Drought Watch Looms as Trout Season Peaks on Yellowstone and Missouri

What's Biting

What's Next

With MT FWP confirming low snowpack and a hotter, drier summer forecast, the next several weeks will define the season on both the Yellowstone and Missouri. The immediate window, this week and weekend, is likely still productive on both systems, but the trajectory points toward tightening thermal windows as June advances.

On the Yellowstone, flows at 1,810 cfs (USGS 06043500) are below a typical early June runoff peak, suggesting the snowmelt pulse has largely passed. As flows continue to recede, clarity will improve in the upper river, opening the door for dry fly work. Stonefly hatches are the calendar anchor for the upper Yellowstone in June; if salmonflies are winding down, golden stones will carry the hatch downstream through late June. Fish stonefly dries in evening and early morning when trout are least heat-stressed, and be prepared to scale down to caddis and PMD patterns during the heat of the day.

The Missouri below Holter Dam operates as a tailwater, insulating it from the snowpack deficit better than the freestone Yellowstone. June is prime PMD season on the Missouri, and midday hatches are the main event. Flylords Mag highlighted Headhunters co-founder Mark Raisler, who has moved clients off indicator nymphing this season entirely; that is a meaningful on-the-water signal that fish are looking up. A PMD dry or soft hackle fished in the film during hatch windows should produce through the weekend.

Plan around temperature. No water temperature data is currently available from the Yellowstone gauge (USGS 06043500), but with air temps building, probe temperatures before committing to a full afternoon session. Trout feeding quality drops significantly above 68 degrees. The Last Quarter moon this week means darker nights and reduced overnight lunar pressure, which often pushes trout to feed more aggressively in the first hour of daylight; target that early window.

Paddlefish snagging on the traditional Montana spots is active, with MT FWP's new big-game-style tagging requirements now in effect. Review the updated harvest rules before heading out; tagging must be completed before the carcass is moved or cleaned.

Watch MT FWP's TroutCast tool, launched June 1, for real-time drought risk assessments on specific river reaches. If voluntary closures or temperature-triggered advisories appear on the platform, treat them seriously. Protecting fish through the warmest stretch of a drought year carries real implications for fall fishing quality.

Context

Early June on Montana's blue-ribbon rivers is historically one of the year's most compelling fishing windows: the brief period when runoff has cleared, hatches are firing, and summer's worst heat has not yet arrived. In a normal snowpack year, the Yellowstone at this gauge typically runs considerably higher at this date, with peak runoff flows often pushing well above 3,000 cfs through May before settling into a more fishable range in early June. Reading 1,810 cfs on June 8 places this year below that historical average, consistent with MT FWP Fishing News' own assessment of a low-snowpack winter.

MT FWP's launch of TroutCast and their virtual townhall on summer drought threats signal an unusual level of institutional concern for this season. As Hatch Magazine notes in their guide to fishing through drought, prolonged low water and elevated summer temperatures force trout into a narrowing set of thermal refugia: deep shaded pools, spring-fed tributaries, and cold tailwater reaches near dam outflows. The Missouri below Holter Dam is better positioned to hold quality fishing deep into summer than the freestone Yellowstone for exactly this reason.

Bull trout conservation adds important regional context. MT FWP Fishing News has documented the slow decline of bull trout from historic strongholds like Swan Lake, where invasive lake trout are outcompeting the native species. In a drought year that concentrates fish in fewer refugia, competitive pressure on native trout can intensify further.

For historical perspective on the paddlefish fishery: MT FWP's rollout of new big-game-style tagging requirements this season reflects a broader shift toward data-driven harvest management in Montana, mirroring how big game tracking has evolved over decades.

Overall, 2026 appears to be a compressed season for the Yellowstone's prime freestone fishing, arriving earlier and likely ending sooner than an average year. The Missouri tailwater offers the most reliable trout conditions through midsummer, and anglers planning a Montana trip should weight their calendar toward June rather than July if conditions continue on the current trajectory.