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.

West Yellowstone Trout Spey Days – September 21 & 22, 2018

West Yellowstone Trout Spey Days – September 21 & 22, 2018

Welcome to the information page of the

Second Annual

West Yellowstone Trout Spey Days!

Mark your Calendars:  September 21-22, 2018.  We are thrilled to be partnering again with the Custer Gallatin National Forest and hosting our second annual Trout Spey Days event right here in West Yellowstone.  Check back in the coming months for details on event schedule, presenters, and party times!

Are you already into Spey casting and fishing for trout?  Maybe you have heard of it, but have never picked up a Spey rod, and are interested in getting involved in this super fun way to fish for trout?  This event is open to everyone, regardless of skill/experience level, age, fly shop or industry affiliation, etc.  We had a great turnout last year and have expanded the format this year to add even more opportunities for you to hang out and talk Spey with experienced pros and spend time on the water perfecting your technique.

We had a blast in 2017!

2018 Event Calendar

Friday, September 21, 5pm – 9pm – At the Shop

Big Sky Anglers Fly Shop,  39 Madison Avenue in West Yellowstone
Meet a host of experienced Spey casters,Trout Spey anglers, and instructors, and get dialed in to enjoy a whole new approach to trout fishing.  Everyone is welcome! Whether you are just beginning your journey with 2-handed rods and Spey casting, or you are a veteran with the long rod, please stop in and say hi, hang out, and talk rods, lines, casting technique, rigging, presentation, and flies used in Trout Spey and beyond.

Saturday, September 22, 10am – 5pm On the Water & 6pm – 9pm At the Shop

On Water Instruction and Demonstrations from 10am – 5pm

Madison River Bridge at Hwy 191, 3.7 miles north of the shop.  Attendees are encouraged to bring waders, snacks, water, and camp chairs, as well as their own Trout Spey gear.  No gear?  No worries, the reps will have all the goodies from the world of Trout Spey for you to try out.

Feedback from last year’s event suggested that folks had a blast and learned a lot but they also wanted more time and space on the water where they could try out gear, practice, and receive instruction outside of the formal presentations.  We listened, and this year there will be 3 main areas of the Saturday Outdoor Event.

  • Area 1 will be vendor tents. All the tents and gear from vendors will  be set up in the parking lot adjacent to the river for the duration of the event.  Attendees can meet reps, talk gear, and borrow kits for a test cast.
  • Area 2 will be an area of river set aside for folks to demo gear from vendors, get casting lessons from experienced staff and attendees, and generally free form it.
  • Area 3 is the “main stage” – a presentation area on the water. This will be the gravel bar area where the main event was held in 2017.  We will be set up for a series of formal presentations, Q&A, and lots of hands on time with Trout Spey gear.

From 10am – 11am things will build momentum, with folks arriving, meet and greets with BSA staff and reps, welcome messages, and time to hang out and drink coffee.

Following that, there will be four presentation blocks on the “Main stage”.  Each block is 1 hour in duration with a half hour in between for transition between presenters and any potential overrun, questions, and extra hands on casting and chaos from each presentation.  Stay tuned right here for more info on individual presentations.

Party at the flyshop from 6pm – 9pm 
Following conclusion of the On Water portion of the event, there will be an hour break and then we will kick off the party back at the flyshop from 6pm – 9pm.  BBQ, beverages, gear giveaways, swag, and more.

Click the Map for Directions



We are excited to have a great group of industry reps and presenters on hand this year from these great vendors.  There is no better place to try out Spey kits before you buy, or to dial in your existing Spey rod with a new line.

RODS from:

LINES from:

REELS from:


The on water portion of this event is being hosted on the public lands of Custer Gallatin National Forest.  Thanks to them, of course, for supporting this event!

Be sure to sign up for our email newsletter for updates on this event and more.

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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.

Euro Nymphing Master Class with Robert Van Rensburg – August 25, 2018

Euro Nymphing Master Class with Robert Van Rensburg – August 25, 2018

If you’ve been by the fly shop this summer you may have met Robert Van Rensburg.  Quiet and humble, Robert’s demeanor betrays his level of experience and knowledge when it comes to fly fishing in general, and Euro Nymphing in particular.  A native South African, Robert has traveled the world, fished in 17 countries, and guided in 4 countries, including in Chile with BSA co-owner Jonathan Heames.  He has also traveled as an instructor of both fly casting and fly tying.  Robert’s deep knowledge of Euro Nymphing stems in part from his background in competition angling.  He has represented South Africa at 13 World and Commonwealth Fly Fishing Championships, 11 times as the national team captain.  Robert held the seat of President of the National body of fly fishing in South Africa for 6 years, and has since been named as an Honorary life President.  Despite his background, experience, and accolades, Robert remains humble and true to the roots of fly fishing.  He loves being on the water, challenging himself to learn new things, and appreciates the beauty of an 8-inch cutthroat as much as the heft of an 8-pound brown. We are lucky to have him on the BSA staff and are thrilled to be able to share his knowledge through courses like this one.

Please read on for more info, and don’t hesitate to call the shop for more info or to get signed up for the class.

Course Information  

August 25th – 8am to 5pm  

8am-Noon Off the water instruction at Big Sky Anglers fly shop, 39 Madison Ave, West Yellowstone, MT

Noon to 1 pm – Lunch is provided

1-5 pm – On the water instruction

Cost – $150 per person, lunch is included

Euro-Nymphing specific rods/reels/lines will be provided.  A valid Montana fishing license required.  It is recommended that you bring your own waders.  Feel free to also bring any tackle that you own that is specific to Euro Nymphing.

Class size is limited to 10 students.  Spots are filling up fast.

Course Curriculum

The following topics will be covered in detail over the course of the day.

  1. Defined: The difference between Euro/Tight-line Nymphing and Indicator Nymphing.
  2. Essential gear for Euro Nymphing. Rods. Reels. Lines.
  3. Setting up tackle.  Balancing reel to rod.  Joining fly line to backing and leader.
  4. Leader formulas and lengths. When to use various leaders and leader formulas. Knots.
  5. Flies.  Importance of profile,  movement and trigger points. Size of fly, size of weighted beads.  Effects of colored beads on flies. Understanding UV and florescence in tying materials.  Understanding hook design and using the correct hooks for varying patterns and bead weights. Tying materials that give the best results . Weighting flies.
  6. Setting up tippets with multiple flies. Where to place and fish weighted flies on the leader.
  7. Tippet materials.  Diameter,  brand, fluorocarbon and nylon.
  8. Reading a river. Understanding water hydraulics.  Water temperature.  Fish species.  Time of year.
  9. Tuck cast. Tuck and reach.  Oval cast. Roll cast. Casting distance. Double haul . Use and importance of non-casting hand.  Casting for shallow and deep water.
  10. Presentation and Drifts.  Drag free drifts. Fishing 360′ degrees.  Line management.  Inducing takes.
  11. Fishing in the wind.
  12. Detecting takes and striking fish.
  13. Playing and landing fish. Landing nets.
  14. Practical session on the river with demonstrations plus one-on-one instruction.

Stillwater Presentation Q&A – Ascending/Emerging Nymphs

Stillwater Presentation Q&A – Ascending/Emerging Nymphs

I recently received this question via email from one of our readers and thought it would make a nice followup blog post.

Hi Matt,

 I just read this article on Callibaetis nymphs, and I have a question.  Don’t nymphs in stillwaters usually rise fairly straight up from the bottom?  How can I simulate that with nymph flies?  No worries on moving water, but I’m confused with this one.

Thanks so much.



Thanks for reading and reaching out!  Great question. I’d say that when they are emerging, Callibaetis nymphs will rise up at a semi-steep angle, but not completely vertically.  That said, the rising motion can definitely be a trigger to get the fish to eat.  Let me offer you 3 or 4 ways that you might accomplish this…

 1:  Floating fly line, long leader, and a weighted nymph.  Cast out and let the nymph sink down as deep as you think it needs to.  Maybe the top of the weeds if the area is shallow enough.  When you start your retrieve, the fly will naturally rise up at an angle following the leader up to the surface where the line floats.  When you’ve retrieved an amount of line about the equivalent to your leader length, stop, and let the fly sink back down again.  Repeat.  To detect takes, you need to watch the end of the floating fly line.  If it twitches, dives etc, set the hook.  You may not feel the take because the line isn’t drawing a straight line from you to the fly.  Pay attention while the fly is sinking back down too.  Sometimes that is the trigger!  It’s important that your leader not have coils in it so it is as straight a connection tot he fly as possible.  I’ve also incorporated a tiny strike indicator into this method at times, especially if there is a chop on the water that obscures my view of the tip of the flyline.  Foam pinch-ons work great for this.  Last tip, flourocarbon leaders sink faster than nylon mono leaders.

 2:  Intermediate sinking tip line (or intermediate sinking poly leader) and weighted or unweighted fly.  Basically this is the same approach as above, but with a sink tip to get the fly deeper initially.  If you are in say 10 to 15+ feet of water, the leader and weighted fly alone will be annoying or impossible to get that deep, especially if there is any wind.  Let it sink and then retrieve it up as before.  Then repeat.  Watch the color change of the line or where it enters the water for the take.  Also feel fro the grab.

 3:  Full sinking intermediate line and unweighted nymph. This line system draws the fly through the water horizontally for the most part and is my #1 way of searching for fish before, during, and after a Callibaetis hatch if I don’t see them rising in a way that allows me to effectively target them on the surface.  But, at the very end of the retrieve, when the fly is deep, and you begin stripping the last few yards of line up toward the surface, the fly does rise at an angle.  A lot of folks just pick up and cast again.  This is a mistake.  UK stillwater experts preach about “fishing the hang” at the end of a retrieve.  Focus on the last part of that rising retrieve.  Pause it, sink it, and raise it again.  Don’t strip the fly right to the rod tip, but leave a bit of line out and slowly raise the rod tip itself to make the fly ascend.  If you start getting fish only when the fly is rising, maybe you need to switch to one of the first 2 methods!

Take Care and Fish On,


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.