Dun

Size 16-20 Sparkle Dun, Comparadun, Hairwing Dun. Olive-brown body, gray wing

Flats, runs, backeddies: standard dry fly

Spinner

Size 16-20 Diving Caddis, Soft Hackle. Dark body

runs, slowish riffles: surface swing

► You may find some blue-wings around early in the month, but most trout have switched to other fare.

Nymph

Size 16-18 Pheasant Tail, Hares Ear. Olive-brown

Riffles, flats, moderate runs: indicator, tight line, rising nymph, shallow nymph

Emerger

Size 16-18 Sprout Midge, Film Critic, Hackle Stacker. Pale yellow, light brown, or tan body; light wing

Flats, moderate runs, backeddies: standard dry fly

Dun

Size 16-18 Sparkle Dun, Hairwing Dun, Comparadun. Pale yellow, light brown, or tan body; light wing

Flats, moderate runs, backeddies: standard dry fly

► You may see some PMDs late this month on some rivers. However, you're more likely to see pale evening duns and mistake them for PMDs. Pale evening duns are larger and a more intense yellow than PMDs, and the wings are tan.

Emerger

Size 12-14 Soft Hackle, Film Critic, Hackle Stacker. Olive-brown, brown

Bankwater: surface swing

Dun

Size 12-14 Hairwing Dun, Comparadun, Sparkle Dun. Cream

Bankwater: standard dry fly

► Imitate with a size 12-14 Light Cahill, or yellow-bodied Sparkle Dun, or a local pattern that has an extended body.

► I've seen trout ignore big adult salmonflies in favor of hatching pale evening duns, so be prepared.

► These light colored mayflies are size 12-14, and trout like them. You might mistake them for a pale morning dun, but they are more intense in color than a PMD, the wings are tan, and they are larger. They are usually found hatching near riffly water

Emerger

Size 10-14 Soft Hackle, Quigley Cripple, Film Critic, Hackle Stacker. Tan to red-brown body, brown wing

Near riffles, flats: surface swing

Dun

Size 10-14 Sparkle Dun, Hairwing Dun, Comparadun. Tan to red-brown body, brown wing

Near riffles, flats: standard dry fly

► You may encounter hatches of March browns early in the month. If so, take a close look to make sure the trout actually care about them. There's a lot going on this month, and many trout will have switched their interest to other bugs.

► You may encounter hatches of March browns early in the month. If so, take a close look to make sure the trout actually care about them. There's a lot going on this month, and many trout will have switched their interest to other bugs.

► During the hatch, trout may be receptive to emerger patterns.

Pupa

Size 12-16 Soft Hackle, Deep Sparkle Pupa, . Body: green; Shroud: tan

Riffles, moderate-fast runs; just below these: surface swing, shallow nymph

Adult

Size 12-16 Goddard Caddis, X Caddis, Parachute Caddis, Elk Hair Caddis. Body: green, dark brown; Wing: brown, black

Egg-layer

Size 12-16 Diving Caddis, Soft Hackle. Body: brown; Wing: black

Riffles, current seams, backeddies below riffles: surface swing, shallow nymph, rising nymph

► Watch for afternoon and evening egg-laying adults.

► Grannoms (genus Brachycentrus)--aka the "Mother's Day Caddis"--are important on some Oregon rivers. Use a size 14 Sparkle Pupa or Deep Sparkle Pupa with a green body and a tan shroud before and during the hatch. Dead drift it near the bottom, then let it swing up to the surface. If you see trout feeding consistently just subsurface or making splashy rises, cast a Sparkle Pupa upstream-and-across and let it drift drag-free just under the surface.

Pupa

Size 16-18 , Deep Sparkle Pupa, Soft Hackle. Body: tan, green

Riffles, fast runs; just below these: indicator, tight line, shallow nymph

Adult

Bankwater near foilage: standard dry fly

Egg-layer

Size 16-18 Soft Hackle, Diving Caddis. Body: tan, olive-brown; Wing: dark brown, black

Riffles, seams, backeddies below riffles: surface swing, shallow nymph, rising nymph

Pupa

Size 12-18 Soft Hackle, , Deep Sparkle Pupa. Body: tan, green; Shroud: tan

Riffles, runs, just below riffles: surface swing, shallow nymph

Adult

Size 12-18 Goddard Caddis, X Caddis, Parachute Caddis, Elk Hair Caddis. Body: brown, green, dark gray; Wing: tan, brown

Nymph

Size 6-8 Kaufmanns Stonefly, Rubber Legs. Tan, yellow-tan

Riffles, moderate-fast runs; just below these: indicator, tight line

► Nymphs are most active at dawn and dusk, so that's when they are most likely to get knocked loose and drift in the current--and when trout will be waiting for them. But that doesn't mean you can't catch fish all day, either. It just tells you when you'll probably do best. Fish below riffles, among boulder fields, and through drop-offs.

Nymph

Size 6-10 Kaufmanns Stonefly, Rubber Legs. Black, chocolate brown

Riffles, moderate-fast runs; just below these: indicator, tight line

Adult

Bankwater near foilage: standard dry fly

► If you buy your salmonfly flies, buy them early in the month because the fly shops only stock-up once and won't re-order until next year. If you wait too long all you'll find are empty bins or flies that are the wrong size, pattern, etc.

► Just because you see adults flying around, don't assume trout have made the switch from nymphs to adults. It can take them several days to change their preference.

► Cast your dry fly near shore and just downstream or downwind from overhanging vegetation--especially in the afternoon when the bugs and the wind are at their most active. Another good spot is near rocks and places that concentrate the current.

► The key to the hatch is water temperature. When it gets around 52-53 degrees, the nymphs begin crawling to shore in earnest. Once out of the water, the adult emerges from the nymph, dries its wings, and flies to an alder tree where it utters the insect equivalent of "Hey, Baby, Baby." In their relentless pursuit of the opposite sex, adult stoneflies often fall or are blown out of the trees, land in the water, and are devoured by waiting trout, thus providing nourishment for fish, sport for anglers, and a moral lesson for us all.

► Salmonfly nymphs are most active at dawn and dusk, so that's when they are most likely to get knocked loose and drift in the current--and when trout will be waiting for them. But that doesn't mean you can't catch fish all day, either. It just tells you when you'll probably do best. Fish below riffles, among boulder fields, and through drop-offs.

Pupa

Size 10-22 Chans Chironomid Pupa, Zebra Midge. Black, gray, olive, red, creams, browns

Adult

Size 10-22 Griffiths Gnat, Sprout Midge. Black, gray, olive, red, creams, browns

► Midges are fading in importance this month because trout have so many other bugs to choose from. But it's still good to be prepared in case of a hatch that sparks the attention of the fish.

Trout


► If a river is slightly colored from snow melt or rain, you'll probably do best with nymphs, and those nymphs will usually work best when drifted near the bank. If the river is high and into the grassy banks, you may pick up trout on nymphs there as well.

Steelhead


► The winter steelhead run is over. A few early summer steelhead will be in some river this month. If the water is cold, you'll still need standard winter steelhead swinging flies and traditional tactics. If the water temperature is over 50 degrees, you might get by with standard summer steelhead swinging flies. In general, however, this is not a good month for steelheading.

General


► Melting snow will raise rivers and keep them cool, so watch the river level gages carefully. If you see a sudden large increase, you can figure fishing is going to be poor on that river until the flows stabilize or drop significantly.

► 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.

Importance by half-month
 Super    Major    Minor    Slight    None

Hatches are matched from Westfly's database of "standard" fly patterns.


Nymph

Size 14-16 Pheasant Tail. Brown

Emerger

Size 14-16 Quigley Cripple, Film Critic, Hackle Stacker. Gray to tan

Lakes, slow water: chuck-and-sit

Dun

Size 14-16 Sparkle Dun, Hairwing Dun, Adams, Comparadun. Gray to tan

Lakes, slow water: chuck-and-sit

Spinner

Size 14-16 Rusty Spinner. Tan to brown

Lakes, slow water: chuck-and-sit

► During a hatch, use a Callibaetis Cripple or Sparkle Dun with a chuck-and-sit presentation.

► Hatches will begin in earnest on many lakes this month. They usually occur late-morning to mid-afternoon.

► Trout will feed on nymphs for a couple of hours before the hatch. Take advantage of this and cast a nymph pattern, then retrieve it slooooooowly; use an intermediate line with a long leader. A Flashback Pheasant Tail, size 14-16, should work quite well. In my experience, a Flashback PT outfishes a regular PT by 3-to-1 during this hatch. The reason is that many nymphs develop a shiny back just before they hatch, and trout look for this feature.

Pupa

Size 6-10 , Deep Sparkle Pupa, Soft Hackle. Body: Ginger, brown

Lakes; backwaters and slow sections of rivers: slow retrieve, verticle retrieve

Adult

Size 4-10 Parachute Caddis, X Caddis, Elk Hair Caddis. Ginger, brown

Lakes; backwaters and slow sections of rivers: chuck-and-sit

Nymph

Size 8-12 Marabou Damsel. Olive, yellow-olive, browns, greens

Lakes near submerged vegetation: count-down-and-retrieve, slow retrieve, wind drift

► The standard damselfly retrieve is to pull two inches of line in two seconds, pause two seconds, then repeat. Use an intermediate line; damselfly nymphs move in the top inch or so of water. That said, you can do pretty well just trolling a damsel nymph as you slowly and steadily kick around the lake in your float tube or 'toon.

► Nymphs should become effective as the water warms up. Imitations work best near weedbeds.

Pupa

Size 10-22 Chans Chironomid Pupa, Zebra Midge. Black, gray, olive, red, creams, browns

Adult

Size 10-22 Griffiths Gnat, Sprout Midge. Black, gray, olive, red, creams, browns

► In many desert lakes, there is a very large midge that hatches in early May and is preferred by trout. It is matched by a black-bodied, silver or white ribbed pupa pattern in size 10 or 12; the pattern MUST be slender.

► During a midge hatch, the static midge tactic usually 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.

► You might see hatches of different species throughout the day and evening. Each may require a slightly different fly.

Adult

Size 2-10 Woolly Bugger, Bunny Leech, Hale Bopp Leech, Possie Bugger. Black, browns, olives

Lakes; backwaters and slow sections of rivers: count-down-and-retrieve, slow retrieve, wind drift

► When fishing leech imitations or other streamers in the spring, "low and slow" are the watchwords. The colder the water, the slower you should present the fly. Keep your fly near the bottom (in water that is less than eight or ten feet deep) and retrieve it very slowly.

► It's hard to go too far wrong with a leech pattern or a Woolly Bugger on a clear intermediate line.

Adult

Size 2-8 Muddler, Woolly Bugger, Clouser Minnow, Possie Bugger. Browns, olives, silver, greens

Lakes; rivers over gravel and cobble, undercut banks: count-down-and-retrieve, slow retrieve, wind drift, deep swing

Trout


► Non-wild hold-over rainbow trout in lakes with no spawning access may be stacked around rocky, gravelly areas. On some lakes, that means the boat ramp.

► It's spawning season for rainbow trout. You'll find them in or not far from the inlet and outlet creeks, if they are wild fish. If you respect the fish and value the future of your sport, you'll leave them alone until they've spawned and recovered.

► This can be a good month to visit Willamette Valley or coastal lakes. They warm up sooner than their eastside brethren.

► Expect to find trout in the shallower areas because they warm up first and are more likely to have food. Sometimes you can pick up fish at deeper levels, but in general you're better off to concentrate on the margins of the lakes and near weed beds.

Wind drifting is an effective spring strategy 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.

General


► Eastside lakes that are technically open all year may still be iced over or snow may block access to them. Or not. It depends on what kind of winter we had.