Green River tailwater trout in prime late-May form as flows hold moderate

What's Biting

What's Next

Over the next two to three days, the dam-controlled release on the Green River means water temperature and flow will shift only modestly unless Bureau of Reclamation operators adjust output for downstream irrigation demand, a common occurrence in late May as agricultural draws increase. If releases edge above 1,500 cfs, wading the A-section becomes more challenging and a drift boat picks up the slack. Check the USGS gauge 09234500 in real time before you launch.

At 51°F, late-May hatches on the Green River typically cycle through midges throughout the day, with Pale Morning Dun (PMD) emergences firing during the warmer midday window, roughly 11 a.m. to 2 p.m., when surface temps tick a degree or two higher. MidCurrent's Tying Tuesday: Surface, Film, and Open Water feature this week covers patterns designed to work every feeding lane from the surface film to open water, which maps well to Green River conditions where fish work the column simultaneously. CDC-style emergers and film-riding dries become relevant once PMDs appear.

Caddis activity typically ramps up through late May and into June on this tailwater. The standard presentation moves through larvae and soft-hackle emerger nymphs before transitioning to elk-hair or parachute caddis dries once the hatch fires mid-afternoon. This is on-schedule for Western tailwaters at this latitude and elevation.

The First Quarter moon this week produces moderate solunar activity. Expect the most consistent feeding windows in the early morning for pre-hatch nymphing, and again in the last two hours of light when larger brown trout drop their wariness. If you're targeting trophy fish in the 20-inch-plus class that the Green River's B and C sections are known for, low-light edges remain the best bet.

Weekend timing looks favorable. Plan to be on the water by 9 a.m. to work nymphs through prime runs ahead of the PMD emergence, then hold position through midday if bugs are showing. Confirm gauge readings Friday evening before making the drive.

Context

The Green River below Flaming Gorge Dam is one of the most consistent tailwater fisheries in the Mountain West precisely because dam releases buffer the wild temperature swings that define freestone rivers at this latitude. In a typical late-May period, water temperatures at gauge 09234500 run between 48°F and 54°F. Today's reading of 51°F sits squarely on the seasonal median, suggesting no unusual thermal event upstream.

Flows at this time of year tend to run higher than late-summer levels as Flaming Gorge releases increase to meet downstream irrigation demand. The 1,210 cfs reading this morning is moderate by late-May standards: not the shoulder-high wading you sometimes encounter at 2,000-plus cfs, but also not the low, ultra-clear, highly pressured conditions of August. This is a productive middle ground, enough current to keep fish actively feeding in defined seams without pushing waders off their feet.

Historically, late May marks the start of the Green River's most reliable dry-fly season. PMD hatches are the marquee event, typically peaking in late May and running strong through June, with caddis following close behind. Both hatches tend to produce the most aggressive surface takes of the year on this stretch. Trout Unlimited's ongoing conservation advocacy across Western tailwaters underscores the broader regional importance of fisheries like this one.

No angler-intel feed in this week's data covers the Green River specifically, so direct year-over-year comparison is not available from these sources. Conditions as of May 25 read as on-schedule: gauge data shows nothing unusual, and the hatch calendar aligns with what anglers in this corridor typically plan their late-May trips around.