Henry’s Fork Hatch InformationWhat You’ll Learn:

●Nymph Behavior●Best Hatching Conditions●Little-Known Subspecies

● Fishing Techniques for Each Hatch

● Popular Fly Patterns

Stoneflies

What is a stonefly?

Stoneflies are fascinating aquatic insects and behave differently than caddis, midges, and mayflies. Instead of emerging in the water and trying to break the surface film, stoneflies pick holding spots very close to the river bank to begin their transformation process. These holding spots can vary; however, most stonefly nymphs appreciate water with solid flow that generates good oxygen.

Once the water reaches a certain temperature, stoneflies will crawl out of the water onto rocks, half submerged logs, and on the river bank to complete their spectacular transformation from a nymph to a stonefly adult. It is almost always a possibility of discovering a salmon fly shuck on a rock or log while fishing.

Salmon Fly (Pteronarcys Californicas)

Salmon Fly time on the Henry’s Fork section of the Snake River attracts anglers worldwide. It is often considered the west’s most legendary hatch. Just think about throwing bass poppers to aggressive, big brown trout.

Although there are several different species of salmon flies, the Henry’s Fork attracts the largest of the species, Californicas. These big bugs look like small birds flying around in the sky after taking flight.

Anglers target the salmon fly hatch by casting large foam dries very close to the bank and even bouncing there flies off of rocks. Salmon Flies start making an appearance on our waters in mid May and usually explode (depending on weather conditions) in late May on the lower Henry’s Fork.

Salmon Fly (Pteronarcys Californicas)

Nymphs

Size: Average about 1 inch

Habitat: Live in fast riffles and rocky stream beds

Hatch: Crawls to river banks and hatches outside of water

Popular Fly Patterns: Pat’s Rubber Legs Size 2 and 4 in black

Quick Tip: After spending three years in the river, salmon fly nymphs crawl to the river banks in preparation of hatching into adults. These migrations usually occur during early morning hours and at dusk. Target fish by fishing a Pat’s Rubberlegs deep in the water columns, tight to the banks at this time.

Salmon Fly (Pteronarcys Californicas)

Adults

● Size: Avg 2.5 inches long

● Habitat: Streamside vegetation, submerged logs, and large boulders.

● Popular Fly Pattern: Henry’s Fork Foam Salmon Fly Size 2 and 4 (Available at TroutHunter)

● Quick Tip: Salmon Fly hatches are notorious for being difficult to hit at the right time. When you read fishing reports, always fish above where the fishing report says there is salmon fly action. This hatch moves fast up through the river.

Check out this footage from our guide, Pat Gaffney, of the Salmon Flies on the banks of the Henry’s Fork

Golden Stone (Calineuria Californica)

Golden Stones follow the Salmon Fly hatches on the Henry’s Fork. They are easy to differentiate between their larger cousin, by their much lighter coloration and golden hue. Golden Stones are also not as large as a Salmon Fly and normally fall into a hook size between 6 and 8.

Many anglers actually prefer the Golden Stone hatch to the Salmon Fly because it is more reliable. Golden Stones stick around much longer and hatch in just as heavy abundance. Otherwise, the two different stoneflies and actually pretty similar.

Goldens and Salmon Flies hatch in the same way and also frequent the same exact areas in the stream. Expect to start seeing good hatches of Golden Stones around the first week of June.

Golden Stone (Calineuria Californicas)

Nymphs

● Size: 20-35 mm

● Habitat: Live in fast riffles and rocky stream beds

● Hatch: Crawls to river banks and hatches outside of water

● Popular Fly Patterns: Pat’s Rubberlegs Size 6 or 8 Golden/Brown

● Quick Tip: Fish stonefly nymph patterns in deeper water (minimum of 5 feet) where there is good flow and preferably a rocky stream bed. Now hold on!

Golden Stone (Calineuria Californicas)

Adult

● Size: 20-35mm

● Habitat: Streamside vegetation, submerged logs, and large boulders.

● Popular Fly Pattern: Henry’s Fork Golden Stone

● Quick Tip: Golden Stone tactics are similar to Salmon Fly tactics. Cast your dry tight to the banks and under overhanging brush/trees. A deadly tactic is to drop a size 8 Pat’s Rubber Legs about 30 inches off the back of your dry and fish both on top and in the water.

Yellow Sally Stonefly

Yellow Sallies are not taken as seriously as they should be by many anglers. These little yellow stones are actively sought for by trout. They live in rocky runs with fast flows that provide good oxygen in the water. Once Sallies reach maturity they begin to crawl to the shore and hatch on rocks, submerged logs and streamside vegetation.

After hatching, females and males mate and the females return to the water to lay their eggs by dipping their abdomen in and out. This can provide some epic yellow sally fishing, as many of the females are captured by trout or fall spent on the water’s surface.

Yellow Sally

Nymphs

● Size: 8-15mm

● Habitat: Live in fast riffles and rocky stream beds

● Hatch: Crawls to river banks and hatches outside of water

● Popular Flies: A standard hare’s ear with a gold bead size 16 will work great

● Quick Tip: Many Yellow Sallies don’t actually make it out of the water successfully to hatch. If you notice a lot of yellow sallies on the river bank, but no rising fish, take a gold bead hare’s ear and fish it tight to the bank.

Yellow Sally

Adults

● Size: 8-15mm

● Habitat: Streamside vegetation, submerged logs, boulders

● Hatch: The hatch on the Henry’s Fork usually begins in mid July and commences once September arrives

● Popular Fly Pattern: Harrop’s Fluttering Yellow Sally (Available at TroutHunter)

● Quick Tip: On windy days when you see fish up and feeding tight to the banks in riffle-like water, fish a Yellow Sally dry or a yellow stimulator using an upstream presentation and a few micro twitches of the fly.

Caddis Flies

Gary LaFontaine, very well known for his contribution to researching and writing his book, Caddisflies, once stated that he firmly believed that caddis played a more significant role than mayflies on the Henry’s Fork. Caddis fishing can be great from early May, with the start of our small black caddis, to the end of October with our larger October Caddis.

Due to the fact that there are such an abundance of caddis species, there is no need to know the individual names and hatching periods of each. It is very effective to just know what a caddis looks like and how to best mimic it with your fly selection. Two of the most important species of caddis that hatch here on the Henry’s Fork are Hydropsyche and Brachycentrus.

You need to have a good selection of different colors and sizes of caddis emergers and dries in your box.

Caddis Flies

Many caddis species begin their lives by building rock huts around their larval bodies, which if you turn some rocks around on the Henry’s Fork, you’re guaranteed to see. Inside this shelter, the caddis molts its skin and turns into a pupa.

Once the water reaches a certain temperature (different for each species) the caddis pupa climbs out of its shelter and with the help of gas bubbles, is sent to the surface film. Once on the surface film, the caddis pupa are very vulnerable to a trout. The caddis pupa emerge from their pupal shucks and fly off the water to become adults.

Females soon return to the water to deposit their egg sacks by bobbing their abdomens up and down on the water’s surface. Some female caddis will return to land to die; however, many fall spent after releasing their eggs, which can create a feeding frenzy. Check out these pictures of a caddis lifecycle

Caddis Flies

So how do you tell a caddis from a mayfly or a stonefly?

● It’s easy! Unlike mayflies, caddis wings are laid back upon their bodies. And unlike stoneflies and mayflies, caddis have a very sporadic flight pattern-- almost like moths.

What patterns should I carry?

● The emerging pupa stage of a caddis is the most vulnerable so make sure you have LaFontaines Sparkle Pupa, Harrop’s Bubbleback Caddis, and Mathews’s Iris Caddis in sizes 14-20. For the adult/egg laying stage have some EZ Caddis, X-Caddis, Harrop’s Ovipositing CDC Caddis, and Hemmingway Caddis in sizes 14-20 in black, tan, and olive.

MayfliesMayflies are some of the most beautiful creations in fly-fishing, but can sometimes be very clumsy. On the Henry’s Fork, mayflies come in a series of yummy flavors for trout throughout the fishing season.

Mayflies start off as nymphs that are either burrowers, clingers, or crawlers. Burrowers, like Brown Drakes, bury themselves in soft mud like silt. Crawlers, like Flavs, crawl upon and around rocks and eat other small nymphs. Clingers, such as Pale Morning Duns, do exactly as it sounds -- cling to the bottom of rocks.

When water temperature and barometric pressure reach agreeable terms for producing a hatch of mayflies, the nymphs fill full of air bubbles that help propel themselves to the surface film. At the surface film, the emergers try to shed their nymphal shuck, which can be thought of us a person in waist deep mud trying to escape.

Once free from their shucks, the (imago) or adult, dries it’s wing and flies off the surface of the water. At this stage, the adult molts and become a (subimago) or a spinner. Once they return to lay their eggs, they finally fall spent to the water’s surface completing their lifecycle.

Blue Winged Olives (Baetidae)

Blue Winged Olives are notorious for bringing not just individual fish feeding sporadically on the surface film, but pods of rising trout. This is due to the fact that when a hatch does occur it is very large and the BWO’s take a long time to fly off the water’s surface. A mixture of nasty weather and cool temperatures is the name of the game for this species.

Blue Winged Olives are also referred to as baetis. And there are a ton of different species of baetis. There are baetis punctiventris, baetis tricaudatus, pseudocloeon, baetis parvus, baetis vagans, you get the idea. So many just refer to them as Baetis or Blue Winged Olives. A more accurate name would be little (whatever color) quills. As there are also many BWO species that don’t fall under the genus Baetis.

Blue Winged Olives (Baetidae)

Nymphs

● Size: BWO Nymphs can range from a size 18-24 hook

● Habitat: Usually one can find BWO nymphs in any trout stream; however, they prefer cold, clean water with a high alkalinity

● Hatch: Hatches generally occur at water temperatures in the mid 40s on overcast and rainy/snowy days. On the Henry’s Fork, this occurs in April and again in September and October for big hatches.

● Popular Fly Patterns: Small Flashback Pheasant Tail, Micro Mayfly Baetis Nymph, Small Olive Hare’s Ear

● Quick Tip: The lower river is a great place to be during late fall when BWO hatches are going full force. Fish a Micro May Baetis Nymph just before the hatch occurs and watch the magic unfold.

Blue Winged Olive (Baetidae) Adults

● Size: #18 - 24 hook

● Quick Tips:

○ Blue Winged Olives take a very long time to transition from the emergent phase to the adult phase (imago). Thus emergers such as a WD-40, Harrop’s Model A Emerger and the Mayhem Floating Nymph are crucial BWO patterns to have.

○ Many BWO’s do not actually emerge and are trapped in their shucks becoming cripples. Fishing a Harrop Last Chance Cripple BWO will be great on windy days.

○ BWO spinner falls can be terrific on the Ranch in the mornings. Make sure you tie or buy some Harrop Spent Hackled Spinners in size 18-20.

● Popular Flies: WD-40, Sparkle Dun, Model A Emerger, Mayhem Floating Nymph, Last Chance Cripple, Spent Hackle Spinner

March Brown (Rhithrogena Morrisoni)

As the first important hatch of the year on the Henry’s Fork, March Browns provide great dry fly-fishing opportunities on the lower river (Ashton - Fun Farm). These mayflies on the Henry’s Fork usually begin to emerge in mid-May.

Early runoff can be a factor in March Browns emerging before planned, though. The aquatic insect prefers swift moving water over cobble. The nymphs are clingers and have flat, hydrodynamic bodies. Oddly enough, the duns will leave their nymphal shucks on the bottom of the river before emerging as full duns.

March Browns (Rhithrogena Morrisoni)

Nymphs

● Size: 12-14mm

● Habitat: Swift moving water over rocky/cobble bottoms

● Hatch: Nymphs leave their nymphal shucks on the bottom of the river before emerging to the surface

● Popular Fly Patterns: #14 Hares Ear, #14 March Brown Soft Hackle

● Quick Tip: Because March Brown’s leave their nymphal shucks on the stream bottom, a great way to fish their emergence is with a soft hackle swung slowly through promising runs.

March Browns (Rhithrogena Morrisoni)

Adults

● Size: 9-12mm

● Quick Tips:

○ Because the emerged dun swims to the surface, it’s wings are very wet and take a long time to dry. A Last Chance Cripple or a Harrop Thorax Dun can be a great way to pick up rising fish.

○ Spinner imitations are not as important as many other major mayfly hatches on the Henry’s Fork.

● Popular Fly Patterns: Harrop Last Chance Cripple, Harrop Thorax Dun, Harrop No-Hackle

Green Drake (Drunella Grandis)

The Green Drake hatch starts mid June on the lower Henry’s Fork and makes its way up river in time for the opening of the Harriman Ranch on the 15th. Quite possibly the most sought after mayfly hatch on the Henry’s Fork, the Green Drakes can make our technical Ranch fish much easier to hook on the dry.

Not only are they large (#12 hook), they’re also extremely clumsy in their attempts to become airborne once they’ve emerged. Trout will gorge themselves on Green Drakes and actively search them out while the emergence is happening.

The hatch can be better on some years than others, but if you have cloudy/rainy weather during mid June, make sure you’re out on the water! Check out this video on the Green Drake hatch on the Fork.

Green Drake (Drunella Grandis)

Nymphs:

● Size: Size 12 Hook

● Habitat: Nymphs prefer medium to fast flowing water, but choose slow moving water for their emergence

● Hatch: Nymphs begin to emerge around the second week of June with water temperatures between 55-60 degrees

● Popular Flies: #12 Olive Hare’s Ear, #12 Flashback Pheasant Tail

● Quick Tip: Green Drakes are known to float to the water’s surface to emerge, only to swim back down again. By slowly swinging your nymphs using a down and across cast, you can easily mimic this.

Green Drakes (Drunella Grandis)

Adult

● Size: #10-12 hook

● Quick Tips:

○ These meaty mayflies are super clumsy and make several attempts to go airborne. It takes them a long time to dry their wings, thus fishing a cripple or emerger pattern can prove effective.

○ Watch for rainy weather, as the barometric pressure can trigger an epic Green Drake hatch when it’s in season.

○ Spinner flight usually takes place mid-day with the fall happening throughout the day and reaching a climax in the evening.

● Popular Flies: Harrop Last Chance Cripple, Harrop Green Drake Biot Emerger, Barrett’s Spinner

Brown Drakes (Ephemera Simulans)

Usually the Brown Drakes follow the first Green Drake appearances on the Ranch waters. The nymphs are burrowers, frequenting sand, silt and light gravel areas of a stream with slow pools and runs. There has been only a couple of times in Ranch history where there has been a midday Brown Drake hatch; however, these large mayflies will most always hatch in the late evenings.

The nymphs are extremely fast emergers, almost rocketing themselves out of the water when ascending to the surface. Violent crashes on the surface can indicate trout chasing the nymphs as the emerge. The absolute best fishing during Brown Drake season is the spinner falls. This can send every single trout in the river to the surface to sip these helpless mayflies.

Sometimes the spinner falls can be a dissapointment as you might experience many trout feeding on nymphs under the surface film, but the spinners make their way into the trees never to fall spent on the water’s surface.

Brown Drake (Ephemera Simulans)

Nymphs

● Size: #8 Hook

● Habitat: Sand, silt, and fine gravel bottoms on slow pools/runs

● Hatch: Brown Drake nymphs mature in around a year (sometimes two). They are very fast emergers, propelling themselves through the water columns to the surface.

● Popular Flies: Harrop Model A Emerger, Harrop PhD Emerger

● Quick Tip: During an emergence the best way to fish the hatch is with big floating nymphs. On waters less technical than the Ranch, a good idea would be to swing these big floating nymphs down and across into promising runs. On the Ranch waters, make a down and across presentation and feed line over rising trout.

Brown Drakes (Ephemera Simulans)Adults

Size: #8 Hook

Quick Tips:

The spinner fall is what we all look forward to. It can literally bring up every single fish in the water. Sometimes the spinner fall doesn’t happen and it can be a huge disappointment as the spinners will fly up into the trees and never fall spent. The trout may still be feeding though, but not eating your spinner pattern. A Brown Drake emergence can happen at the same time as a spinner fall. A good way to tell whether the fish are eating the spinners or the emergers is rise forms. If you see spinners flying over the water’s surface and casual/relaxed rise forms -- they’re eating spinners. If there aren’t many (or any spinners present) and there are crashing/splashy rise forms -- they’re eating emergers.

Popular Flies: Harrop CDC Biot Spinner, Harrop Hackled Spinner

Flav (Drunella Flavilinea)

The flav hatch picks up right after the Green Drakes on the lower river around the town of Ashton, Idaho. A flav emergence is a favorite hatch of many of our returning clients. They start hatching on the lower river around late June and make there way up to the Ranch waters in full force by mid July.

Known as the “Little Western Green Drake,” these mayflies are literally miniature Western Green Drakes, but most of the time hatch in much greater abundance. They don’t have as much of a hard time getting off the water than their big brothers, but do provide some of the best dry-fly action of the year.

Flav (Drunella Flavilinea)

Nymphs

Size: #14 hook

Habitat: Shallow riffles with gravel/rocky bottom

Hatch: Occur at water temps between 55-57 degrees. Usually hatches in the evening, but low barometric pressure can cause early emergence.

Quick Tip: Fishing a size 14 flashback pheasant tail nymph or a two bit hooker over riffles prior to the hatch is a great way to pick up good numbers of fish.

Popular Flies: #14 Flashback Pheasant Tail Nymph, #14 Two Bit Hooker, #14 Harrop’s CDC Biot Emerger

Flav (Drunella Flavilinea)

Adults

Size: #14 hook

Quick Tips:

Spinner falls occur in the morning usually around 9-10am. The lower river can be an epic place during a Flav spinner fall. A Barrett’s Spinner pattern is a deadly fly to have during this time.

Many Flavs don’t actually emerge successfully, becoming easy prey for trout. One of the most popular flies to fish during a Flav hatch is a Harrop Last Chance Cripple.

Popular Flies: #14 Barrett’s Spinner, #14 Harrop CDC Biot Flav Emerger, #14 Harrop Last Chance Cripple

Pale Morning Dun (Ephemerella Infrequens)

Pale Morning Duns always bring consistent dry fly-fishing. Hatches start around early June below Ashton and last well into August on the Ranch. The first wave of PMD hatches are (Ephemerella Infrequens) which are between a size #14-16 hook. The second wave of PMD hatches that occurs later in the season is (Ephemerella Excrucians), which is a much smaller PMD at a size #18-20 hook.

These mayflies are so prolific that only the Baetidae species can rival them in importance on western streams. A hatch of PMD’s can be important on a certain section of water for a few weeks before moving up river and being replaced by smaller PMD species.

Pale Morning Duns create exceptional dry fly-fishing action as they float on the water’s surface for a long distance before taking flight.

Pale Morning Dun (Ephemerella Infrequens)

Nymphs

Size: #14-20 hook

Habitat: All water types, very plentiful on high alkalinity spring creeks.

Hatch: Emerges subsurface midday and into the evening.

Quick Tip: As the nymphs float to the surface to emerge, they become very vulnerable to trout in the wide open. Much like Baetis species, floating nymph patterns and emergers are great patterns for our pickier Ranch fish

Popular Flies: Harrop Model A Emerger, Harrop PhD Emerger, Film Critic, Pheasant Tail, Two Bit Hooker

Pale Morning Dun (Ephemerella Infrequens)

Adults

Size: #14-20 hook

Quick Tips:

Emergers are the absolute best way to fish a PMD hatch. These mayflies float a very long time on the water’s surface before shedding their shucks and going airborne. Although fish can be caught on duns, it’s the emergers that really stack up the numbers.

Spinner falls (Rusty Spinners) are nothing short of epic. After mating both genders fall spent to the water, which usually occurs in the early morning and again in the late evening. Rusty Spinner patterns are a must have on the Henry’s Fork.

Popular Flies: Harrop Hen Hackle Spinner, Harrop CDC Biot Rusty Spinner, Sparkle Dun, Harrop Last Chance Cripple

Callibaetis (Callibaetis Hageni)

Callibaetis are mostly known for their big hatches on many of our popular lakes around Island Park. They also hatch on the Ranch water in slow, weedy water (which isn’t very hard to find). Also known as Speckled Duns, Callibaetis feature mottled wings and a grayish-green body.

The emergence usually occurs mid-morning on the Ranch before the wind comes up. Calm, overcast days can send Callibaetis numbers skyrocketing, with hatches lasting a very long time. Callibaetis emerge in the surface film and can take a long or short time to go airborne depending on weather conditions.

Spinner falls can make for excellent fishing during any part of the day. The kiss of death for this incredible hatch is the wind, which will totally shut down any likelihood of the hatch continuing.

Callibaetis (Callibaetis Hageni)

Nymphs

Size: #16 Hook

Habitat: Slow moving water and deep pools

Hatch: Calm, overcast days during mid morning. Can come off in waves, but wind will quickly dissipate a hatch.

Quick Tip: Callibaetis hatch on the surface of the water, and will slowly make their way to the top as nymphs. Sometimes taking a callibaetis nymph (standard Hare’s Ear) and either swinging it very slowly or stripping it can entice eats. This is more popular on lakes than it is the Ranch waters.

Popular Flies: #16 Hare’s Ear, #16 Harrop Callibaetis Nymph

Callibaetis (Callibaetis Hageni)

Adults

Size: #16 Hook

Quick Tips:

The dun emergences are literally something to behold on any given trout water, but the hatches on the Henry’s Fork are prolific. In the mid-morning hours during the right hatching conditions, fish either a Sparkle Dun or a Harrop CDC Biot Emerger both in a size 16.

The spinner falls are what make this mayfly so legendary out west. The spinners bob up and down in the air like they’re on a roller coaster before finally falling spent to the water around dusk or as soon as the wind dies down. One of the absolute best patterns for a callibaetis spinner fall on the ranch is a size 16 Harrop Hackled Callibaetis Spinner.

Popular Flies: #16 Improved Sparkle Dun, #16 Harrop CDC Biot Emerger, #16 Harrop Hackled Spinner

Trico (Tricorythodes Minutus)

A solid Trico hatch is just like that of a strong baetis hatch, which can bring up tons of fish in the river. Although these mayflies are very small (size 18-24), they can come off in waves. These mayflies haven’t been popular in the fly-fishing scene until recently, due to the fact that smaller hook sizes were uncommon until the eighties.

Unlike Drakes or PMD’s, Tricos can have several different broods on the same piece of water for several weeks. They prefer high alkaline waters with cooler temperatures and do great in spring creeks. Males hatch during the late evening and night and feature dark brown/black bodies. Females hatch in the early morning and have green bodies with a dark head. As the cooler weather starts in September in Last Chance, females will hatch later in the mornings.

The hatches on the Henry’s Fork start happening in early August and can go into late September. It is truly fascinating to see a trout 20+ inches rise to your tiny, little Trico dry.

Trico (Tricorythodes Minutus)

Nymphs

Size: #18-28 hook

Habitat: Slow moving water that is untroubled from any pollution. Can be found in silt and vegetation

Hatch: Males hatch around dusk and into the night. Females hatch in the early morning.

Quick Tip: Trico nymphs are terrible swimmers and trout will feed on them as they make their way to the surface film. Nymphs are not as near as important as the duns, but a size 20 Flashback Pheasant Tail or a small, black soft hackle should do the trick.

Popular Flies: #18-24 Pheasant Tail, Any Small/Dark Soft Hackle

Trico (Tricorythodes Minutus)

Adults

Size: #18-24 hook

Quick Tips:

Probably the most important thing to get right is the hook size. Try and capture a natural and compare it to your flies. A single hook size can make or break you during a trico hatch.

Tricos will return to the water and fall spent usually within an hour after they emerge. Tricos have big wings for their tiny bodies. A Harrop Hackled Spinner is a great pattern to mimic the large wing/small body profile. The darker bodied males are the first to fall spent on the water.

Popular Flies: #18-24 Harrop Hackled Spinner, Harrop CDC Thorax Dun

Mahogany Dun (Paraleptophlebia Bicornuta)

The Mahogany Duns mark the final major mayfly hatch (besides BWO’s) on the Ranch before the snow showers hit Last Chance. The Mahogany Duns will spend their time as nymphs in faster water before migrating closer to shore to hatch in the much calmer/slower waters.

The Mahogany Duns emerge just below the surface film tight to the banks, which big fish on the Ranch usually frequent. Our big rainbows will leisurely sip the mayflies as they struggle to free themselves from their nymphal shucks.

We have clients at TroutHunter that schedule their annual trips right around the Mahogany Dun hatches, and for good reason! Mahoganies are very susceptible to trout during their emergence, as they are slow swimmers as nymphs and take a while to fully emerge and fly off the water.

Mahogany Dun (Paraleptophlebia Bicornuta)

Nymphs

Size: #16-18 hook

Habitat: Will spend their lives in faster water before moving to slower water to hatch

Hatch: Nymphs swim to the surface before hatching. Hatch in backwater eddies, riffles and flats.

Quick Tip:

Take either a Pheasant Tail or Hare’s Ear and grease it up with some fly floatant right before the hatch. If you see fish coming fully out of the water or making swirls on the surface without actually coming up, then it’s a good indication that they’re eating the nymphs.

Popular Flies: #16-18 Hare’s Ear or Pheasant Tail

Mahogany Dun (Paraleptophlebia Bicornuta)

Adults

Size: #16-18 hook

Quick Tips:

As stated before, these mayflies can take a long time to emerge, especially on colder/overcast days. Fishing an emerger pattern will usually do the trick, but have some duns on you for those overcast occasions. The dun will ride on the surface as its wings try to dry and the colder/overcast days of September don’t help.

Spinner falls can be important. Mahoganies will come back to the water after a few hours of emerging to deposit eggs. When they do fall, they fall with their wings slightly elevated and not in the usual spent position. March Browns do the same thing.

Popular Flies: #16-18 Harrop CDC Biot Emerger, Harrop Thorax Dun, Harrop Hen Hackle Spinner

Terrestrials

Terrestrials on the Henry’s Fork are very important and we usually have a good mixture of different bugs that get the fish up. Always have beetle patterns in your box, as a fish will sometimes take a beetle when it is locked into a very specific part of a hatch.

Early in the season around May we have an insect called Bibios, which are fly ants that have a mark of red in their abdomen. We’ll generally have beetles from May until September fall into the water and get eaten. Besides the abundance of fly ants in August, one of the Ranch fish favorite foods is a Honey Ant. The fish go ballistic over Honey Ants. You’ll usually see them around mid August.

Hoppers also make up a good portion of landed fish on our waters. The western winds in August will blow many hoppers into the water, so a lot of the fish are accustomed to seeing them.

Terrestrials

Must have patterns include:

#14-16 Harrop CDC Beetle, #16-18 Harrop Bibio, #16-18 Harrop Flying Ant, #16 CDC Honey Ant, #4-10 Tan/Pink/Yellow Bodied Moorish Hoopers

Stop in or give us a call at the TroutHunter Fly Shop for up-to-date information in regard to terrestrial fishing