Yellowstone trout in prime window as paddlefish season brings new rules

What's Biting

What's Next

With the Yellowstone running at 2,800 cfs near Corwin Springs as of May 30 (USGS gauge 06043500), flows are in a range that should support productive drift-boat fishing along the middle and lower corridor. Some wade-fishing access may be opening up as well, depending on which reaches have cleared and settled. As snowmelt from higher elevations continues to taper through the first week of June, flows may ease further. Watch for dropping and clearing water, which historically triggers more aggressive dry-fly action on PMDs, caddis, and golden stones. Visibility and water color are worth checking before you commit to a specific stretch.

Flylab (Substack)'s review of Yellowstone hatch data spanning three decades is worth heeding this week: emergence timing has shifted noticeably over the years, so anglers shouldn't rely solely on older hatch calendars. Late May through mid-June on the Yellowstone typically brings golden stonefly activity, PMD hatches mid-morning through afternoon, and opportunistic caddis in the evenings. Timing your session around current river conditions and time of day matters more than any fixed date on the calendar.

The Full Moon on May 31 is worth factoring into your planning. On freestone rivers like the Yellowstone and Missouri, full-moon phases are often associated with heightened feeding activity during low-light windows at dawn and dusk as trout key in on those transitions. Consider early-morning starts through the weekend rather than waiting for mid-afternoon sessions.

On the Missouri River, the paddlefish snagging season is in full swing, and MT FWP Fishing News has confirmed that new tagging requirements are in effect for 2026. The old colored plastic tag system is gone. Anglers must complete the updated tagging process before the carcass is moved, cleaned, or filleted. Review current MT FWP guidance before your trip to avoid compliance issues during the harvest.

The Missouri's walleye and sauger fisheries typically hold up well through June in tailwater stretches, though no specific current bite reports are available from our sources. Bull trout fishing, where regulations allow it, warrants extra caution this season given MT FWP's active conservation focus. Check current regulations before targeting any bull trout.

Context

Late May on the Yellowstone and Missouri river systems marks the heart of the spring transition: snowmelt runoff is peaking or just past peak, water temps are climbing toward the range where trout become reliably active, and insect hatches begin to accelerate. Flylab (Substack)'s Yellowstone hatch retrospective, authored by John Juracek, co-author of the original 'Fishing Yellowstone Hatches,' is one of the few sources in this report with direct regional relevance. After 33 years of on-water observation, Juracek notes that hatch distributions have shifted in ways that make historical charts unreliable guides for modern anglers. That context is directly useful right now: don't assume golden stones and PMDs are hitting on the same schedule they did 10 or 20 years ago.

At 2,800 cfs on gauge 06043500 near Corwin Springs, the Yellowstone is running at a generally fishable level. The river can spike well into the tens of thousands of cfs during heavy runoff years, shutting down wade access for weeks at a stretch. A reading in the low thousands heading into June suggests runoff has either been moderate this year or is already tapering, which could translate to earlier-than-average wade-fishing access on the upper and middle river. That is a cautious inference based on available gauge data, not a confirmed trend.

On the Missouri, the annual paddlefish season has historically ranked among Montana's most anticipated spring fisheries, drawing anglers from across the region. MT FWP Fishing News confirms the 2026 season is underway with updated tagging procedures. No comparative data on run size or catch rates is available from this report's sources. MT FWP is also actively working on native bull trout recovery at Swan Lake, where invasive lake trout have been eroding the native population over time, a conservation concern worth keeping in mind across the broader region.