Big Sky Anglers Weekly Fishing Report – July 11, 2019

by | Jul 11, 2019 | 0 comments

Despite wetter and cooler than average weather fishing and hatches have finally started to really crank here in Big Sky Country.

We saw another week of Gore-Tex weather. Afternoon and evening storms have been the norm, and temps continue to run below average. Forecasts are calling for warmer weather in the upcoming week. Though, as Rob Van Kirk from the Henry’s Fork Foundation points out in his daily water supply email, “above-average temperatures have been in the forecast for weeks now and have yet to materialize for more than a few days at a time”.

Snowpack in the area has diminished in all but the highest portion of the high country. Runoff is behind us in most of the area except for the high elevation fisheries in Yellowstone Park.

We had a great 4th of July weekend complete with fireworks, parades, and salmonflies. Thanks to everyone who stopped by the shop to say Hi and chat about fishing in Big Sky Country and beyond.

There’s been a tremendous amount of interest in our Patagonia hosted trips and customized itineraries. We love sitting down with folks in the “Destination Lounge” at BSA to discuss options, and plan adventures to Argentina. Swing by sometime if you’re in town and want to chat about fishing in Argentine Patagonia.

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 Forecast

MT Streamflows

ID Streamflows

Henry’s Fork

As we roll into mid-July, and the heart of our summer season, prime dry fly fishing carries on throughout the flat water sections of the Railroad Ranch. All but a few stray Green and Brown Drakes have finished, but what remains is a consistent rotation of PMD and Flav duns and spinners along with caddis.

Warm calm mornings up in the Caldera will produce good spinner falls of Flavs and PMD’s, as well as egg laying caddis. As the day progresses into late morning and early afternoon, expect to see an emergence of PMD’s. If the skies darken late in the afternoon, which has been a daily occurrence lately, look for a good hatch of Flavs. Spinners and caddis will return in the evening and last into the darkness, provided that the storms pass and a warm calm evening ensues.

Flows in the Box Canyon have held relatively steady around 700cfs this week, and are predicted to bump up slightly as early as this weekend, by 100-150 cfs to accommodate irrigation demands in the lower watershed. This is an annual occurrence on the Henry’s Fork, but below average temps and persistent precipitation have delayed the need for increased diversion so far this season.

Fishing in the Box remains consistent with small bead head nymphs. The last of the Golden Stone activity for the watershed will still bring a few opportunistic rainbows to the surface. Some years this stonefly hatch will trickle off in the Box Canyon through July and into the beginning of August. Cool, wet weather prolongs the activity, and this could be one of those years where we see over a month of good Golden Stone fishing in the Box.

Yellowstone National Park

As we approach mid-July we will begin to see the start of the prime time season in Yellowstone Park. Things are still running a bit behind what we have seen over the last decade, but they are right on track compared to the “Good Ol’ Days” of the late-90’s.

The upper Yellowstone River, above Chittenden Bridge, opens to fishing on Monday July 15. Over the past several years we have seen this infamous fishery slowly begin to rebound after Cutthroat populations plummeted in the early 2000’s. Each year we have seen more and more fish, and last season was the first in nearly 20 years that fishable numbers of Cutts in the 12-16” range were found. We are all anxious to see what the Yellowstone River has in store for us this season. Weather and water conditions are reminiscent of the late 90’s. Hopefully the fishing will be too.

Flows below Yellowstone Lake are still running high at 4500cfs, but water clarity is good. This is a big flow for the Yellowstone River, and, although the water looks tranquil in places, it is a powerfully formidable force. Exercise extreme caution when you are wading the river for the next few weeks.

A few PMD’s and caddis have been spotted on the river around Cascade Picnic area already, and salmonflies have started at LeHardy Rapids. Green Drakes are on the horizon here. So, stay tuned for more reports from this storied fishery.

Salmonflies are crawling around the lower canyon stretches of the Yellowstone River as well. Again, flows are dangerously high here, but there is no need to wade much in these waters as most of the best fishing will be in the pockets right along the bank.

Elsewhere in the park, we are watching intently as the Northeast corner fisheries like Slough Creek, the Lamar River, and Soda Butte Creek come into shape and begin fishing well. PMD’s and caddis are present on all three of these perennial favorites, as are mosquitoes and biting flies. So, be sure to cover up as much exposed skin as possible and bring your best bug spray or lotion. A few Gray Drake spinners have been spotted on Slough Cr. Look for these big bugs (size #12) to bring picky Cutts to the surface for the next week to ten days on Slough.

The Gallatin River inside YNP is spitting and sputtering along like an old lawnmower trying to start. Water temps remain cooler than optimal here, and we really need a few warm days to jumpstart the bug activity, and the fishing. Keep an eye on the forecast, though, because this stretch of river is ready to pop with Caddis, PMD’s, Green Drakes, Golden Stones, and Salmonflies.

Madison River

July is go time on the Fifty Mile Riffle, and the river is alive with hatches these days. Warm, sunny conditions will prompt excellent Stonefly and Caddis activity. The Big Bugs have made their way up through the walk-wade waters around Raynold’s Pass and Three Dollar Bridge. Caddis activity has been breathtaking at times with monstrous swarms of adults flying amongst the streamside willows.

We’ve seen far more than our fair share of stormy weather in the Madison Valley this week, and that has squashed ambitions of evening caddis and afternoon stonefly forays. In the spirit of making lemonade out of lemons, though, stormy conditions have generated some impressive emergences of PMD, Epeorus, Flav, and Green Drake mayflies. These mayfly emergences are localized throughout the Madison Valley. Some sections of the river have good populations of specific mayflies and other do not.

Warm, calm mornings following periods of stormy weather can yield good spinner falls of the mayflies that hatched the previous day.

If the forecast finally plays out as advertised, and conditions warm up and settle down a bit, look to see the dry fly fishing become more consistent with fish looking for Caddis, Salmonflies, and Golden Stones throughout the day.

Hebgen Lake

Yet another week of unsettled weather has proven difficult for consistent action on Hebgen. The first brood of Callibaetis mayflies has been emerging for a few weeks, and the rare moments of warm, calm weather have generated some fun, although brief, sessions of gulpering.

The Chironomid and Leech game remains strong even through inclement weather. Experimenting with depth is still the key to success, especially in the arms and south side bays where weed growth has begun.

Missouri River

Joe is up on the MO this week and sent in this quick dispatch…

“I’m writing this from the river while posted up on a some sneaky fish.These ones seem to be eating spinners, which is generally the case when the hatch is light. It’s amazing how the fish get smarter the longer we sit here. A properly placed  single dry fly with a reach cast will fool them but the catch is one must do this the very first time.

Two days ago the flow went from just over 5000cfs to 5730cfs. While the fish are fat and happy, the bugs seem to be thrown off a little bit by the jump in flows. There are still bigger PMDs coming off but they are getting smaller from time to time. Yesterday in the upper river the PMD hatch didn’t really get going until almost 4pm. caddis played a big part of our day as we got most of our fish on the comparabuzz and they were hatching as soon as we splashed the boat.

We are about to pull the hook and find some fresh fish. Until next time…”

Gallatin River

In spite of all the stormy afternoons lately, the water conditions on the Gallatin are stabilizing and dropping, making for some great fishing throughout the canyon waters and upstream past Big Sky.

Salmonflies and Golden Stones are active throughout the river, and with warmer weather we should see fish looking harder for the Big Bugs.

PMD’s and Caddis are also active here and there along the Gallatin. Blind fishing size #14-16 attractors is a fun way to bring a few fish to the surface during the warmest part of the day and into the evening.