South Fork of the Snake River - Hatch Chart
May Flies
| Mar | April | May | June | July | Aug | Sept | Oct | Nov - Feb |
|---|
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Nymph Type:
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Crawler |
Hook Size:
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16, 18, 20 | ![]() |
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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. 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: |
Pheasant Tail Nymph, PMD Nymph, Halfback Emerger, CDC Emerger, PMD Paracripple, PMD Thorax, PMD Parachute, Grey Yellow Nohackle. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Crawler |
Hook Size:
|
10, 12 | ![]() |
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Characteristics: |
Three tails. Dark gray wings with bright olive green body. The body quickly darkens to dark reddish or olive brown after emergence. Timing of hatches: June into early July. Duns normally emerge during the late mornings. Spinners fall early in the morning. Best activity occurs on cloudy, humid days. | ||||
Timing of hatches: |
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 St. Anthony. | ||||
Comments: |
Due to the wide distribution of the species, color variations exist from stream to stream. 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: |
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. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Crawler |
Hook Size:
|
16, 18 | ![]() |
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Characteristics: |
Three tails. Dark gray wings with streamlined, dark mahogany body. | ||||
Timing of hatches: |
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. 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: |
Pheasant Tail Nymph, Mahogany Dun Emerger, Mahagony Dun Parachute, Mahogany Dun Thorax, Slate Tan Nohackle | ||||
Hatch Chart Information Provided By: Todd Lanning
Blue Winged Olive
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Nymph Type:
|
Swimmer |
Hook Size:
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18, 20, 22 | ![]() |
Characteristics: |
Two tails. Light to medium olive/gray body with light to medium gray wings. | ||||
Timing of hatches: |
Mid-March through Early May, 12:00 PM until 3:00 PM and in the mid-summer around dusk, September through October, from 11:00 AM until 4:00 PM | ||||
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. 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: |
Pheasant Tail Nymph, Halfback Emerger, CDC Emerger, Paracripple, BWO Soft Hackle, BWO Nohackle, Sparkle Dun, Thorax, and Parachute Adams. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Clinger |
Hook Size:
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14, 16 | ![]() |
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Characteristics: |
Two tails. Dark gray wings with strong dark mottling. Body is dark olive brown to purplish black. | ||||
Timing of hatches: |
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. 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: |
Pheasant Tail Nymph, Pheasant Tail Soft Hackle, March Brown Emerger, Quill Gordon, Slate Olive Thorax, Slate Olive Nohackle. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Burrower |
Hook Size:
|
6, 8, 10 | ![]() |
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Characteristics: |
These are one of the largest of the South Fork dry flies! Wings are a light yellow. Two tails and a yellow body. | ||||
Timing of hatches: |
Hatch begins early July and sometimes last into August. These flies always emerge in the late evening. | ||||
Habitat: |
The nymphs are burrowers and need the softer muddy bottoms of the lower river. Soft current and banks with high vegitation. | ||||
Comments: |
The Hexagenia is confined to the lower river below the confluence where the Henrys Fork and South Fork Come together. Found only in the slowest parts of the river. They are a very temperamental bug and will only emerge in great numbers when conditions are perfect. This hatch will bring very large trout up to the surface to feed. | ||||
Patterns: |
Pheasant Tail Nymph, Pheasant Tail Soft Hackle, March Brown Emerger, Quill Gordon, Slate Olive Thorax, Slate Olive Nohackle. | ||||
Hatch Chart Information Provided By: Todd Lanning
Caddis Flies
| Mar | April | May | June | July | Aug | Sept | Oct | Nov - Feb |
|---|
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Nymph Type:
|
Clinger |
Hook Size:
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12, 14, 16 | ![]() |
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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 over-wintering trout. Another species produces very good fishing on the Henry's Fork, Madison, Yellowstone and other waters during late summer. | ||||
Timing of hatches: |
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: |
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. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Clinger |
Hook Size:
|
14, 16, 18 | ![]() |
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Characteristics: |
Far and away the most important group of caddisflies 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 of hatches: |
June through September. Most emergence occurs in the evening but can occur in the morning or midday. 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: |
Tan Electric Caddis, Tan Emergent Sparkle Pupa, Tan Partridge Pupa, Tan Spent Partridge Caddis, Tan X-Caddis, Tan E-Z Caddis. | ||||
Hatch Chart Information Provided By: Todd Lanning
|
Nymph Type:
|
Clinger |
Hook Size:
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10, 12, 14 | ![]() |
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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 of hatches: |
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: |
Tan Electric Caddis, Tan Emergent Sparkle Pupa, Tan Partridge Pupa, Tan Spent Partridge Caddis, Tan X-Caddis, Tan E-Z Caddis. | ||||
Hatch Chart Information Provided By: Todd Lanning
Stone Flies
| Mar | April | May | June | July | Aug | Sept | Oct | Nov - Feb |
|---|
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Nymph Type:
|
Crawler |
Hook Size:
|
4, 6 | ![]() |
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Characteristics: |
These are the largest of our South Fork insects. The adults are dark charcoal with dark orange thoraxes and underbellies. The nymphs vary from dark mahogany brown all the way 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 of hatches: |
Henry's Fork: May 20 - June 10; Madison: June 20 - July 5; South Fork: July1st July 20th. Emergence normally lasts only a few days on any given stretch of river. | ||||
Habitat: |
Medium to fast, oxygen rich water with rocks and boulders. | ||||
Comments: |
Nymphs provide nourishment to trout on a year-round basis. There are usually 2 or 3 age groups of nymphs in the water at the same time which provides several options for hungry trout. Trout can get totally gorged on the nymphs just prior to emergence. Trout often 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: |
Black or Brown Rubberlegs Nymph, Henry's Fork Salmonfly, Rouge Salmonfly, South Fork Secret, Foam Salmonfly. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Crawler |
Hook Size:
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8, 10, 12 | ![]() |
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Characteristics: |
These large stoneflies are similar in appearance to the larger Salmonfly. The Golden Stone is a couple of hook sizes smaller and are lighter in color. They are 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 of hatches: |
Henry's Fork: May 25 - June 30; Madison: June 25 - July 20; South Fork: June 25 - July 20 and August 15 - 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: |
Tan Rubberlegs, Golden Stone Nymph, Henry's Fork Golden Stone, Madam-X, Golden Stone Hedge Hog, Elden's Ant. | ||||
Hatch Chart Information Provided By: Todd Lanning
|
Nymph Type:
|
Crawler |
Hook Size:
|
12, 14, 16 | ![]() |
|
Characteristics: |
Most species have a pale yellow to bright green body. Females commonly have red egg masses on the tips of their abdomens. They commonly emerge on our river early to 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 of hatches: |
All water types. Most common on medium to fast gravel bottom stretches. This bug becomes very active about the same time the Salmon Flies hatch. July1st thru Mid August | ||||
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 - 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: |
Henry's Fork Yellow Sally, Head Light Yellow Sally, Yellow PMX. | ||||
Hatch Chart Information Provided By: Todd Lanning
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Nymph Type:
|
Crawler |
Hook Size:
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6, 8, 10 | ![]() |
|
Characteristics: |
This bug closely resembles it cousin the Golden Stone. An amber gold on it’s back with a lighter colored underside. Sometimes referred to as a Mutant Golden Stone this particular bug does not grow a full wing and cannot fly. | ||||
Timing of hatches: |
Late July through the end of August. This bug is confined to the South Fork. | ||||
Habitat: |
Cold, clean well oxygenated water. Look for the nymphs in faster riffle type water. | ||||
Comments: |
The nymphs crawl out and emerge in the dark of night and are also most active in Low light conditions. They are very successfully fished in very early mornings and overcast days. This bug is spread throughout the river system and can be found hiding under the rocks along the river bank in the heat of the day. This insect can run across the surface of the river and are often spotted in water very close to the bank. Cast your favorite pattern in very close to the bank and skitter it back toward the boat. | ||||
Patterns: |
Tan Chernobyl Ants and Eldens Ant / Barret Stonefly | ||||
Hatch Chart Information Provided By: Todd Lanning
|
Nymph Type:
|
Crawler |
Hook Size:
|
8, 10 | ![]() |
|
Characteristics: |
Smaller than Salmon Flies and Golden’s These bugs are a very dark brown on their backs and have a light green colored underside. They become very active when the water temps reach the mid 40s The males have little or no wings and do not take to the air. The females do however fly and you will often see them flying low on the water dipping their abdomen in the water laying eggs. On the south Fork it is rare to see theses bugs in great numbers like you would see Salmon Flies. Most of the time you will see then in small numbers crawling along the rocks or brush. | ||||
Timing of hatches: |
All water types. Most common on medium to fast gravel bottom stretches. | ||||
Habitat: |
Cold clean well oxygenated water. Nymphs are crawlers and prefer the faster moving water. Nymphs are found under rocks near the bank. | ||||
Comments: |
This hatch seems more confined in the Canyon Section of the river. You will find sporadically on the upper but the greatest number seem to be in the canyon. Don’t be afraid to fish the nymph patterns in off colored water. | ||||
Patterns: |
Green Machine #8 or #10, Trina’s Skwala #8 and #10, Olive PMX #8 and #10, Green Rubber Legs #8 and #10. | ||||
Hatch Chart Information Provided By: Todd Lanning
Midges
| Mar | April | May | June | July | Aug | Sept | Oct | Nov - Feb |
|---|
|
Nymph Type:
|
Swimmer |
Hook Size:
|
12 - 24 | ![]() |
|
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 of hatches: |
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: |
Griffith's Gnat, Midge Pupa, Stillborn Midge, Miracle Midge, Suspended Midge, CDC Midge Adult, Tungsten Zebra Midge. | ||||
Hatch Chart Information Provided By: Todd Lanning
Terrestrials
| Mar | April | May | June | July | Aug | Sept | Oct | Nov - Feb |
|---|
|
Nymph Type:
|
Swimmer |
Hook Size:
|
6, 8, 10 | ![]() |
|
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 of hatches: |
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: |
Griffith's Gnat, Midge Pupa, Stillborn Midge, Miracle Midge, Suspended Midge, CDC Midge Adult, Tungsten Zebra Midge. | ||||
Hatch Chart Information Provided By: Todd Lanning
|
Nymph Type:
|
Swimmer |
Hook Size:
|
12 - 24 | ![]() |
|
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 of hatches: |
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: |
Griffith's Gnat, Midge Pupa, Stillborn Midge, Miracle Midge, Suspended Midge, CDC Midge Adult, Tungsten Zebra Midge. | ||||
Hatch Chart Information Provided By: Todd Lanning
|
Nymph Type:
|
Swimmer |
Hook Size:
|
12 - 24 | ![]() |
|
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 of hatches: |
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: |
Griffith's Gnat, Midge Pupa, Stillborn Midge, Miracle Midge, Suspended Midge, CDC Midge Adult, Tungsten Zebra Midge. | ||||
Hatch Chart Information Provided By: Todd Lanning
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