by | Jun 16, 2021 | 0 comments

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The bright orb in the sky has been looming over southwest Montana, eastern Idaho and Yellowstone National Park for what seems like an eternity. Clouds have been few and far between this past week and we saw some record high temps across the tri-state area. Things finally cooled down the past two days and it wasn’t quite as toasty as it had been. The wind is still blowing, rest assured. There is a chance of rain over the weekend on Sunday and some more mid week, keep those fingers crossed! The Madison and Henry’s Fork flows have bumped up and while the rivers are still a bit low, there is more water flowing over the rocks; most likely we will see another bump in flows here soon. Overall, fishing has been pretty darn good.

Big Sky Anglers is OPEN from 7am to 9pm seven days a week. Our fly shop remains a clean and healthy environment for both our customers and staff members. Stop on by, say hello, and we’ll get you taken care of. Most importantly, stay safe, stay healthy, and enjoy your time outside.

Take care and fish on,
~ Joe, Justin, Jonathan, and the BSA Crew



Island Park Dam:  800cfs

Ashton Dam:  1630cfs

St. Anthony:  1090cfs

Falls River at Chester: 676cfs

Life adrift or along the banks of the Henry’s Fork has been good this last week and it looks like we’ll have some more of that to come this coming week.  The river is now open from top to bottom, with the opener on the Railroad Ranch section in Harriman State Park coming into its summer season this last Tuesday, June 15th.  Fishing options abound but keeping an eye on rapidly changing conditions and adapting will reward those wishing to ply the Fork’s waters for trout on the fly.

The Box Canyon is now a lot less bumpy than it’s been for the past month, running at a cool 800 cfs, the trout will be comfortable with lots of room to hide and the angler is happy with lots of inviting structure to work on and around.  Rubberlegs 6-10 , pheasant tail nymphs 14-16, red zebra midges 14-16, perdigon flies like the bullet quill or BSA’s own Robert Van Rensburg’s Tubby Morten are doing the trick out there.  Remember, the Box is a great place to work on your short line nymphing skills!  Too much line out there leads to poor drifts and less success!

The Railroad Ranch had a buggy opening with reports of good hatches of pmds, some green drakes, and caddis all around.  This week holds promise of being a great opening week, but imminent demand for irrigation flows might lead to rising water out of Island Park Dam, keeping an eye on flows is a good idea.  Stability leads to good hatches at current flows, but variations in flows can upset insect activity and trout behavior.  On the menu for this week are: pmd patterns in all stages (emerger, cripple, dun, and spinner), caddis patterns in tan and olive 14-18, green drakes (always good to have several different patterns on hand in both emergent and adult stages).  

The canyon country remains fishy and fishing well, flows are still ideal for dry/dropper rigs and there are still some golden stones flying about.  We like the Chubby Chernobyl/Rubberlegs nymph combo in here to get things started, but if the action is slow, change the color of the Chubby and try a fast sinking mayfly nymph like a tungsten beaded pheasant tail in a 12 or 14, or your favorite perdigon pattern.
Warm River to Ashton Reservoir has been fishing well with good action on small nymphs and dry/dropper rigs.  Keep an eye on flows as large increases can increase turbidity down here and make for a slower morning than usual.  

Below Ashton Reservoir the river has had some great green drake fishing, complemented by good hatches of pmds, caddis and flavs.  Golden stoneflies are still around as well as smaller stones like yellow sallies and western olives.  Green drakes are likely to come to a halt with the hot sunny weather we’ve been experiencing and in the immediate forecast.  Be on the lookout for flav and pmd spinner falls in the mornings and evenings, sparse but good caddis activity, flav hatches in the afternoon, and make sure you add some gray drakes to your fly selections down here, as they should be around the corner.  This is no time to come ill-prepared to the lower river, be prepared with a good selection of a wide variety of flies.  This fishery is on its last legs for the summer, a recent bump in flows is keeping things fresh down there, but warmer water temps are right around the corner. Be sure to land your trout as quickly and efficiently as you’re able to and take some time to revive them before release.

Taking your time and looking for the subtle signs of feeding trout while putting yourself into a position to make a drag free drift every time will yield positive results river-wide. Have fun and enjoy!


Consistently hot, dry weather has it feeling more like mid-August than mid-June around the Park lately.
No matter the season, be sure to carry your bear spray, and remember that felt wading boots are prohibited in the Park.
Also, be mindful that several million people flock to the world’s first national park every year, and the earlier you can roll through the gate the better.

Firehole River

Unfortunately, we have already reached the point where anglers need to exercise caution when choosing a time and section to fish on the FIrehole due to warm water. Water temps at the gauge in Firehole Canyon have topped out above 70 degrees all week, and bested 80 degrees twice.

On a positive note, water temps at Old Faithful – above most of the thermal influence from downstream geyser basins- have been more moderate with high temps reaching the mid to upper 60’s. Most mornings have seen temps in the 50’s.

So, if you’re planning to fish the Firehole, the best bet to go early in the day, and focus your efforts on the areas upstream of Midway Geyser Basin.

Rising fish can be found in the morning hours with a mixed bag of White Miller Caddis and rusty or olive PMD spinners.

Gallatin River (in YNP)

With snowpack levels rapidly dwindling across the high country, the Gallatin River in the Park is running nearly clear weeks ahead of usual. Flows are low for this time of year, and there is a slight “fishy-green” color to the water.
Water temps are still cold on this high elevation river, and nymphing is the primary game to play. But, the first hatches of PMD’s, Caddis, and Stoneflies will be underway any day.

Gardner River

The Gardner and the Gallatin Rivers are both born from the snowpack high in the southern Gallatin range. One river flows off the west side (Gallatin), the other flows off the east side (Gardner).

Like it’s sister river to the west, the Gardner is also lower and clearer than usual for the middle of June.

Again, nymphing is the ticket, but be on the lookout for the season’s first hatches to begin early here as well.

Yellowstone Lake

If you’re looking to beat this unusual heat, the icy waters of Yellowstone Lake could be a good option.
Leeches and Buggers fished on Type II or III sinking lines will produce some beautiful early-season Cutthroat Trout from Gull Point down to West Thumb.

The frigid waters of Yellowstone Lake demand extra caution, no matter how warm the air temps might be. Be sure to have all of the necessary safety equipment, and know the wind forecast before shoving off. If you access the lake with any sort of watercraft, be sure to get your boat permit and Aquatic Invasive Species Inspection. Locations and other info for boats in Yellowstone can be found HERE.


Flows on Madison have bumped up quite a bit over the past week but are still lower than the 82 year median at Hebgen Dam. The banks and gravel bars are slightly more submerged and getting a boat down the Madison isn’t as noisy as it was a few days ago. We are sitting at 639 at Hebgen, 1050 at Kirby and 1320 at Varney bridge.

Below Quake Lake, the Madison is pretty much clear. There is a slight greenish tinge to the deeper runs, but in a few days, she will be completely clear. The morning river temps have been hovering around 45 degrees, by lunch things have warmed up quite a bit and the fish will get a little more on the bite post lunch. Bankers hours are just fine, no need to get an early start right now. Running down lower on the river is a good idea as there is a bit more water to float in as the tribs are all flowing fairly high at the moment. Nymphing with rubber legs, soft hackle PTs, jigged Hare’s Ears, #10 Prince, splitback PMDS, Shop Vacs and perdigons will produce in the deeper runs. Running the banks with a Chubby and rubber legs is a solid approach, for sure. Caddis are popping and rolling down the river in the afternoon; the trout are giving them full attention so don’t be afraid to toss a dry fly in the likely spots. There are salmonflies in and around Ennis, but nothing crazy just yet. More to come on the Big Bugs, give the shop a call for the most up to date report.


It appears that we’ve entered our typical mid-summer weather pattern a bit early this year.  Chironomids remain high on the menu, with additional insects such as callibaetis, caddis, and damsels set to become more important moving forward.  That in addition to waning runoff will influence how you approach still waters this coming week.  Expect cool and fairly calm mornings and warm/hot afternoons with building winds.  

It is probably the wind that should most profoundly influence how you approach the lakes these days.  Many anglers curse the wind, as it tends to make paddling and casting more difficult and also has been known to foul up a great dry fly bite.  But there are others who have learned how the wind effects the movement of water and food (and trout) on a lake and do all they can to stay out and take advantage of wind-created angling situations.  For instance, wind blown points and islands are often the recipe for the creation of “wind lanes”.  These are the stillwater equivalent of that juicy looking current seam and foam line on your favorite river.  Food is concentrated in these locations, and fish often congregate to feed there.  Less commonly considered are the effects of wind on lake water temperature.  The warm afternoon sun and wind here will typically heat up the surface of the lake, and also push that warm water towards the down wind shoreline.  In some instances, the up wind shoreline will see water from down deeper pushed up towards the surface as well, creating cooler conditions.  These differences in water temperature can influence when and where insect activity is happening, and where the trout feel most comfortable!  Something to consider the next time you are out on the lake


Below are links to the flows in Montana and Idaho as well as. This time of the year flows and the weather are changing daily, if not by the hour. Click the links below for the most up to date information.

Montana River Flows
Idaho River Flows
West Yellowstone Weather Forecast