Hatch Profile – Spruce Moth

Hatch Profile – Spruce Moth

One of the most overlooked and misunderstood terrestrials in Yellowstone Country fly fishing is the Spruce Moth. Commonly known as the Western Spruce Budworm Moth (Choristoneura occidentalis Freeman) these native insects are naturally occurring and found throughout the Rocky Mountain West from southern Canada to Arizona.

From late July through August you can see these size 12-14 moths tumbling across the water in fisheries that are lined by coniferous forests. Trout love feeding on Spruce Moths, and this activity produces excellent dry fly fishing at a time when most of the summertime hatches have finished for the season.

Adult moths are about 1⁄2-inch (13 mm) long, with a wingspan of approximately 1 inch (22-28 mm). Both sexes are similar in appearance, although females may be slightly larger. The wings are variable in color, ranging from gray to orange-brown; they also may be banded or streaked, and some individuals may have a conspicuous white dot on the wing margin.

Spruce Moths are endemic parasites that feed on the new growth of Douglas Fir, Subalpine Fir, and Engelmann Spruce trees. Adult moths hatch from their pupal cases in late July or early August. After emerging the adults are viable for 7 to 10 days in which time they mate, deposit eggs, and die.

Females deposit their eggs in orderly rows on the underside of conifer needles. Larvae hatch from these eggs in as little as 10 days, and seek shelter in the bark and lichen on tree trunks and limbs. Here the larvae spin a silken structure known as a Hibernicula, and remain inactive through the winter.

In spring (May-June) the larvae venture out from their hibernicula to feed and continue maturing. Spruce moth larvae will feed on newly sprouting foliage sometimes spinning webs of silk to encapsulate multiple buds, shoots, or cones.

It takes 30-40 days of feeding for a larvae to become fully grown at which time they pupate within the webs of silk they had formed previously to feed.

Western Spruce Budworm Moth infestations are cyclical and their abundance is regulated primarily by predation and environmental conditions. Spruce Moth larvae have many natural predators including spiders, beetles, wasps, chipmunks, squirrels, and a host of birds.

Freezing temperatures also play a key role in regulating populations. Though, it’s not the -30 and -40 degree arctic blasts of winter that kill Spruce Moth larvae.  They spend the winter tucked away in their warm, dry hiberniculas. Rather, it’s freezing temps in May and June, after the larvae have emerged and are on the feed, that prove fatal.

Abundances of spruce moths vary from year to year, but even on years with mild infestations this is an important terrestrial to imitate if you are fishing in August on waters like the Madison, Gallatin, Yellowstone, Lamar, Hebgen, or Henry’s Fork, just to name a few. They can also be an important insect to be prepared for on many of our regional stillwaters.

Big Sky Anglers Weekly Fishing Report – 08/09/2018

Big Sky Anglers Weekly Fishing Report – 08/09/2018

The “Dog Days of Summer” are officially here. It’s been hot, dry, and a bit smoky across Yellowstone Country lately. Fortunately though, we’ve seen good moisture by way of afternoon thunderstorms, and some downright chilly mornings with temps in the 30’s. This, coupled with the benefits of last winter’s solid snow pack and a wet spring, is keeping water conditions in great shape throughout the area.

It’s still dry fly season in Yellowstone Country, but August is the month to bring your “A-Game”. The trophy trout that call this region home have seen it all by this point in the season, and they are in no mood for a bad drift or clumsy approach. Success depends upon stealth, accuracy, and finesse. If you’re coming to the area to fish, be sure to get in some casting practice before your trip. If you’re already here, and having trouble, swing by the shop, and spend some time with one of our expert instructors or book a guide trip to fine tune that cast.

Our two local wildfires are behaving themselves somewhat compared to the blazes in other parts of the West. The Grassy Ridge Fire, which was located approx 15 miles north of Saint Anthony, ID is 100% contained and officials have deemed it no longer active. The Bacon Rind Fire located approx 23 miles north of West Yellowstone has grown slightly to 488 acres and continues to burn slowly through mixed old growth and beetle-killed forests.

Weather forecasts look hot and dry for the next week with highs pushing 90 this weekend. A slight cool down is in store for next week, though as temps get back to the upper 70’s and low 80’s. Nighttime lows look to stay in the cool 40’s which is great for water temps.

Read on to see our take on this week’s fishing, and check out the links below to stay current on area forecasts and flows.  Stay tuned as we report each week on hatches, flows, weather, and more. For the most up to date info stop by the shop, give us a call, or drop us a line.

West Yellowstone Weather Forecast


Yellowstone National Park

The high country is the place to be when it gets hot and dry. Temps never get as warm up in the Park as they do in the lower river valleys, and many of the waters are just now reaching their average flow levels after a long snow melt.

The northeast corner of the Park has seen some muddy water as the result of strong thunderstorms this week. Flows are currently back to normal, and the forecast looks dry for the foreseeable future. But, it’s always a good idea to check the flows before making the trek to fish the Lamar River or Soda Butte Creek. Expect to see caddis, pmd’s, flying ants, spruce moths, and hoppers here.

The upper Yellowstone River (from Chittenden Bridge to Yellowstone Lake) continues to produce some remarkable cutthroat trout. Both Green and Gray Drakes can still be found in isolated sections along with Caddis, PMD’s, Epeorus, Flavs, and Callibaetis. Flows are finally approaching a manageable level at roughly 2700 cfs. However, it’s still a formidable river, and crossing comfortably is not yet an option.

This is an ideal weekend to explore a small backcountry stream in the park. If you spend your winter gazing at topo maps like we do, you surely have a hit list of little blue squiggly lines to check off. Now’s the time.

Madison River

For a couple of weeks now we’ve been talking about fishing the Madison with spinners and Caddis during the mornings and evenings in order to find the most productive dry fly fishing. Well, now two of our favorite terrestrials are on the scene, and the fish have something to feed on through the afternoon hours too. Both Spruce Moths and Flying Ants have been active throughout the Madison valley. Spruce Moths can be found anywhere coniferous trees line the river. These size 14, tan-colored moths get blown into the river from stream side trees, and the trout waste no time capitalizing on their misfortune. You can see flying ants in columns of winged adults towering above sagebrush flats in the float stretch. Size 14-16 red and black flying ant patterns are a must have this time of year on the Madison. Trout tend to feed better on Ants when the sun is out, and a well-presented fly with the most terminal of dead drifts is essential.

Don’t forget about those Epeorus spinners and egg-laying, Hydropsyche Caddis in the mornings and evenings. They are still around in mass, and we should see another week or two of good fishing with them before it starts to stall out.

Gallatin River

There may not be a better river to fish with Spruce Moths in our area than the Gallatin. From just downstream of the park boundary to the mouth of the canyon near Gallatin Gateway, the stream bank is packed with coniferous trees that produce a constant supply of moths. Outside of Salmonflies and Golden Stones, Spruce Moths produce the best dry fly fishing of the season here. This is a great time to find studly browns in shallow water looking for a dry fly to eat.

Hebgen Lake

The Grayling Arm, the Madison Arm, and the bays on the south side are all seeing some good gulper fishing now. Callibaetis, Tricos, and Midges will bring fish to the surface on calm mornings. Impressive numbers of Tricos can be seen hatching in the evenings. After emerging, they molt on any surface available leaving their telltale, white sub-imago skin behind as a calling card. Fish don’t seem to pay much attention to them in the evenings, but when they gather the next morning to mate in clouds of millions it’s a different story. Lately, fish have been on midges early, transitioning to tricos by mid-morning, and finishing with Callibaetis by late-morning if the wind holds off. It’s go time for Gulpers on Hebgen. If you find yourself out on the lake, and you’re not seeing rising fish, or the fish that are rising aren’t tracking well, try another spot. Some days are hot in one area and not in another. It’s a big lake with a ton of great gulper spots.

Henry’s Fork

If you have been too busy the last couple of months to come fish the Railroad Ranch section of the Henry’s Fork don’t feel bad. We get it. Life gets in the way sometimes. It’s not your fault that your long lost cousin decided to get married in June, or that your annual Civil War reenactment group just had to get together to commemorate the anniversary of Gettysburg in July. But now it’s August, and it’s time to get serious about fishing the Ranch. Some of our favorite hatches happen in August. There are still good numbers of Flav spinners in the mornings, Callibaetis and Tricos are going in their select areas, and, the springs have some PMD’s. Honey Ants are mandatory now as are hoppers. There may be no better time, and no better place to get your ass kicked by a world-class rainbow trout than right now on the Ranch.

Elsewhere on the system, the Box has been a great bet for consistent nymph fishing. Though, with warm weather be prepared for an increased emergence of inflatable unicorns and otherwise befuddled floaters.

Big Sky Anglers Weekly Fishing Report – 08/02/2018

Big Sky Anglers Weekly Fishing Report – 08/02/2018

August is upon us, and just like that it’s gotten hot and smoky here in Yellowstone Country.  Runoff is well behind us and we are transitioning into mid-summer conditions on our local fisheries. There’s a bunch of great fishing going on throughout the area, but it’s time to start thinking strategically about where, when, and how we are fishing these days.

Two local blazes, as well as numerous regional wildfires are adding smoke to our skies. Locally, we have the Bacon Rind Fire burning just west of Yellowstone Park roughly 23 miles north of West Yellowstone, and the Grassy Ridge Fire burning 15 miles northwest of St. Anthony, Idaho.  The Grassy Ridge Fire is responsible for most of the lower level smoke around West Yellowstone these days. Currently it is 97% contained at just under 100,000 acres. Minimal fire activity is expected over the next few days, and it is likely that we will see a slight break in the smoke as crews mop up this blaze. The Bacon Rind Fire has grown to 414 acres, and continues to burn slowly through beetle killed timber on ridge lines above the Gallatin River.

We’ve seen some scattered thunderstorms and showers across the area this week. The upcoming forecast looks seasonal with high temps in the low 80’s and low’s in the 40’s. Again, there is no substantial moisture predicted for the foreseeable future.

Read on to see our take on this week’s fishing, and check out the links below to stay current on area forecasts and flows.  Stay tuned as we report each week on hatches, flows, weather, and more. For the most up to date info stop by the shop, give us a call, or drop us a line.

West Yellowstone Weather Forecast


Yellowstone National Park

August is one of our favorite times in Yellowstone Park, because we begin to shift our focus to the many backcountry fishing options here. More than 90% of the 4 million plus annual visitors to the park never leave the roads or boardwalks, and see only 10% of its 2.2 million acres. That leaves thousands of miles of fishable water in the park’s backcountry to explore with drastically fewer people than frontcountry fisheries.

This is a great time of year to hike into headwater streams, and backcountry lakes. Bring some bear spray, a map, some good boots, and your spirit of adventure. There’s nowhere else in the lower 48 states that provides more backcountry wilderness fishing opportunities than Yellowstone Park.

If your adventures include a trip to the northeast corner of the park be sure to keep an eye on the forecast and streamflows. Afternoon thunderstorms can temporarily blow out some of these fisheries, and make for a long fruitless backcountry trip.

As always, give us a call anytime at the shop (406-646-7801) for updates on conditions, and recent fishing reports. Additionally, If you are in the area, and thinking about a backcountry trip, swing into the shop. We can spread out the maps, and help you sort through the dozens of available options.

Madison River

As we move into August our focus changes from the famous bugs of our early-season hatch cycle to some lesser-known, but arguably more important mid-season insects like Epeorus Mayflies, Flying Ants, Spruce Moths, and Nocturnal Stones.

When it gets hot and dry in the Madison Valley it’s important to plan your day around the cooler air and water temps found early in the am and later in the pm. Epeorus mayflies will emerge sporadically throughout the day this time of year, but adults will concentrate in mating flights and spinner falls in the mornings, and especially in the evenings. These size 16, pale-cinnamon colored spinners will bring good fish to the surface, but keep in mind that trophy fish on the Madison have seen more than their fair share of attention already this season, and they are not in the mood for bad drifts. Perfect presentations will prompt some beautiful fish to rise to your fly. Sloppy presentations with drag will leave you wondering if there are any fish living in the river at all.

As you fish your way through the Madison Valley these days you will undoubtedly see some empty stonefly shucks on streamside rocks and logs. These are not leftovers from earlier Salmonfly and Goldenstone hatches. Most of these shucks are from a later season stonefly that we refer to as a Nocturnal Stone. These are flightless stones that skitter across the water’s surface after emerging in the nighttime or early morning hours. We rarely see these size 8 and 10 Stoneflies during the daytime hours, but if you’re diligent you can find one along the bank. When you do, you’ll have a hard time hanging on to the little guy as all they want to do is run away, and they’re good at it. As such, when fishing size 8 and 10 dry stonefly imitations, like Chubby Chernobyl’s, you will often see an eat after mending the fly and imparting a “twitch” into your drift.

Another less than obvious insect that is massively important to trout in the Madison River, and across Yellowstone Country, this time of year is the flying ant. Stay tuned to the Big Sky Anglers Blog and Newsletter for an in depth profile on these terrestrials later this season. In the meantime, be sure to have some size 14-16 red and black ant imitations when you’re fishing. On many days this is one of the few dries that will bring larger fish to the surface during the afternoon hours.

The last of these overlooked insects that is important on local waters now is the Spruce Moth. This terrestrial moth is found in area forests, and in places where forests border the river, you can find size 12-14 tan moths fluttering along the water. Whenever these moths show up fish are on the lookout, and are willing to take a well-presented imitation throughout the day.

Hebgen Lake

It’s August now, and that means it’s officially Gulper Season on Hebgen Lake. Some days the fish and bugs know that…some days they don’t. Either way it’s worth paying attention to this fantastic fishery on calm mornings. From now until the frost comes in September you can expect to see Callibaetis and Trico mayflies on Hebgen. When the conditions are warm and calm, especially for several days in a row, you can find groups of large Hebgen trout feeding consistently on the surface.

When it’s going, this is some of the most exciting sight fishing with a dry fly anywhere in the world. Be prepared to make long, accurate casts to a moving target, and keep your expectations on numbers of fish low. This is a quality vs quantity game. On exceptional mornings, we are tickled to get a mere handful of fish on a dry fly.

If the dry fly game isn’t your thing you can also still target these trout subsurface with Callibaetis nymph or chironomid imitations fished blind or sight cast to feeding fish.

Henry’s Fork

Just when we had all but written off the PMD hatch this year on the Railroad Ranch section of the Henry’s Fork the river decided to remind us that in the end it in fact has the final say in hatches. It seems as though the river was saving all of its PMD’s for mid-summer this year. We’ve finally seen some strong emergences of PMD’s in the Ranch and good numbers of quality fish looking for them. That’s not to say it’s been easy fishing by any stretch of the imagination, but there’s been opportunities. In addition to both PMD duns and spinners, there have also been some Flav spinners, and a few Gray Drake spinners.

The Box Canyon remains one of the most consistent options in the area. Nymphing has been good with the usual assortment of small beadheads fished deep, and Golden Stones continue to provide fun dry fly fishing.

Big Sky Anglers Weekly Fishing Report – 07/26/2018

Big Sky Anglers Weekly Fishing Report – 07/26/2018

It’s hard to believe that this is our final report for July. We thought June flew by, but July has just evaporated!  We’re half way through our summer season, and Yellowstone Country continues to produce some great fishing. Flows in much of the area are still a bit above average, and the high country remains green; a sure sign of the great moisture year we’re having.  

Despite all the moisture, the start of the wildfire season is upon us. Our first local wild fire, the Bacon Rind Fire, is burning in the Lee Metcalf Wilderness 2 miles West of HWY 191 and the Gallatin River. The fire started as the result of a lightning strike on July 16. Smoke can be seen rising from the ridge lines above the Gallatin in the park stretch around mile marker 24. The fire is just over 200 acres, and is fulfilling its natural role cleaning up old, beetle-killed timber.

Afternoon thunderstorms have been frequent this past week, and there looks to be more in the forecast. Seasonal temps with highs in the 80’s and lows in the 40’s are predicted for the foreseeable future.

Read on to see our take on this week’s fishing, and check out the links below to stay current on area forecasts and flows.  Stay tuned as we report each week on hatches, flows, weather, and more. For the most up to date info stop by the shop, give us a call, or drop us a line.

West Yellowstone Weather Forecast


Yellowstone National Park

Yellowstone River – There is a whole generation of Yellowstone anglers that never new the Yellowstone River in the Park back when it was in its prime. Since the mid-2000’s populations of Cutthroat Trout have been virtually non-existent in this legendary fishery. For years we told stories about the wonderful fishing that “used to be” in classic spots like Buffalo Ford (now named Nez Perce Ford), Cascade Picnic area, or below Le Hardy Rapids. Well, we’re finally starting to see some of the fantastic fishing from those stories of the “good old days” again. Numbers of fish in all size classes have been seen feeding on good hatches like Salmonflies, Golden Stones, PMD’s, Cadddis, and Drakes.

The canyon stretches of the Yellowstone River, which have continued to fish well through the years, are fishing well again this year. Flows are still dropping, and more of the river is becoming accessible every day. Golden Stones, and the rare Salmonfly are still flying here, and good fishing can be found if you’re willing to put in some effort to hike into this steep, rugged terrain.

Lamar River – Afternoon thunderstorms have been all around the area this week,  but amazingly, they have missed the Northeast corner of the park. Keep an eye on the forecast if you’re planning on heading over to the Northeast corner of the park as these storms are common this time of year, and can quickly blow out the river. A quick glance at the flows can tell you if the river is blown. Any quick spike in flows on the graph is usually accompanied by some dirty water. As soon as the spike comes down, the clarity should be improved.

Fishing has been good on this gem from late morning through the evening with attractor dry flies, as well as imitations of PMD’s, Caddis, and Drakes.

Gallatin – The park stretch of the Gallatin is a great place to escape the heat of the day on these hot afternoons. PMD’s, Caddis, and Little Yellow Stones are keeping fish interested in the surface. The biting flies are still around but not quite as obnoxious as they have been in recent weeks. Smokey conditions may exist in the stretch between the highway bridge around mile marker 24 and Specimen Creek.

Madison River

Flows on the “Fifty Mile Riffle” have been flatlined at 1330cfs below Hebgen for the past week. That’s nearly 400 cfs higher than the average flow for this time of year. Higher flows have helped to mitigate the effects of afternoon air temps in the upper 80’s in the Madison Valley, but the best dry fly fishing continues to be in the early morning and late evenings with Epeorus spinners and Caddis. Nocturnal Stones have been active in float stretch, and the first few flights of Ants have been seen throughout the valley.

Hebgen Lake

Lake levels are still close to full pond on Hebgen. That means those fish have a lot of space to occupy, and the weeds are still a long way from the surface in many spots. The Callibaetis and Trico mayflies that drive our coveted Gulper Fishing are starting in earnest, and we’re beginning to see some consistently tracking fish. The next six weeks will be the best of the season on Hebgen for Gulpering.

Henry’s Fork

Fishing the famed waters of the Railroad Ranch at Last Chance lately has been a bit like watching your favorite baseball team, the one you’ve routed for since you were a kid, during a season when they’re in last place with a .284 average (Sorry Baltimore Fans!). There’s been some moments to stand up and cheer, and some moments to throw your bag of peanuts and boo. It’s not all bad when your team stinks, though. It’s usually pretty easy to get a seat at the game, and when the rare home run ball sails over the fence it’s memorable and rewarding. Like loyal fans we continue to go to the games with un-ending optimism that today will be the day that the team comes together and pulls off a “W”. It’s halfway through the season. The All Star break is behind us and it’s time for the club to make a run for the postseason. Some of our most exciting games are just around the corner. Tricos, Callibaetis, Ants, Hoppers,   Mahoganies are still to come on the schedule. So, keep the faith, loyal fans, and keep going to those games. You never know when stars will align and give you that perfect game, or that walk-off homer.

The Box Canyon has fished well all season, and it continues to be one of the highlights of this fishery. You can still find a few Golden Stones around, and the nymph fishing with small bead head midge and mayfly imitations has been great.

The stretch from Warm River to Ashton is another consistent option for some dry fly fishing with PMD’s and Caddis, as well as consistent nymph fishing.

Hatch Profile – Hydropsyche Caddis

Hatch Profile – Hydropsyche Caddis

Caddis are commanding members of the aquatic insect community on all of the trout waters in and around Yellowstone Country. From April through October, there isn’t a day that goes by without some sort of Caddis activity. Of the dozen or more different types of Caddis that produce good fishing in Yellowstone Country, the genus Hydropsyche is the most important. From May through August, Hydropsyche Caddis consistently produce more quality fishing situations than all of the other Caddis combined.

There are four unique species of Hydropsyche found in Yellowstone Country, and luckily there’s no direct benefit to differentiating between them for the fly angler. All four species have tan bodies, wings that range from tan to speckled brown, and vary in size from 14 to 16.

Next to Pale Morning Dun mayflies, there is not a more ubiquitous insect in Yellowstone Country trout waters than the Hydropsyche Caddis. If you are fishing moving water anywhere in our region you can find Hydropsyche in the larvae, pupa, or adult stage.

Hydropsyche larvae are net spinners who build unsophisticated shelters out of silk that double as a food catching structure. In his groundbreaking work Caddisflies, Gary LaFontaine reports observing Hydropsyche larvae using a silk anchor line to hang in the current as a method of migration from rock to rock. LaFontaine even went so far as to experiment with white-colored tippet to imitate this anchor line.

When Hydropsyche larvae begin metamorphosis and start the transformation to pupa they seal their rudimentary case with silk and remain entrenched for 2 to 3 weeks. The adult Caddis slowly grows within the pupal cuticle until it reaches maturity. Once mature, the insect chews its way out of the sealed case and begins it’s emergence.

Emerging Caddis pupae are, most simply, a fully formed adult draped in a thin pupal cuticle filled with gas bubbles. Hydropsyche pupae ride the current near the bottom for some time before rising through the water column. Once they reach the surface, pupae battle their way through the meniscus, and struggle to free themselves from the pupal shuck. This is an epic struggle that can take several minutes, and often times it’s unsuccessful. Large numbers of crippled and stillborn pupae can be found during emergences.

The best emergences of Hydropsyche Caddis occur from mid-June to mid-August in Yellowstone Country. All of our major fisheries have robust populations of Hydropsyche, and fishing the evening emergence and morning egg-laying flights are ingrained in the rich angling history here.

Adult Hydropsyche Caddis spend 2 -3 days resting after emergence before they begin to form mating swarms. Mating flights generally occur well above the water, or around streamside vegetation. It’s not uncommon to see dense clouds of Caddis surrounding riparian willows as the sun gets low in the Western sky and the heat of the day subsides. These massive mating flights generally provide nothing more than a distraction to anglers as the insects seldom touch the water.

Egg-laying females, on the other hand, can be very important. Female Hydropsyche return to the water after mating, and dive to the bottom to lay their eggs. After releasing their eggs, the females drift in the current and slowly ascend back to the surface. There, the egg-layers fight once again to break through the meniscus and make an apparent re-emergence. Spent, egg-laying females then helplessly ride the surface currents. From the time egg-laying Hydropsyche re-enter the water to the time they re-emerge, opportunities abound for trout to prey on them. Egg-laying activity peaks in the morning and evening hours, though females can be seen sporadically throughout the day.