Even if a person spent their entire life fly fishing on the waters of the Henry's Fork of the Snake River, I seriously doubt
they would be brave enough ( or a big enough liar) to contend they knew the great river well enough to be able to
consistently catch trout on it from one end to the other. It is the most diversified, cold water trout stream that exist
anywhere in the World. It's not only the wide variation in the types of water that makes up the river, it's also the
constant changing levels and flows that occur at the many different sections of water throughout its length. There's a
lot going on with the water and the environmental conditions that affect the water at any given point in time. The trout
live in a constantly changing environment that demands anglers alter their strategies for catching its brown and
rainbow trout. What Joe Blow angler did successfully yesterday, or even an hour ago, is usually worthless information.
Over a period of sixteen (16) years, Angie and I have spent many days fishing and acquiring samples of the aquatic
insects and other foods at many different locations on the Henry's Fork. I mention that not to brag about our
experience on the river at all. There are many highly regarded anglers, including a few many would refer to be legends
of our sport, that have fished the river far more than we have. I mentioned it just to make a point about one thing. If
someone could actually get a PhD on fly fishing the Henry's Fork, even with my experience, I would probably only be
rated a C student in my Junior year. I am confident that no one would have received a Rhodes Scholarship on fishing it,
and if they did, there wouldn't be anyone at Oxford qualified to teach it. Don't worry about that though. You can get
educated on it. The river isn't going anywhere.. If you are familiar with our series of instructional fly fishing DVD
programs, you are aware that we use the slogan "You Can Get Your PhD in Fly Fishing Right Here". Let me explain
One morning, after fishing the Henry's Fork of the Snake at the famous Railroad Ranch the previous day, I stopped by
to pick up some flies from one of the oldest fly shops in the nation - Bud Lilly's Trout Shop, located in West
Yellowstone, Montana. The shop owner, Dick Greene, asked me how things were going. I told him while we were putting
on our waders the previous morning in the parking lot at the Old Railroad Ranch section of the Henry's Fork, two guys
pulled up next to us with a very interesting outlook on fishing Yellowstone Country. I explained that I asked them the
standard "how's the fishing" question and they replied that it was great on the Madison River. They continued to
explain that they had been catching large numbers of big rainbow trout below Hebgen Lake for the past three days.
They had been fishing the salmonfly hatch that was currently taking place on the Madison. I continued to explain that
they even commented that the Madison River salmonfly hatch was the best and most productive hatch they had seen
in their last twenty years of fishing the entire Yellowstone area. Mr. Greene knew we were aware of that, because he
knew we had recently been fishing the Madison. I'm sure he was wondering why Angie and I, as well as the two
gentlemen I was referring to, abandoned the great fishing taking place on the Madison to fish the Snake River. I
explained that we were trying to learn new water but that they had a completely different reason. When I asked them
why they abandoned the Madison for the Snake, they explained that they had rather catch one rainbow trout on the
Henry's Fork than twenty on the Madison River. As soon as I finished telling the story to Dick, with a serious expression,
on his face he said, "You need a PhD in trout fishing to catch trout on the Henry's Fork".
Dick continued to explain that he felt sure that it was the challenge of catching the large rainbows on the Henry's Fork
that the guys preferred to catching trout at other places where it wasn't so difficult to do so. He was correct. That's
exactly what the two gentlemen pointed out. It didn't take us but one day to learn that catching the big rainbows in the
Harrison State Park section of the Henry's Fork (the previously called Railroad Ranch section of the river) isn't easy.
When we met the two gentlemen, we were about to fish that section of the river for our second day in a row. That next
morning, we were headed back for the third attempt. I just wanted Dick's opinion and advice about it. At the time, I had
made my living from teaching people to fish for the twenty years prior to that; however, at the same time, I had
managed to only catch a total of three trout in two days of fishing- one the first day, and two the second day. What
made it even worse, was that I had managed to see at least thirty or more, large rainbow trout feeding on the surface of
the water in plain sight.
Our entire reason for being there was to make instructional DVD on fly fishing for trout. I had been doing that
successfully for the previous twenty years. I had host and produced forty-six (46) instructional videos on saltwater
fishing. At the time, more of those video programs had been sold on saltwater fishing than any others in the World.
They still sell and even today, have still outsold them all. Thanks to the royalties I was receiving from the fishing and
boating programs for my previous twenty year of work, we were able to continue to travel and fish for about 200 to 250
day per year producing new videos on fly fishing.
I learned years before this story took place, to never give up on catching fish. I wasn't about to let pea brain size fish
outsmart me on the Henry's Fork. I knew I had to not only figure out exactly what they were feeding on at any given
time. I knew I had to fool them into taking a fake fly for it in crystal clear, smooth flowing water with nothing to hide
behind. I was headed back to a river I had managed to catch three trout on in two days of fishing for one reason. I knew
I had to learn to meet the challenge of consistently being able to catch several of the big trout in a day of fishing tough
to fish water, or choose another profession. I also knew Hell would freeze over before that would happen.
What I didn't know at the time, was the long term consequences of Dick Greene's explanation. That night in our motel
room, I wrote the slogan "You can get your PhD of trout fishing right here" in our daily fishing journal as well as on our
video logs for that day of fishing. We have used the phrase ever since because the most important thing you need to
catch trout on the Henry's Fork is knowledge - knowledge about the food the trout rely on to survive, and how to go
about imitating it to the point you can fool the trout into taking a fake imitation of that food. .
After all, those guys were exactly right. It's the "challenge" that makes fishing the great sport it is. I knew that
very well. I had fished for the World's hardest to catch fish, the blue marlin, many, many days, all over the Western
Hemisphere. I spent many days over several years, studying the seas and skies, and altering the lures riding the waves
of the offshore blue waters, just to experience the "thrill of a lifetime". Although, I have seen many caught, I have only
caught seven as an angler; however, it doesn't take but a very few minutes for one to count higher than the number of
people that have caught that many as an angler.
If you spend the day and catch a few eighteen inch, wild rainbows from the smooth flowing, clear waters of the Harrimon
State Park section of the Henry's Fork, you have done something even a self proclaimed experts would be hesitant to
lie about. There would be something else unique about doing it. A knowledgeable angler that has fished that section of
the river very much, would never insult you by insinuating your were lucky. They would know better than that. If you
want to rely on pure luck fishing there, you would probably catch just as many if you fished in your backyard swimming
pool. Now there is more to this story. There are many times and places in others sections of the same river that with a
little luck, a first year fly fisher might catch ten to twenty, fifteen to twenty inch trout in a day of fishing. There are times
and places in some of the fast water sections of river where the big rainbow and brown trout will eat about anything
remotely resembling a big stonefly.
A description of the Henry's Fork Section of the great river:
Keep in mind, the Henry's Fork is only one part of the Snake River. The Snake is a 1078 mile long river that's a
tributary of the mighty Columbia River. Another section of the Snake begins in Yellowstone National Park and
eventually enters the Henry's Fork as the South Fork of the Snake River.
The Henry's Fork consist of all three types of trout waters. It is tailwaters, or water below dams. It's also a spring river.
Much of its water comes from underground along the river banks and from spring creek tributaries. A great amount of
its water would be classified as freestone stream water. In places, it is all three of the above combined into one. In
places, it is difficult to tell how it should be classified. That written, there's one way you can classify it that few
knowledgeable anglers would question. You could classify it as a great trout stream.
The Henry's Fork of the Snake River starts at Big Springs. My favorite tactic is to fish from the observation bridge with
live bait. I have caught a lot of trout doing.........I'm kidding, of course. I've only dreamed of casting there, and I wouldn't
use live bait if it was allowed. You can look at some large trout, eye ball to eye ball but fishing isn't permitted at that
location. The water is so clear and the fish so visible, you probably wouldn't have much of a chance of catching one,
even if you used live bait. Big Springs is an uppermost major source of water for the Henry's Fork and a very, very
important one because it is spring water. To explain that in a short and simple manner, let's just say the water
chemistry, especially its high pH, supports a huge diversification and population of aquatic insects, crustaceans and
other food for the trout. The large amount of food results in the trout growing fast and to very large sizes.
Just below the outlet from Big Springs, the Henry's Fork receives water from Henry's Lake through Henry's Lake Outlet,
a relatively small stream. Have you heard of Henry's Lake? To describe it, let me just say that books have been written
about its huge trout and its great still water, trout fishing opportunities. By the way, in addition to Henry's Lake, there
are also a few creeks entering the river in that area that add even more water to the outlet.
Now, you would think from what I have written so far, that Henry's Lake, and especially, Big Springs, furnishes the water
for the Henry's Fork. It does to a large extent; however, it is only the starting point of this great river. There's another
major lake, many other springs and several rivers made up of different types of water, that make up the Henry's Fork of
the Snake River. The many diverse sources of water is the strong foundation that makes it one of the World's best
Island Park Reservoir:
About nine miles below Big Springs, nearby Mack's Inn, the river flows south to where it enters Island Park Reservoir.
By the way, Island Park Reservoir, also has its fair share of large trout. The river is changed big time at this point
because it in essence becomes a lake. Below the Island Park Reservoir, the river depends on the water that flows
through the dam or its tailwater. Technically, I guess you could say everything below Island Park Reservoir is a tailwaer,
but the only problem with that is that it has many other small to very large tributaries entering the river from that point
downstream that aren't tailwaters. There are several more spring creeks as well as more freestone streams that add to
The Henry's Fork River doesn't get very far below Island Park Reservoir before the Buffalo River adds another dose of
spring water. It comes from springs located within the Caldera. The river gets bigger along its way from its beginning
from the water of many other springs and small tributaries. The Buffalo River flows into the Henry's Fork just below
Island Park Dam. By the way, it has a good population of brook trout as well as rainbows.
The Henry's Fork Box Canyon:
Just below the Buffalo River's confluence, the Henry's Fork goes into a huge transition referred to as the "Box Canyon".
If I blindfolded someone that had never been there, they would think they were fishing a freestone stream with some of
the best pocket water they had ever fished. The Box Canyon is a very popular, three mile long section of the river that
has a population of huge rainbow trout. During the spring runoff and during the mid-summer, irrigation water demands
keep the Box Canyon current strong and fast. Wading is dangerous during those periods of time. The only way to fish it
during those times is by drift boat and even then, I would want a well experienced guy handling the oars. At other times,
when the water is not swift and dangerous, it is feasible to wade the waters of the box canyon. Fishing can be great at
times, but much of the time, you will probably need to use nymphs or streamers to be successful. Trout can be taken
on dry flies during several hatches that occur there, but most often you will do better fishing flies below the surface.
Harriman State Park:
So far, I have just touched on the upper part of the Henry's Fork, from its beginning downstream through the Box
Canyon. The Henry's Fork flows out of the Box Canyon near Last Chance, Idaho. There it flows into a very moderate
sloping, to almost flat volcano caldera. The river's water changes big time, going from fast, flowing, pocket water, to
spring creek-like, smooth flowing water. It flows into and through the Harriman State Park that I featured in the above
introduction. Many of the old timers, including myself, still call it the Railroad Ranch section of the river. The park is an
11,000 acre wildlife refuge that's holds approximately seven miles of the Henry's Fork of the Snake River.
Many avid fly anglers think the waters of the Harriman State Park section of Henry's Fork, is the finest trout water in the
World. Others don't like that section of the river and many refuse to fish it. There's a simply reason why some dislike it.
Catching its large rainbow trout isn't easy. It presents a substantial challenge to the best anglers. Judging how well a
trout stream should be rated is usually highly dependant on how anglers view the difficulty of catching trout. Some
anglers like the catching part of their fishing fast and easy, and others enjoy a challenge. The reason it is a challenge
to fish, is the trout are all wild, stream-bred fish that live in very clear, smooth flowing, spring creek-like water with lots of
conflicting currents. Consistently catching them demands precise presentations of very good imitations of the aquatic
insects they feed on. By the way, many of our Perfect Fly patterns were developed from samples of the insects
acquired from the waters of the Henry's Fork. During the past six years since the beginning of Perfect Fly, many
anglers have discovered their effectiveness on the Henry's Fork. This is especially true when they have been used on
the glass, smooth waters of the Harriman State park section of the river.
There is one thing certain about the State Park section of the river. It offers dry fly fishing at its very best. I'll again
stress that this section of the river is not easy to fish, not even for the anglers that have fished it regularly for years. It
offers a challenge to anyone, a challenge I think is appropriate for any angler that contends they are good at the sport
of fly fishing for trout. You don't have to be concerned as to whether on not the big trout are there. There are plenty of
them. All you have to be concerned with is fooling them into taking your fly for food. I'll put it this way. When you do
catch a few trout from the Harriman Park section of this great river, you have done something to be proud of. If nothing
else, it provides a lot of self-satisfaction, knowing you conquered a good challenge. If it were not for modern day email,
Facebook, Twitter, digital cameras, etc., I would say catching trout from this section of the Henry's Fork is something
worth writing home about.
Harriman State Park to Riverside Campground:
Below the Ranch section, the river again changes character. It turns into faster flowing, water with long riffles and runs.
The water is this section is completely different from everything upstream. Fishing in this area is similar to fishing in the
box canyon area but with a more moderate declination, less plunges, waterfall, and less rough water. This section
includes approximately six or seven miles of the river downstream from the end of the Ranch section to the Riverside
Below the campground, the river flows into yet another canyon. This one is called Cardiac Canyon. You can probably
guess why. I have fished this section several times without having a heart attack, so it just means it can give the old
heart a good workout getting in and out of the canyon. Some people consider it to be the best water the river has to
offer. One reason is that is the fact that it's not nearly as heavily fished as the Box Canyon, or the Ranch section.
Another reason is that the access to this part isn't all that great. It is a deep canyon. Part of it can be floated in a drift
boat. You can get to the stream on foot in a few places. Hatchery Ford is one easy to get to areas. Even if you have
your own boat, I would suggest that you shouldn't fish this section without first doing so with someone experienced in
floating the canyon. You cannot float downstream of the Hatchery Ford area. By the way, don't get the idea from the
name "Hatchery Ford" that this river is stocked. It certainly isn't. That would be a huge insult to the Henry's Fork.
You have to get to the river below Hatchery Ford by hiking in. It consist of fast, rough, pocket water. There are also
some waterfalls downstream, including Upper and Lower Mesa Falls. Fishing is great between the falls as well as below
and above the falls. You just have to get there on foot. This is a very deep canyon section, but it is well worth the effort
it takes to fish it, especially if you are there during a good hatch. I have been told it has some huge trout although my
personal experience hasn't proved they are any larger than they are in the Ranch section. The canyon ends at the
confluence of the Warm River.
Below Lower Mesa Falls in Cardiac Canyon, the Henry's Fork of the Snake River goes into a wider area of canyon and
flows to the reservoir above Aston Dam. The Warm River adds its water to the Henry's Fork just below the Cardiac
Canyon. It's a twenty-five mile long river that flows along the east side of the Henry's Fork from near the Island Park
area not a long way from the upper Henry's Fork. It flows south for most of its length but turns west, and runs into the
Henry's Fork. The Warm River is a spring-fed stream, but it looks more like a freestone stream in its lower section. It
also has some very good fly fishing opportunities.
Warm River to Aston Reservoir:
From the Warm River confluence to the Aston Reservoir, the stream consist of typical pocket water, with long runs,
riffles and pools. It also adds some more brown trout to the rainbow population. We have only fished this section of the
river a few times, and always during the hot summer months when the only thing hatching were some caddisflies and a
few Pale Morning Duns. It's not that those insects do not offer good fishing opportunities, it is just my understanding
that the best fishing in this area of the river occurs during the salmonfly hatch in late May and early June. We have not
fished this section at that particular time, nor have we been there in the fall months, which is also reported as being a
good time to fish this section of the stream.
We have not fished the Aston Reservoir, but I have been told by reliable sources that it holds some nice size trout and
that fishing its still waters can provide some good opportunities at certain times of the year. Since we haven't fished it,
that is about the extent of my knowledge. I'm mentioning it because of its position in the Snake River system and it's
effect on the fishing below the Ashton Dam. You should be beginning to see why it would take a lifetime to know this
entire system of water very well.
Aston Dam Tailwater:
Below Aston Dam, the Henry's Fork of the Snake River is yet an even different type of river than it has been since it's
beginning. We have spent a lot of time fishing this tailwater section of the river below Aston Dam. Next to the Harriman
State Park section, we think this is one of the better sections of the river. This part of the Henry's Fork has some very
big trout and with the exception of the summer months, it provides great fishing. During the summer months of July,
August and September, a lot of water is diverted from the river for irrigation needs. It still provides good fishing, but
nymphs become more important, and dry fly fishing less important. Don't get this wrong. Even during the summer, this
section of the river can provide better fishing than many other well known western trout streams.
Angie and I have spent a lot of time in this section in the early season, meaning May and June. We have been told by
the locals that the great fishing starts well before that, but we have not experienced it. The river is fed by lots of small
springs which helps by keeping the water a little warmer than it would otherwise be in the early season.
There are several areas this section can be accessed from. We normally fish the river below the bridge from the road
that heads West from the little town of Aston. There are other access areas that are just as good. During the early
season, especially during the month of June, you will see a lot of drift boats on this section of the river. One reason is
the action is well ahead of most of the other fly fishing opportunities in the Yellowstone area. During the salmonfly
hatch that starts near the end of May and runs through June, this is a very popular area.
Chester Dam Tailwater:
There's yet another section of the Henry's Fork below the Chester Dam that provides good fishing. This tailwater flows
downstream of St. Anthony, to where the river combines with the South Fork of the Snake to form the huge Snake
River. These stretches of the river have some huge trout. There are more browns and some that grow very large. Like
the Aston Dam tailwater, it flows through lower elevations that the upper sections of the river and offers anglers fly
fishing opportunities when many areas in this part of the west are still flowing through deep snow.
Henry's Fork Aquatic Insects and Other Trout Foods:
The type of food for the trout on the Henry's Fork of the Snake varies greatly depending on the section of the river you
are dealing with. Elevation changes, changes in water chemistry, and the effects of water flows due to irrigation needs
are all factors that affect the hatches. Another big factor is that much of the water lies below dams. The still water in the
lakes changes the water chemistry and the type of aquatic insects that live in the river below it. The water chemistry in
the lower sections of the river are affected by the chemicals and fertilizers used for farming along the river and its
tributary streams. Another factor affecting the type and population of aquatic insects is the different types of water
flows. Parts of the river are like a smooth flowing spring creek and parts of it consist of fast, pocket water similar to a
freestone stream in flow, but not in water chemistry.
In general, all of the water is low in acidity. Most of the water in the river comes from springs. The pH is relatively high,
although it varies from one section of the river to another. In general, the river is very fertile and has a huge population
of aquatic insect life. Of course, that is a big factor in why its trout grow so large.
The first aquatic insect that you should consider important at Henry's Fork of the Snake River, as well as most
anywhere else in the country, are the many species of mayflies anglers call Blue-winged Olives. Most anglers don't
want to think in terms of small flies when they are visiting the West to fish for trout. They want to think in terms of big
flies and big hatches. While there's nothing wrong with that, it's just a fact that little BWOs are just as important on the
Henry's Fork as they are anywhere else in the nation. Just about anytime from March through the month of November,
there's a hatch of some species of little mayfly called a Blue-winged Olive going on somewhere on the river. Generally
speaking, there's an early season and a late season hatch of the baetis species of BWOs. Some of the other species
called BWOs are also bi-brooded.
Many anglers don't think about fishing the Henry's Fork until mid June, when the season starts in the Harriman State
Park section. Those anglers miss a ton of fly fishing action, including the big Salmonflies. These huge stoneflies start
hatching on the lower part of the river and move upstream. They are plentiful in the fast water, or pocket water sections
of the river, such as the canyons. They are followed closely by the Golden Stoneflies and the Little Yellow stoneflies
most anglers call Yellow Sallies..
It is impossible to detail all the aquatic insect hatches that take place on the Henry's Fork in a article such as this. The
river has just about every species of aquatic insect that exist in the western United States, and the hatch times vary
greatly from one section of the river to another.
Lower Henry's Fork River Hatches:
Since much of the water in the river comes from springs, the water in the lower Henry's Fork is not as cold as one may
think in the early season. The BWOs start hatching around the first of March and can last through April. Between Aston
and Chester, the salmonfly hatch will begin just past mid May.The guides are usually very busy on this section of the
river at that time. The fishing can be fantastic.
Several species of caddisflies start hatching during the month of April, and continue throughout the rest of the season
until November. The Little Black Caddis (Mother's day hatch) usually starts around mid March to the first of April, and
last three or four weeks. By mid May, the Spotted Sedges start hatching. These are the most prolific species of
caddisflies to hatch. It will last until the first week or two in July, with different species hatching at different times. At that
time of the season, the river flows are greatly affected by irrigation demands. Shorty after the Spotted Sedges start
hatching, usually near the first of June, the smaller Little Sister Caddis species will begin to hatch.
In June, the large Western Green Drakes will start to hatch in this section of the river. It will last at the most, a couple of
weeks in the lower river. Nearer the end of the month of June, the smaller Flavs, or Small Western Green Drakes, will
begin to hatch.
Other than the BWOs, the most important species of mayfly on the lower river are the Pale Morning Duns, or PMDs.
They hatch over a very long period of time beginning in late May. Although it name implies it hatches in the morning,
the little pale-yellow mayfly can hatch just about anytime of the day depending on the weather and water. They can
hatch in large numbers and trigger a feeding frenzy.
There's another important mayfly found in the lower section that starts to hatch around the first of June - the Gray
Drake. These larger mayflies hatch in the late afternoons. The nymphs and the spinners are the most important stages
of life to imitate.
Although the PMDs and a few species of caddisfies will hatch in this section of the river throughout the summer months,
the irrigation demands on the water creates a less than ideal fly fishing situation. By the end of September, the action
will again pick up in this section. October, can be a great month to fish with the Blue-winged Olives being the main
species to imitate.
Harriman State Park Section Hatches:
The hatches at the Harriman State Park section of the river are similar to those I just mentioned for the sections of the
river located below Aston Dam. The hatch times are different. The Harriman State Park section is a spring river with
smooth flowing water, and is quite different than the tailwater below Aston Dam. Most of the time, the water
temperatures are different, for one reason, it's at a higher elevation. Another reason is because it's not located directly
below a dam. It does lie below Island Park dam, but not directly below it, and that makes a difference. There's the Box
Canyon, an entirely different type of water section between them. The fast moving pocket water has different hatches
and hatch times.
There are probably as many different species of aquatic insects in the Harriman State Park section of the Henry's Fork
as there are anywhere in the Western United States. It comes close to having about every aquatic insect that exist in
the West. That written, there is one insect that resides there that dominates the minds of most anglers when thinking
about the river - the Western Green Drake. The Green Drake hatch is very good for the Island Park economy, for sure.
In recent years, there have been many stories and jokes told about the Green Drakes of the Henry's Fork. One of my
favorites is that when the hatch starts, the locals will say "the Green Drakes are hatching and the fish are feeding
great", then pause, and add, "on caddisflies". There's some truth to that statement. There are a lot more caddisflies in
the park section than Green Drake mayflies. Another thing, is that like many other aquatic insect hatches, the Green
Drake hatch varies in length and intensity from year to year, depending on the weather. Like many other mayflies,
about a week or ten days is as long as the big drakes are going to hatch in any large numbers in any one section of
the river. If you only have a few days to fish, and a select time frame to do it, being there at the right time isn't always
We were usually in the Yellowstone area for at least a month, and the longer than normal time frame allowed us to
catch the hatch, but for those who have a short time frame than cannot be adjusted with a day or two notice, it often
makes catching the hatch purely a hit or miss thing. I should also point out that we haven't always taken the Green
Drakes up on that offer, even when we have been in the area. For one reason, the Henry's Fork has its largest crowds
during the time normally advertised for the Green Drake hatch. It usually occurs near the end of the month of June, but
can vary, depending on the weather pattern. Keep in mind, the fishing season in that section of the river doesn't open
until June 15th, due to nesting waterfowl.
The bottom line to this, is that it isn't necessary to catch the Green Drake hatch to catch trout. It's fine if you do, but
certainly not necessary. The fish feed every day, not just one week of the year, and they feed on many other aquatic
insects as well as many other types of food. I could have stated this an entirely different and more accurate way. I could
have just implied "the Green Drake hatch is over rated".If you happen to catch it, fine, but if you don't, you should be
able to catch just as many trout on the many other hatches that take place on the river.
Pale morning duns and baetis species of Blue-winged Olives will most likely greet you on opening day. We show the big
Green Drakes starting on June 15th, but most likely nearer the end of the month for this section. The Lesser Green
Drakes, or Flavs as most anglers call them, hatch during July. These are also called Small Western Green Drakes. You
will also find some large Brown Drakes that hatch near the same time of the month. They may not start until around the
first of July.
About the middle of July, you will usually find the Callibeatis (Speckled Wing Quills) mayflies hatching. Those are
basically still-water mayflies, but they hatch in some sections of the State Park area. This hatch can last through the
month of August. Yellow Quills, Ginger Quills, Dark Red Quills, Gray Drakes, and Tricos are a few of the many more
mayflies that exist there.
We have done just as well in July and August on terrestrial patterns - ants, beetles and hoppers, as we have mayfly
imitations. You can walk the banks and fish these flies,and not have to be as precise with your presentations. It still
requires plenty of skill to be consistently successful, but it is less demanding than fishing the areas away from the
banks where there isn't any cover at all.
You will find caddisflies hatching the entire season. They are mostly the Spotted Sedges, Little Sisters but there are
dozens of other species such as Little Short-horned Sedges, White Millers, Black Dancers, Green Sedges, October
Caddis and others.
Canyon Section Hatches:
The Box Canyon and Cardiac Canyon should be the same as the other sections of the river as far as the most of the
species of insects are concerned, but the hatch times will vary slightly. Hatches in the Cardiac Canyon take place just
prior to those in the box canyon because it is at a lower elevation.
The Salmonfly hatch usually occurs near the end of May, and ends around the first or second week of June. The egg
laying part of this hatch will be one of the few times dry flies will work well in the canyons. Just as important, in my
opinion, is the Golden Stonefly hatch. It starts before the larger Salmonflies hatch ends, and continues a couple of
weeks or longer after it has ended. Before the Golden Stonefly hatch ends, the Yellow Sallies (Little Yellow Stoneflies)
will begin to hatch. One thing about the canyons that is different is, you can expect to find plenty of stoneflies for a long
period of time from near the end of May through July.
The trout in the Box and Cardiac Canyons grow very large. They feed on leeches and Sculpin in addition to aquatic
insects. That means that streamers work well just about anytime. The summer irrigation demands affect the water flow
through the canyon. The best time to fish it is between the end of the runoff near mid-June until the middle of July. The
irrigation demands usually end around the end of August and the canyon becomes less turbulent again. In other
words, the fishing in the canyon is more controlled by the water flow than the hatches. As mentioned above, it is
fishable during high water, but to be safe, it should be done from a drift boat. Wading is very dangerous during high
water periods and should be done with caution anytime in the canyon.
In addition to the stoneflies, most all of the mayflies and caddisflies found in the other sections of the Henry's Fork are
there except for the slow water species such as the Speckled Wing Quill mayflies and the long-horn caddisflies.
Smooth Water Fishing Techniques:
I can't possibly go into all the methods of fishing the different types of water in the Henry's Fork River in this article.
That would take far more than I have time to devote to what is already, a very long, detailed article about this great
river. I would like to cover on technique that is necessary to fish the smooth, clear water sections of the river, that the
majority of anglers are not familiar with. The Henry's Fork of the Snake River is full of aquatic insects of many different
types. Eighteen inch trout are common. It is almost impossible to consistently catch the large trout in the Harriman Park
section without using this type of downstream presentation, so I think it is worthwhile to point out a few things about it.
The thing that separates this river from most any other trout stream that has large trout is the fact these huge trout will
commonly eat insects on the surface of the water. If you were blindfolded and set loose in this section of the river, you
would think you were fishing a large spring creek. In fact, that's how many anglers refer to it, and rightly so. Its
vegetation that is typical of most spring creeks, creates complex currents that are not easy to fish. In order to be
successful, instead of blind casting a large expanse of water and hoping a rainbow will take your fly, anglers need to
locate and fish to individual trout. Locating them is the easy part. Fooling them into taking your fake fly presents a big
The Harriman State park is the section of the river that Angie and I have probably spent the most time on. If most of
your fly-fishing experience consist of fishing the fast, pocket water of freestone streams, you're most likely going to
have a very difficult time catching trout in this section of the river. If you have mostly fished for stocked trout in any type
of water, you are going to have a difficult time catching trout from this section of the river. If you have been fishing this
section of the river for the last fifty years, you may still have a difficult time catching them consistently. It has often been
described as being similar to fishing a flooded parking lot. That reference is made in terms of it being able to easily to
wade the river. The bottom is fairly level and the stream is usually relatively easy to wade, even in the middle of the
Some Things that make the Ranch Section Difficult:
Like most spring creek water, this section is full of aquatic vegetation. To say the least, the vegetation makes the
smooth currents very tricky. Getting a drag free drift is usually a big problem. The best way to catch the big rainbows in
this section is to find a trout feeding on the surface and fish specifically to catch it. Random casting achieves very poor
results. You will probably spook a hundred trout for each one you catch. To be blunt, you will have a difficult time
catching one trout if you cast all day using every fly in your box.
Finding a trout that is feeding on the surface isn't always possible. Most of the time, the trout are feeding on the
surface a hatch is underway. In fact, much of the time during the day, hatches are usually not taking place. When an
insect hatches, it occurs at a specific time of the day depending on the particular species of aquatic insect. About the
only other time surface feeding occurs is during the late Summer and early Fall when trout are feeding on terrestrial
insects that blow or otherwise get in the water.
Another problem that's common on the Henry's Fork is multiple hatches. It is common to find more than one hatch
taking place. Sometimes, there may be several. This presents the problem of trying to determine which insect the trout
are feeding on.
There's yet another problem that's fairly common - multiple anglers. Often, when the highly famed, prolific hatches are
taking place on the Henry's Fork, there are lots of anglers. That's a new phrase I just created for a lot of guys wading
the river spooking trout that haven't the slightest idea about what they should be doing. The Henry's Fork isn't exactly a
secrete fly-fishing destination.
Let me add even more problems for you to consider. The trout in the State Park section are usually very selective.
There's so much aquatic insect life available to them, they can be very selective and eat all they want to eat of any one
insect. You may find trout along the banks eating one kind of insect, and trout scattered throughout the wide river
focusing on other specific insects. There's never a shortage of food. That's why the trout grow fast and big in this great
river. This doesn't mean they will reject one insect for another. It does mean that they will be in a location or feeding
lane where a particular insect is hatching. It is possible, but rather unlikely, that two different insects are hatching in the
same feeding lane at the same time. In that case, the trout may eat a fly imitating either insect.
Solutions to the Difficulty:
For the last few paragraphs, about the only thing I have done is point out some of the many problems you face when
fishing the park section of the river. To keep from scaring you away, let me describe some specific methods of fishing
this section of the river that I and many others have used successfully. When you consider all the negatives, keep in
mind the single biggest thing that makes fly fishing for trout so great on the park section of the Henry's Fork is there's
isn't a better place anywhere in the United States to catch large trout feeding on the surface on dry flies.
Spring Creeks and Spring Rivers allow you to see trout feeding on the surface. At some time during the day, on most
any day, you most likely will be able to find them feeding on the surface. Instead of casting your fly in water with a
broken surface and hoping a trout is there, you can hunt and find them in this section of the Henry's Fork. When a
trout is feeding on the surface, it is focused on watching a very small space in a single drift line. The trout cannot see
objects at a distance. Their window of vision is very small. This helps an angler approaching the trout get fairly close to
the trout (within twenty or thirty feet) if they do so without disturbing gravel and rocks on the bottom when wading or
stumbling around on the bank.
Slow movements is also a big key. Trout are not nearly as apt to spot someone moving very slowly in their peripheral
vision as they are someone that's moving fast or making sudden movements. The first objective is to get as close to
the trout as possible without spooking it. The second objective is you want your first cast to drift down the trout's
feeding lane in time with the rise. In case I lost you, let me explain.
Usually, trout that are feeding on hatching insects on the surface come up from their holding positions, feed on the
surface two, three or four times, and then return to their holding position. You have to time your cast so that the fly is in
the feeding lane when the trout rises again to eat. The best way to do this is watch the trout rise to the surface and eat
a few times. Don't rush things. Unless you spook the trout, it most likely isn't going anywhere. Try to establish a rhythm
to the frequency the trout is rising to the surface. Ideally, you want to time your presentation such that your fly drifts
over the exact area the trout is feeding on the surface in time with it rising to the surface to eat. That sounds rather
easy, but the problem is doing it right the first time without letting the trout see your movements, or detecting your fly
line or leader. If you allow fly line to drift over the trout, it or even its shadow pass over the trout, you will usually spook
the fish. The fly has to pass within a few inches of the rising trout such that it sees the fly before it sees anything else,
or otherwise you will put the fish down. If your timing is off, or if the exact drift line of your fly if off, you must be able to
pick the fly line up off of the water to make another presentation without the trout seeing it. The fly should drift a slightly
different line (to the left or right) of the leader and fly line.
Another problem is it's often difficult to get a drag free drift in the feeding lane. This is especially true If the current is
swirling upstream of the fish. In most cases, that is exactly what's taking place. These conflicting currents are caused
by the underwater aquatic vegetation. I can't possible detail everything you need to know and do to get a drag-free drift
in conflicting currents in this article. I'm just pointing out that you must be able to do it to be successful and fooling the
trout, but here are some key points for you to consider.
Your first cast is the most important. That's why you want to get as close to the fish as possible. You want to avoid
making any false cast over the fish. Each time you fail to get the fly drifting drag-free, in the feeding lane at the time the
trout rises to eat without hooking it, you lower your chances of catching it. In some cases, provided you don't spook the
trout too badly, it will continue to eat and just ignore your fly. That's when you begin to wonder whether or not your fly is
matching what the trout is feeding on. Often, anglers change flies when this happens, yet still gets the same results. In
this case, most of the time, it was most likely the presentation that turned the trout off. It requires doing more than one
thing right. It requires a good presentation and it requires selecting a fly that does a good job of matching the
appearance and behavior of the insect the trout is feeding on.
Most of the time, I use a downstream approach and presentation. Sometimes, you may spot a trout feeding in a
location where it isn't suitable to make a downstream approach or presentation. You may spot a trout feeding that's just
upstream of the position your wading. In some cases, repositioning yourself will most likely spook the trout. When your
wading, looking for trout, a fish can also rise immediately to your left or right, and you would need to make a
presentation without repositioning yourself and taking a chance on spooking the trout. In other words, you need to
know how to make good drag-free presentations in all directions relative to the current.
If done correctly, a downstream approach gives you the advantage of the trout seeing the fly first, before
the trout can see the leader or fly line. Slightly down and across presentations are usually better than direct
downstream presentations. If you cast directly downstream, and the trout doesn't take the fly, your leader will pass
directly over the fish. If you don't recast soon, the line will pass over the fish. If you recast too soon, you may spook the
trout picking the line up off the water. If you cast slightly down and across, you can let the fly pass over the fish, and if it
doesn't take the fly, allow it to get well below (downstream) of the trout before recasting.
The very first time I fished the State Park section of Henry's Fork, I fished in an upstream direction. I spooked every
trout that I saw feeding. I soon began to make very long cast. When I started making long cast, I began to spook them
with my line and leader landing too close to the trout, or when picking up the line to cast again when it was drifting too
close to the fish. I made a number of other errors. It's just a fact that when you start making long cast, say from thirty to
sixty feet, your accuracy decreases. In order to catch trout consistently on the smooth flowing, spring creek sections of
the Snake River, you must make very accurately cast.
Yep, you must make very accurate cast; you must stay hidden from the trout even though there is no where to hide;
you must use a fly that looks and acts very much like the real insect the trout is feeding on; that means you must know
what it is feeding on, you must set the hook on a light 5X or 6X tippet without breaking off; and if your lucky, you must
land the rainbow trout after it has just about emptied your fly reel of line. There is nothing to it.
The easiest way to go about it is to get a PhD in fly fishing.
The Henry's Fork of the Snake River
Copyright 2015 James Marsh
April, 2015 Issue
have no idea why I selected the Henry's Fork of the Snake River to feature in this issue. Being behind schedule
on about everything I am doing these days, I felt compelled to write about fly fishing a trout stream that is
probably the most difficult one I could possibly select. Just knowing where to start and end is a huge problem.
Great Fly Fishing Destinations
I know they are not easy to see in
this photo, but you are looking at
thousands of wild, rainbow trout
up to 20 inches in length. If we
could zoom in, you could see them
sticking their noses out of the
water, sipping in insects drifting
on the surface.