Early April Snowpack Update and Summer Streamflow Forecast

Early April Snowpack Update and Summer Streamflow Forecast

Early April Snowpack Update and Summer Streamflow Forecast

I’m stuck in a hotel in Utah with THE WORST “HIGH SPEED INTERNET” OF ALL TIME through Sunday morning, so I won’t be posting any pics of likely streamflow as I usually do in these updates. I’ll make another post in 10 days to two weeks.

Winter Summary

We’ve had a topsy-turvy winter and early spring that has left us guessing in terms of predicting summer 2019 conditions. September through early December were cold, wet, and snowy and put us off to a great start. Late December and most of January were warm and dry, and left us worried about conditions. Jan 20 or so through early March had wet spells interspersed with near-record cold. It was -28 in Livingston on March 1, a record for the date by more than 10 days and closing schools for the first time since 1988 (no snow days in these parts). Most of March were warm and dry, while early April was warm and wet until just a couple days ago, when things shifted to cold and wet. It has snowed up in the mountains each of the last three days.

Our mountain snowpack typically peaks between the middle of April and early May, depending on the specific location and elevation. We look on track for this year to follow suit, though with a transition back to warm/dry weather now forecast for late April, I expect we will run a few days early for peak snowpack, particularly for the high elevation locations that look unlikely to build snow in late April as they usually do.

Current Snowpack

Snowpack in our operations area ranges from 102% to 126% of normal. The most important basins for our “core” operations area are the Upper Yellowstone Basin in Wyoming, the Upper Yellowstone Basin in Montana, the Madison-Gallatin Basin in Yellowstone Park, and the Madison Basin outside Yellowstone Park. These basins range from 111% to 126% of normal. The highest percentage is the Madison-Gallatin, which bodes well for a long season on the Firehole, while the lowest is the Yellowstone north of the park, which bodes for a near-normal start to the summer season coupled with streamflows that should remain relatively high and cool throughout the summer.

All in all, we are looking at a somewhat above normal snowpack, which is what we prefer for the summer season even though it leads to a slightly late start for Yellowstone River floats. Remember: we are also floating the Madison and Jefferson this season. While these rivers are not as convenient to Gardiner or Yellowstone Park as the Yellowstone, they are good float options before the Yellowstone is ready.

Current Fishing Conditions

Because the warm weather in early March melted out most snow at low elevations, even if the deep freeze in February has left some ice shelves in strange places, we are now in the full swing of spring fishing. As a matter of fact, I ran two guide trips last weekend and hope to get some more in the next couple weeks.

The top fisheries through April are the Yellowstone, Paradise Valley Spring Creeks, and the lower Madison. The private lakes are just turning on (access might be tough due to snow drifts). Some “new to us” waters like the Jefferson and even the Musselshell will come on in late April. The Missouri is always good in April, on a variety of stretches, and this year is no exception.

Summer Fishing and Streamflow Predictions


We are looking at likely slightly above normal snowpack and streamflows this season. While the timing of the onset of the heavy spring melt has a lot to do with the specific streamflows later in the summer (early snowmelt = early end to snowmelt = lower flows later in summmer), we now feel pretty confident that conditions will be at least near-normal.

In a general sense, this means that we’ll be sweating for places to fish a bit after May 5-10 and until early July, with the most likely bets during this period the Firehole, Madison, and Gibbon in YNP as well as private lakes, the Missouri River, the Madison River, and perhaps the Jefferson River outside the park our best (only) options. On the other hand, once the Yellowstone System both inside and outside the park comes into shape sometime in early July, we anticipate generally consistent fishing and streamflows that are optimal for good fish activity and health as well as angling success. We do not anticipate any closures related to water temperature or flow except on the few rivers that are always too warm in mid-late summer anyway (the lower Madison and Jefferson, basically).

Here’s a suggestion: fishing is going to be generally good this year. If you’re a Firehole Junkie, come anytime in June. If you prefer the northern part of the park and the Yellowstone System outside it, come anytime after about July 4. We had great dry fly fishing through September last year and top-notch subsurface fishing through late October. I expect this year to be just as good, with the standard caveats about thunderstorms muddying the river and the few days that are 97 degrees and sunny out being the exceptions.

More detail on individual fisheries follows. The fisheries are listed within their river basins, with basins listed in the approximate order in which they drop out of the spring runoff. Yellowstone Park fisheries are given first, then Montana fisheries.

Reminder: The Yellowstone Park general season opens May 25 this year!

Madison River Drainage (YNP)

Firehole River

This is going to be a good year for the Firehole. The park opener falls early, so there’s a good chance the river will not have even reached peak runoff yet for the first few days of the season. Fishing in the last few days of May and early June will be best if it is cool, which will slow the runoff. There may be a few days of “meh” clarity here, even between Biscuit Basin and Midway. These are most likely prior to June 5. The best fishing will be June 5–20. Afternoons will get shaky after the 20th, but mornings should be good through June barring extremely hot weather. It’s pretty likely that Biscuit Basin down to but not including Midway Geyser Basin will continue fishing in the mornings until at least July 4 and maybe July 10.

Madison River

Will probably become fishable in the first week of June unless runoff is very slow, in which case it may fish at the opener, go out for a few days, and then be back no later than June 10. The best fishing will be in the latter half of June. It’s very likely that mornings will be fine through mid-July. It’s possible but unlikely that mornings will be fishable through July, meaning the Madison doesn’t have a down period this year (last time was 2011 or 2014). This depends on fairly cool summer weather and some rain.

Gibbon River

Will probably not fish on the opener unless it’s cold, in which case it will fish and then go out. Unlikely to be consistent before sometime between June 5 and June 10. The best fishing will occur in the latter half of June in the canyon or June 20 through July 4 from Norris to the canyon. Below Norris should fish at least in the mornings through July 15 and may fish all summer, though there will be better “small fish and numbers” fisheries than the canyon all over the place and better “big spooky” fish in the Lamar Drainage.

The small fish water between Virginia Cascade and Norrris will not be ready before June 20. This is in contrast to the swarms of campground folk who’ll be crawling all over Norris Meadow while it’s still a giant swamp. The water from the headwaters down to Virginia Cascades is currently not a viable fishery while fluvial grayling and westslope cutthroats are introduced above the falls; this water was poisoned in 2017 to remove non-natives.

Other Fisheries

Firehole tributary creeks will come in during the last ten days of June or so. Reminder: Grebe Lake and the upper Gibbon System are currently not viable fisheries due to the poisoning and introduction noted above.

Yellowstone River Drainage (YNP)

Upper Yellowstone (Above the Lake and Lake to Falls)

Opens July 15, as always. The best fishing will be in the two weeks after the opener, but there’s sufficient water in the system and enough cutts in the lake rebounding from the lake trout that there’s some utility in fishing through August, particularly from the lake to Sulphur Cauldron.

Grand Canyon (Falls to Lamar)

May be fishable with nymphs and streamers on the opener if and only if May 15-25 are cool. If it’s clear then, holy biscuits… After that, will blow out and probably not reach peak runoff until June 20-25, though this water becomes fishable the instant it begins to drop (since the loose mud will have been scoured from the canyon walls by that point). Again, nymphs and streamers for a while after that. The best fishing will occur from about July 10 through September. Salmonflies here and there as soon as it clears, but heavy in the second and third weeks of July.

Black Canyon (Lamar to Gardiner)

No way it’s fishable until at least June 25, and July 4 is not 100% safe (cross fingers, daddy has floats). The Salmonflies will pop between the second week of July and the end of July, with the peak emergence near Gardiner around July 10 and the peak at the upper end of the canyon a week or so later. The best fishing will occur from the Salmonfly hatch through late September, but the portions near Gardiner are worth a shot right until the park closes in early November.

Other Fisheries

Tributary streams will generally not be fishable until at least early July, with August best. Those flowing out of lakes are the main exceptions. Blacktail (beginner brookie creek) will be fishable in spots by the 25th of June. Small lakes will be reachable around June 10 and best from June 15 to July 15. Yellowstone Lake may well still have ice on the opener, but it’ll melt within a few days. The fishing will be best prior to the middle of July.

Gardner River Drainage (YNP)

Gardner above Osprey Falls

Likely too high even if it’s clear until at least July 10. The best fishing will be July 20 through August.

Gardner between Osprey Falls and Boiling River

Nymphable anytime it’s clear (a few cool days will do it), but tough and inconsistent. It will ‘really’ become fishable around the beginning of July. From this point, it’s a good choice provided it’s not cold all the way until late October.

Gardner between Boiling River and the Yellowstone

Nymphable whenever there’s a foot of visibility so long as you like heavy #6 stoneflies. There is a very good chance for a couple days of fishing in late May, essentially the early stages of the high elevation melt. This is tough and physical fishing. Will ‘really’ become fishable between June 15 and June 25, but still be physical into early July. The best fishing will be the early physically exhausting and dangerous nymphing, the Salmonflies in the first week of July(ish), and the fall fishing from about September 20 through the end of the park season.

Other Fisheries

Joffee Lake and the Swan Lake Flat Sloughs will be cold and sloppy but fishable on the opener. Otherwise, tributary creeks will begin dropping into shape between June 20 and the end of the month, and be good in July and August.

Lamar River Drainage (YNP)

Lamar Mainstem

Almost no way it’s fishable before July 4, and it might easily be the 10th. The latter half of July through the middle of September will be best.

Soda Butte Creek

Same as the Lamar, but more crowded.

Slough Creek

Slough might be fishable with streamers on the opener. This happens about one year in five, and the early opener is good for that. If so, go there and swing meat. More likely, it becomes fishable in the first week of July and is best from the 10th through the month, getting tougher and tougher but still producing for skilled anglers until the middle of September or a bit later.

Other Fisheries

Other Lamar System tribs are likely to become fishable sometime in the first ten days of July. All are best before the end of August, since the larger fish tend to live in one of the bigger rivers. Trout Lake should be ice-free and be as good as it ever gets on the opener.

Missouri River (MT)

Headwaters to Canyon Ferry

While technically open for rainbows now, and can turn out some huge ones on streamers when it’s clear, we think of this as summer carp and fall brown trout water. As such, skip it until late July.

Canyon Ferry Tailwater and Hauser Tailwater (“Land of the Giants”)

Fishing now, and unlikely to get quite so high as last year. Think pink. Peak inflow and therefore highest water levels are likely in May, probably mid-month. I will be running power boat trips here again beginning in spring 2020. I would love to get a bunch of early deposits…

Holter Tailwater

There’s a reason this is the busiest water in Montana in May and the first half of June. It’ll get high, but stay clear, and should fish well all spring. The dry fly bite will probably be so-so at best in May due to fairly high water.

Madison River (MT)

“Between the Lakes”

Fishing now, though requires post-holing through snow to reach. Think pink, midges, and eggs. Any warm weather will bring mud in from tributaries, but the top portion of this short chunk of river, the stretch right below Holter Dam, always remains clear.

Quake Lake to Ennis Lake

Fishing now and relatively snow-free as of Tuesday. A good bet with stonefly nymphs, midges, eggs, and maybe some BWO. Will get high enough that bank fishing will be tough to nonexistent, and probably won’t be “good,” from late May until the middle of June, but seldom becomes truly unfishable.

Ennis Lake to Three Forks

Will probably get fairly high, but that doesn’t really hurt this water. The bigger issue is mud out of Cherry Creek, which may be enough to dirty the river in early May. Otherwise, this water is a good choice. We’re running trips here for the first time this year, and this is where we’ll be floating the most from May 10 until the Yellowstone clears. There should be enough snow up high that this water will fish at least in the morning through July 15, though watch out for the bikini hatch once July rolls around.

Other Fisheries

The lakes should ice-out in early May and be good out of the gate.

Jefferson River (MT)

Has a short runoff that should be done by June 25. The fishing is best in late April and early May before the mud and for a week or two after the mud but before it gets hot. It can be a narrow window, alas.

Yellowstone River Drainage (MT)

Gardiner to Point of Rocks

Fishing well now (two guide trips out over the weekend) and should continue to stay strong until early May except when early surgest of low-elevation melt hit the river. Hopefully the heavy runoff holds off until May 10 or so. If it does, we’ll have a good Mother’s Day Caddis hatch. If it doesn’t, we’ll have chocolate stew from the time it blows until at least the last week of June, and I’m now thinking the first week of July is a better bet. The fishing will be good from then until early November. Salmonflies should take place July 4-10 or so.

Point of Rocks to Carter’s Bridge

It’s always a question mark if this water clears before, during, or after the Salmonfly hatch. It should clear near the end of June or in the first week of July, with Salmonflies at about the same time. We should have enough water this year that this stretch stays good all summer, with the best big brown streamer action in the latter half of July (with numbers of fish on caddis) and the best attractor/terrestrial fishing for both numbers and bigger fish in the latter half of August and first week of September.

Carter’s Bridge to Laurel

The Shields River has been pumping mud in already, so it’s a good question of how most of this water will fish pre-runoff. It might now. This water is “burly” enough it needs more time to drop into shape than the water above. Look to fish here beginning July 10-15, with the best fishing for the first month on caddis and streamers and on streamers and BWO after Labor Day. There may be some days this stretch gets too warm, generally the last week of July and first week of August. This depends on temps and precip. If summer is cool/damp, no problem. A week of 90+ daytime highs and you should go further upstream, even if this is the “lunker hunter” water on the Yellowstone.

Boulder River

We will be running floats here for the first time this year. Runoff will recede around July 1 and flows will remain high enough to float for about a month thereafter. This whole period will offer good attractor dry-dropper fishing, though every guide in Livingston with a raft likes to fish here at that time (including yours truly).

Stillwater River

Similar to the Boulder, but further away (2hr from Gardiner, at minimum), bigger, and less-crowded. It’ll stay high enough to float until around Labor Day.

Private Lakes

Usually good already, but the snowdrifts at low elevations make them something of a question mark. I’d hold off until April 20 or 25. After that, good fishing until late June for Story and late July for Burns, with warm water a question mark for good fishing from those points until about Labor Day. Merrell had another fish kill last year and so is off the table for 2019.

Paradise Valley Spring Creeks

Good bets for a few more weeks and then again after June 15-20, when the PMD start. Runoff does not impact them.

Other Fisheries

Dailey Lake is a reasonable bet for a few huge mutant holdover stocked fish and maybe some smaller recent stockers. Tributary creeks won’t be ready until July 10 or so and will be best July 20 through about September 10. We are playing with some access on the Shields River, which will have good streamflows for the third year in a row, a rarity. Stay tuned…

Gallatin River Drainage (MT)

Park Boundary to Gallatin Gateway

Fishing now, particularly between Big Sky and Gallatin Gatewaay. Expect runoff to hit sometime in the first half of May, though this water can have a short window of fishability here and there during this period, especially between the boundary and the Taylor Fork confluence. Will drop from runoff in early July.

Gallatin Gateway to Gallatin Forks

Good now, particularly at the upper end. Will blow out in early May and generally be too warm once it drops from runoff in July. There’s a reason the water upstream gets more pressure.

Gallatin Forks to Three Forks

Really only a fall float fishery. We’ll run a trip or two here after Labor Day for diehards who want to see a new river and are okay with tough fishing for very small numbers of big guys in exchange for low crowds.

East Gallatin

A good choice now when it’s clear. We may run some trips here this year now that I’m in Livingston. Will experience pulses of runoff whenever it’s warm, especially if it’s warm and rainy. The heaviest runoff will be in May and early June. Will drop out of runoff in late June.

Other Fisheries

The various lakes will be hard to hike into before late June, but should be good then. Tributary creeks besides the East Gallatin will be roaring until about July 10 and best July 20 through Labor Day.

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