If you’ve been waiting for a sign to dust off the fly rod and brave the elements, this is it. May wrapped up with a glorious stretch of skuzzy weather—which, in the fly-fishing world, is just code for “perfect trout conditions.” The latest report (from June 4, 2026) by Big Sky Anglers breaks down exactly how this recent soaking rain gave Yellowstone’s rivers a much-needed boost, triggering some killer mayfly hatches while pushing the park’s meager snowpack to its final stand.
Here’s the latest from Big Sky Anglers:
May wrapped up with a full weekend of cool, skuzzy weather across Yellowstone, complete with temperatures in the 40s and a steady soaking rain. At this point in the spring, it was a welcome change. The moisture provided a much-needed boost to the rivers while also triggering hatches of Baetis and Pale Morning Dun mayflies.
Forecasts call for a return to warmer, windier conditions before another round of wet weather arrives early next week. That warmth will likely finish off what remains of the snowpack at the Black Bear SNOTEL site atop the Madison Plateau. Less than 10 inches of snow remain on the ground, and it would be surprising to see any of it survive beyond the weekend.
With the last of this year’s meager snowpack fading away, the Firehole, Gibbon, and Madison now depend on cool, wet weather to keep water temperatures within a safe range for trout. Fortunately, the forecast remains favorable over the next week, but anglers should continue to carry a thermometer and closely monitor water temperatures as the season progresses.
Elsewhere in the park, runoff is still in full swing with many of our favorite summertime fisheries running high and dirty. The season continues to progress quickly and trend ahead of schedule. So, stay tuned here for updates over the coming weeks as conditions improve and more fisheries come online.
FIREHOLE
Warm, windy conditions will reduce the potential for strong mayfly hatches and limit opportunities to find rising fish. Your best bet to find dry fly targets will be in the mornings and evenings with pale morning dun spinners (rusty and olive, size # 16-18), as well as nectopshyche (white, size #14-16) and hydropsyche (tan, size # 16) caddis.
On warm, calm mornings, you may see pmd spinner falls mixed in with a sparse emergence as early 8:00am.
As always, swinging soft hackles through the riffles is a fun and productive way to spend the afternoon, or any time when fish aren’t feeding on the surface.
MADISON (in YNP)
If you’re headed into the park from West Yellowstone to fish the Firehole on a warm, calm morning this week, you’ll be presented with a conundrum. You have to drive by miles of beautiful dry fly water on the Madison to get there. Such a dilemma!
Pale morning dun spinner falls will also bring fish to the surface on the Madison, as long as the wind stays down, or at least remains relatively light.
If you’re planning to spend the morning in Yellowstone and the afternoon elsewhere, perhaps on the Madison below Quake Lake or the Henry’s Fork, don’t overlook the Madison in the Park. It’s a convenient place to sneak in a few hours of fishing before the wind picks up and the crowds begin to build.
GIBBON
Not much has changed on the Gibbon this week. It continues to offer a diverse range of fishing opportunities between its rough-and-tumble canyon stretches and slow, meandering meadow sections. Pocket water above and below Gibbon Falls remains an excellent option for anglers fishing dry-dropper rigs or indicator nymph setups for brown, rainbow, and westslope cutthroat trout. Upstream, the meadow reaches provide a completely different experience, rewarding careful presentations to subtle risers tucked beneath grassy undercut banks.
Lakes
Ice out has occurred on many of our favorite lakes in the Park including Shoshone, Lewis, Grebe, and Yellowstone. This is a great time to find fish cruising the shallow areas close to shore hunting for leeches, damsel fly larvae, and callibaetis nymphs.
As always, If you venture into any of the back country lakes, be sure to bring your bear spray, and be bear aware anytime you’re fishing in Yellowstone Park.
Stay Safe in Bear Country
- Stay 100 yards away from bears at all times.
- Carry bear spray and know how to use it.
- Be alert. See the bear before you surprise it. Watch for fresh tracks, scat, and feeding sites (signs of digging, rolled rocks, torn up logs, ripped open ant hills)
- Make noise
- Hike in groups of three or more people.
- Don’t hike at dawn, dusk, or at night, when grizzlies are most active.
- Don’t run from a bear.
Now that we have reached the general open season in the Park, more options will come into shape every week. If the current trend continues, many of the fisheries we start visiting in late June might be worth checking out over the coming weeks. Keep a close eye on the current weather and water conditions, and always feel free to give us a shout in the shop (406) 646-7801 for the most up-to-date info.