Hopper season opens on MT blue-ribbon waters amid drought alert

What's biting

What's next

**Conditions over the next 2–3 days**

With the USGS gauge reading 1,050 cfs and post-runoff flows on a gradual summer decline, clarity on the Yellowstone system should be good to excellent. Absent a significant afternoon thunderstorm — common in Montana in July — expect levels to hold or ease slightly lower as snowmelt contribution fades entirely. Lower flows concentrate trout in predictable lies: seams below riffles, undercut cutbanks, and the heads of deeper pools. This is an ideal window for methodical dry-fly and nymph coverage.

The critical variable is water temperature, and it cannot be overstated given this summer's forecast. MT FWP explicitly flagged above-normal heat heading into the season, and Trout Unlimited is clear on the threshold: when afternoon readings consistently push above 68°F, trout feeding shuts down and handling mortality rises sharply. Until you can confirm midday temperatures are safely below that mark, build your plan around the first two hours of daylight and the 90-minute window before dark. If afternoon temps are elevated, consider pivoting to the Missouri tailwater below Canyon Ferry Dam — dam-regulated releases maintain cooler, more stable water regardless of air temperature.

**What should turn on soon**

July traditionally marks the opening of hopper season across the Yellowstone drainage, and this year's early low-water conditions could accelerate that transition. Grasshoppers become clumsy along bank vegetation as summer heat builds, and large brown trout keyed to the bank are the calling card of this fishery. Foam hopper patterns drifted tight to grassy cutbanks — especially on breezy afternoons when naturals get blown onto the water — are worth threading on as you move further into the month. Morning caddis and PMD activity should remain steady on both the Yellowstone and Missouri systems through mid-July.

On Canyon Ferry, walleye are accessible and the fishing window is wide. Per MT FWP, keeping smaller fish actively supports the quality of the fishery — jigs and live bait worked along rocky points and depth transitions are typically productive through summer. Check current MT FWP regulations for any applicable slot or size limits before harvesting.

**Weekend planning**

Use the TroutCast tool (usgs.gov/apps/troutcast) before making the drive — it was built specifically to forecast drought stress on Montana's named trout rivers and will flag any voluntary catch-and-release or no-fishing advisories as conditions evolve. If the Yellowstone is showing thermal stress in real time, the Missouri tailwater is your best mid-summer alternative.

Context

A typical early-July Yellowstone pattern sees flows somewhere in the 1,200–2,500 cfs range, depending on the prior winter's snowpack and spring rain totals, with the peak runoff pulse having crested in late May or early June. At 1,050 cfs on July 5, this reading lands below the historical mid-range for this date — consistent with what MT FWP called out directly: a below-normal snowpack winter and a summer weather forecast that trends hotter and drier than average. In a high-snowpack year the Yellowstone can still be running 1,500 cfs or more in early July; reaching 1,050 in the first week of the month suggests the system shed its runoff pulse faster than normal and is trending toward late-summer low-water conditions ahead of schedule.

That timing carries real implications for trout. Earlier low-water onset compresses the prime early-summer fishing window and accelerates warm-water stress risk. MT FWP's proactive launch of the USGS/Montana State University/NOAA TroutCast tool — specifically designed to forecast drought impacts on blue-ribbon trout rivers and deployed June 1, 2026 — is a meaningful institutional signal that regulators anticipated a challenging summer. Trout Unlimited's broader drought guidance reinforces this: voluntary angler restraint during midday heat is increasingly the norm, not the exception, on Montana's premiere trout waters in seasons like this one.

For Canyon Ferry and the Missouri system, the FWP walleye advisory is a standard summer management tool the department uses when juvenile fish outnumber available forage — not a red flag for the fishery's overall health, but a useful reminder that the quality of Canyon Ferry walleye fishing responds directly to angler harvest behavior. In recent years the reservoir has been building toward a larger average fish size through exactly this kind of voluntary-keep messaging.