HENRY'S FORK ANGLERS

Characteristics

Adults have two wings, a slender body and size long legs. Pupae have thin elongated, well-segmented abdomens with a short robust thorax. Most species require only a few weeks to mature. Midges have a complete life cycle consisting of an egg, larva, pupa, and adult. The pupa is far more important than the adult or larva. The colors vary widely. The most common colors are olive, brown, tan, gray, and red.

Timing

Midges emerge year-round. The pupae emerge in the morning and evening hours. During cool weather they often emerge throughout the day.

Habitat

All water types. Many species prefer slow water rich in aquatic growth.

Comments

Best midge fishing on the rivers is during the late fall, winter and early spring. Midge fishing is especially effective on Hebgen Lake and other lakes in the region from ice-out until early July.

Patterns (Sizes 12 - 24)

Griffith's Gnat, Midge Pupa, Stillborn Midge, Miracle Midge, Suspended Midge, CDC Midge Adult, Tungsten Zebra Midge

Characteristics

Two tails. Light to medium olive/gray body with light to medium gray wings.

Timing

Mid-March through early May during afternoon hours and in the mid-summer around dusk & September through October during afternoon hours

Habitat

Widespread on most sections of the Henry's Fork, Madison, Firehole, South Fork of the Snake, and other local rivers and tributaries.

Comments

Many species are multi-brood, meaning a species may produce two or more broods during the calendar year. They are classified as swimmer nymphs. The most important species emerge in the spring and again in the fall. These mayflies produce exceptional dry fly fishing during these periods. Egg laying spinners often crawl under the water to oviposit their eggs.

Patterns (Sizes 18, 20, & 22)

Pheasant Tail Nymph, Halfback Emerger, CDC Emerger, Paracripple, BWO Soft Hackle, BWO Nohackle, Sparkle Dun, Thorax, and Parachute Adams

Characteristics

Two tails. Dark gray wings with strong dark mottling. Body is dark olive brown to purplish black.

Timing

Late spring from mid-April through early June. Duns emerge during mid-morning hours. Spinners fall in the evenings.

Habitat

Medium to fast water with gravel or rocky bottom. Very common on most sections of the Henry's Fork. Late season species are also common on the Madison, Gallatin, and some waters in Yellowstone Park.

Comments

March Browns provide exceptional dry fly fishing on the Henry's Fork in May and early June. They are classified as clinger nymphs. Transformation from the nymph to the dun usually takes place under the water. Therefore, a soft hackle emerger fished deep can often bring good results. During cooler weather the duns will stay on the surface long enough to provide good dry fly action.

Patterns (Sizes 12, 14, & 16)

Pheasant Tail Nymph, Pheasant Tail Soft Hackle, March Brown Emerger, Quill Gordon, Slate Olive Thorax, Slate Olive Nohackle

Characteristics

Sometimes known as the "Mother's Day Caddis" the common Grannom is a very important hatch in the pre-runoff period in April and May on the Henry's Fork, South Fork, and other local wateres. These caddis are second only to the Spotted Sedge in importance for fly-fishers. The case making larvae are a very important food source for wintering trout. Another species produces very good fishing on the Henry's Fork, Madison, Yellowstone and other waters during late summer.

Timing

April and May and August through early September. Emergence occurs in the afternoon and early evening. Egg laying frequently coincides with the emergence.

Habitat

All water types. Larvae build square cases. They thrive on gravel, rocks and aquatic vegetation.

Comments

Pupae can drift long distances while struggling to escape the pupal shuck. Males are one size smaller than females. The emergence often produces explosive rises from trout that are hungry after a long winter. Best technique is to use a pupa as a dropper from a dry fly.

Patterns (Sizes 14, 16, & 18)

Olive Cased Caddis, Olive or Dark Gray Emergent Sparkle Pupa, Olive Partridge Pupa, Olive Spent Partridge Caddis, Olive X-Caddis, Olive E-Z Caddis, Hemingway Caddis

Characteristics

These are huge insects. The adults are dark charcoal with dark orange thoraxes and underbellies. The nymphs vary from dark mahogany brown to black. They take 3 to 4 years to mature from egg to adult. The nymphs concentrate near the bank and crawl out to emerge. Emergence is specifically concentrated and usually moves upriver a mile or so a day. The egg-laying adults fly clumsily over the water and many of them end up on the water providing explosive dry fly fishing.

Timing

Henry's Fork - May 20 through June 10

Madison River - June 20 through July 5

South Fork - June 20 through July 5

Habitat

Medium to fast, oxygen rich water with rocks and boulders

Comments

Nymphs provide norishment to trout on a year-round basis. There are usually 2 or 3 age classes of nymphs in the water at the same time. Trout can get totally gourged on the nymphs just prior to emergence. Trout can quickly get their fill of adults. The best tactic is to try to work the water upstream from the main emergence with nymphs. The best dry fly fishing normally occurs after the peak of the emergence is over so that trout are more focused on adults.

Patterns (Sizes 4 & 6)

Black or Brown Rubberlegs Nymph, Henry's Fork Salmonfly, Rouge Salmonfly, South Fork Secret, Foam Salmonfly

Characteristics

These large stoneflies are similar in appearance to their larger Salmonfly cousins except they are a couple of hook sizes smaller and they are lighter in color. They are a dark golden amber with a lighter underbelly. The most common species emerge along with or just after the Salmonflies. Their emergence usually covers a longer period. Another species emerges on the South Fork of the Snake in late summer and early autumn.

Timing

Henry's Fork - May 25 through June 30

Madison River - June 25 through July 20

South Fork - June 25 through July 20 & August 15 through September 15

Habitat

Medium to fast, oxygen rich water with rocks and boulders

Comments

Nymphs often emerge at night or during the early morning hours. Adults don't always have wings. Many males and some females of the late season species are entirely wingless or they have very small wings rendering them impossible to fly. These species complete their mating ritual on the bank and scurry across the water to lay eggs. Late in the summer trout lay in wait to target these large morsels as they scamper across the water.

Patterns (Sizes 8, 10, & 12)

Tan Rubberlegs, Golden Stone Nymph, Henry's Fork Golden Stone, Madam-X, Golden Stone Hedge Hog, Elden's Ant

Characteristics

Most species have a pale yellow to bright green body. For that reason these stoneflies are commonly referred to as Yellow Sallies. Females commonly have red egg masses on the tips of their abdomens. They commonly emerge on most rivers during mid-summer. Most of these little stoneflies become active between late afternoon and early morning hours. On some waters the dry fly fishing can be spectular when adults land on the water during egg-laying.

Timing

Henry's Fork - May 25 through June 30

Madison River - June 25 through July 20

South Fork - June 25 through July 20

Habitat

Medium to fast, oxygen rich water with rocks and boulders

Comments

Look for these small stoneflies to become active during the late afternoon and evening hours. Large swarms of females often cloud the air. The females stop flying at a height of 10 to 15 feet and glide down to the surface to lay their eggs. They can repeat the process several times. Trout can become very selective on these small, slender stoneflies.

Patterns (Sizes 12, 14, & 16)

Henry's Fork Yellow Sally, Head Light Yellow Sally, Yellow PMX

Characteristics

Three tails. Light gray wings. The body is bright yellow olive to light tan or pink. Body colors vary widely according to stream.

Timing of hatches

Early June through August. Related species can emerge well through September. Duns emerge mid-mornings and can extend throughout the day. Spinners fall in the morning and late evenings.

Habitat

Medium to fast water with gravel or rocky bottom. Very common throughout the region including all sections of the Henry's Fork, South Fork, Madison, Firehole, and other waters of Yellowstone Park.

Comments

Pale Morning Duns or PMDs provide some of the finest dry fly action of the summer. They are classified as crawler nymphs. Nymphs, emergers, cripples, duns, and spinners are very important to catch the most selective trout. Spinners vary according to sex. Male spinners have a rusty body while the body color of the females is yellow olive.

Patterns (Sizes 16, 18, & 20)

Pheasant Tail Nymph, PMD Nymph, Halfback Emerger, CDC Emerger, PMD Paracripple, PMD Thorax, PMD Parachute, Grey Yellow Nohackle

Characteristics

By far the most important group of caddis flies throughout the season. Body is usually cinnamon brown. Wings are brownish gray with small tan spots and blotches. Legs are cinnamon brown. The larvae are net makers. Pupae swim to the surface and emerge in open water. Females dive under the surface to lay eggs. When they are finished, they drift on the surface with the current. Several species are important on the Henry's Fork, Madison, South Fork, and other local waters.

Timing

June through September. Most emergence occurs in the evening, but can occur in the morning or mid-day. Egg laying can occur morning or evening.

Habitat

Medium to fast water. Larvae need clean gravel to build their nets.

Comments

The Spotted Sedge produces some of best caddis fishing. During emergence the emerging pupal imitations are effective when fished just under the surface. Spent and diving caddis patterns are effective during the egg laying flights.

Patterns (Sizes 14, 16, & 18)

Tan Electric Caddis, Tan Emergent Sparkle Pupa, Tan Partridge Pupa, Tan Spent Partridge Caddis, Tan X-Caddis, Tan E-Z Caddis

Characteristics

Three tails. Dark gray wings with bright olive green body. The body quickly darkens to dark reddish or olive brown after emergence. Duns normally emerge during the late mornings. Spinners fall early in the morning. Best activity occurs on cloudy humid days .

Timing

June into early July. The Green Drake hatch often takes place during cool spring afternoons. It can be challenging because the large flies are easy for trout to inspect in the daylight and they feed very selectively especially late in the hatch.

Habitat

Medium to fast water sections of the Henry's Fork, South Fork of the Snake, Yellowstone, and other surrounding waters. Especially common on the Last Chance section of the Henry's Fork and the tailwater section between Ashton and Saint Anthony.

Comments

Due to the wide distribution of the species, color variations exist from stream to stream. They are classified as crawler nymphs. The body color of the duns is considerably darker on the South Fork of the Snake. A related species, Timpanoga hecuba is common on the Lamar River and tributary streams including Slough Creek and Soda Butte Creek as well as the Upper Snake System near Jackson, Wyoming. The emergence period of this species occurs in late August, September, and early October.

Patterns (Sizes 10 & 12)

Green Drake Nymph, Hare's Ear Nymph, Green Drake Emerger, Green Drake Cripple, CDC Emerger, Green Paradrake, Mike's Green Drake, Green Drake Spinner, Rusty Spinner

Characteristics

Three tails. Slender body. Yellowish tan to light brown with darker markings. Wings are mottled brown, and heavily spotted.

Timing

Mid to late June immediately following the Green Drakes. Duns emerge at or just before dusk. Spinners normally fall about the same time. Some trout will often feed on nymphs or emergers, others on duns, and others on spinners.

Habitat

Very localized in the very slow sections of the Henry's Fork in Harriman Park, the Gibbon in Yellowstone Park and other waters. Needs slow water with silt bottom.

Comments

Brown drakes are very important on the slow sections of the Harriman Park downstream to Pinehaven. They are classified as burrower nymphs. Nymphs can swim rapidly prior to emergence. The focal point of the emergence moves gradually upstream a day at a time. The overall emergence period is about two weeks. Brown drakes sometimes also emerge in the morning hours.

Patterns (Sizes 10 & 12)

Brown Drake Nymph, Emerger, Cripple, Paradrake, Mike's Brown Drake, Brown Drake Partridge Spinner

Characteristics

Two tails. Dark gray wings with heavy veination. The body is olive gray with dark brown markings. Spinners are more purplish with clear wings.

Timing

June into early July. Duns emerge sporadically during mid-morning hours. Spinners fall in the late afternoon and evenings and sometimes mid-morning.

Habitat

Slow to medium fast water. The Gray Drake is an important hatch on the lower Henry's Fork below Ashton, lower Fall River, the estuaries of the Madison and South Fork of the Madison entering Hebgen Lake, and the Upper Yellowstone River below Yellowstone Lake.

Comments

The nymphs concentrate in the margins of the stream where they crawl out to emerge. They are classified as swimmer nymphs. Consequently, the duns are not nearly as significant as the spinners. The mating flights of the spinners creates superb dry fly fishing on the lower Henry's Fork. High water years provide the best Gray Drake activity.

Patterns (Sizes 10 & 12)

Feather Duster Nymph, Gray Drake Nymph, Gray Drake Spinner, Parachute Adams, Gray Wulff, Adams Parawulff

Characteristics

Three tails. Dark gray wings with medium greenish or brownish olive body.

Timing

Late June through July. Duns usually emerge in the late afternoon. Spinners fall in the morning hours. Best activity occurs on cloudy & humid days.

Habitat

Medium to fast water sections of the Henry's Fork, Madison, Yellowstone and other surrounding waters. Especially common on the Last Chance section of the Henry's Fork and the tailwater section between Ashton and Saint Anthony.

Comments

Flavs closely resemble their larger cousin, the Western Green Drake. They are classified as crawler nymphs. Hatches are sometimes sporadic and undependable. However, trout really love these robust mayflies and it doesn't take many to create a feeding frenzy. The duns emerge slowly on the surface making emergers and cripples top pattern choices.

Patterns (Sizes 14 & 16)

Pheasant Tail Nymph, Flav Cripple, CDC Emerger, Flav Thorax, Slate Olive No-hackle, BWO Parachute

Characteristics

Caddisflies are extremely important on all waters of the Henry's Fork region. Their life-cycle consists of an egg, larva, pupa and adult. Most species require a year to complete their life-cycle. The larvae are a very important food source for trout, especially during the winter months. All larvae are classifled into three types: Free roaming, net spinners, and case makers. All form a pupa prior to emergence. The pupae are normally far more important during emergence than adults. The egg-laying process either occurs on the surface or females dive under the suface to lay their eggs.

Timing

April through October. Emergence and egg laying commonly occurs during the morning or evening hours.

Habitat

All water types with various bottom structure

Comments

Other caddis hatches pale in comparison to the Spoted Sedge and the Grannom. For most anglers, defining caddisflies as to species is not as important as mayflies. Understanding the biology of caddisflies in comparison to mayflies is very important. Properly imitating the pupae, emerging adult and egg-laying adult as to color, size and shape is the key to success.

Patterns (Sizes 12 - 22)

Tan Electric Caddis, Tan Emergent Sparkle Pupa, Tan Partridge Pupa, Tan Spent Partridge Caddis, Tan X-Caddis, Tan E-Z Caddis

Characteristics

Two Tails. Slender body. Dark gray to tan upper body with pale gray to cream underbody. Wings are dark gray, usually heavily mottled in the dun. Spinner wings are often, but not always, have dark brown splotches on the leading edge.

Timing

Mid to late July through September. Duns usually emerge at dusk or after dark. Spinners fall in the mid-morning to early afternoon hours.

Habitat

Primarily lake dwellers. Callibaetis provide exception dry fly fishing on Hebgen, Cliff, Quake and other lakes in the region. They are also very common on the spring creek waters of the Harriman State Park on the Henry's Fork, Silver Creek, and other slow moving spring creeks.

Comments

Callibaetis provide some of the best dry fly fishing during mid to late summer on the Harriman Park section of Henry's Fork. They are classified as swimmer nymphs. The spinners are much more important than the duns. Their size gets noticeably smaller as the summer moves into autumn.

Patterns (Sizes 14, 16, & 18)

Callibaetis Nymph, Callibaetis Thorax, Callibaetis Cripple, Callibaetis Partridge Spinner

Characteristics

Three tails. Chalk white wings. The body of the male dun is brownish black and the female has a pale thorax with a brownish black thorax. Duns emerge early in the morning and the spinners fall shortly thereafter. Emergence is delayed with colder air temperatures later in the season. Duns sometimes emerge in the late evenings.

Timing

July through early October depending on the water. The Dun activity typically takes place in the late evening and the important spinner fall may take place anywhere from early morning until late morning depending on the weather and previous emergence density.

Habitat

Very slow to medium water with gravel or silty bottom. Common on the Harriman section of the Henry's Fork as well as the slower water on the lower Henry's Fork. Tricos are also very important on Hebgen and Quake Lake.

Comments

The duns emerge first thing in the morning or late in the evening. Sometimes the emergence is sporadic. The spinners mass in clouds prior to egg laying. The spnners usually hit the water in heavy concentrations providing some exciting but challenging dry fly activity.

Patterns (Sizes 20, 22, & 24)

Dark Hare's Ear Nymph, Sawyer's Pheasant Tail, Trico Thorax, Trico Parachute, White Black Nohackle, Trico Hen Spinner, CDC Trico Spinner, Renegade, Royal Wulff

Characteristics

Three tails. Dark gray wings with streamlined, dark mahogany bodies.

Timing

The most important emergence occurs in late August through early October. Duns emerge during mid morning while spinners fall in the later afternoon to early evening hours.

Habitat

Slow to medium fast gravel bottom water. Mahogany Duns are common on the Harriman Park stretch of the Henry's Fork, the South Fork of the Snake and several other local waters.

Comments

The Mahogany Duns provide some of the finest dry fly fishing of the late summer on the Harriman Park and other waters. They are classified as crawler nymphs. There are a number of other species that emerge throughout the summer but the late season is the best. Emergence takes place at the surface making an emerging nymph pattern very effective when trout are rising.

Patterns (Sizes 16 & 18)

Pheasant Tail Nymph, Mahogany Dun Emerger, Mahagony Dun Parachute, Mahogany Dun Thorax, Slate Tan Nohackle

Characteristics

Two tails. Light gray wings with pale olive to chartreuse body.

Timing

Late August through September. Duns emerge from mid-day through early afternoon. Spinners fall in the the evenings.

Habitat

Slow to medium moving water with aquatic vegetation. Very common on the slower sections of the Henry's Fork and other localized spring creek waters.

Comments

This mayfly was formerly classified as Pseudocloeon edmundsi. They are classified as swimmer nymphs. These tiny mayflies provide some excellent dry fly fishing on the Henry's Fork, Firehole, and other streams in the afternoon hours during September. They are multi-brood with another peak period in June through early July.

Patterns (Sizes 20, 22, & 24)

Pheasant Tail Nymph, Baetis Nymph, Halfback Emerger, BWO Thorax, BWO Parachute