Rock Creek Fishing Report, July 17, 2026
2026-07-17 (July 17, 2026)
Regional summary
Not much has moved on the calendar in the three days since the last report, and yet the season keeps inching forward. Every valley gauge is a notch lower than it was, the water keeps clearing, and the bug board has finished its handoff: the big stoneflies that carried June are essentially done, and trout have settled into a steady summer diet of PMDs, Yellow Sallies, caddis, Green Drakes on the gray days, and the first real wave of terrestrials. The one variable running the whole show is heat. Mornings still start cool and friendly, but midday water is now creeping into the upper 60s and low 70s on the valley rivers, so the productive clock has slid hard toward early and late. The other new wrinkle is a regulation change worth knowing before you load the boat: the Blackfoot closed to floating from Weigh Station down to the I-90 bridge on July 15, running through October 31. Carry a thermometer, start at first light, get fish in and released quickly in the warm afternoons, and check Montana FWP for restrictions before every trip, since nothing was posted when the shops filed but a hot week can flip that overnight.
At a glance: Wade fishing only (float ban in effect July 1 through Nov. 30) | dropping to prime wading, good clarity | ~65°F midday, cooler than the valley rivers | ~580 CFS near Clinton (live USGS, down from ~618 last report) | GH rating: 4/5 | Best window: early and late
The creek has dropped into prime wading flows, though it is still swift enough that you cannot hop across it and the streambed gets slippery in late summer, so take crossings seriously. Clarity is good, which puts a premium on a drag-free drift. Because it runs cooler than the bigger valley rivers, Rock Creek is a smart pick during this hot stretch, but that is no excuse to overplay fish in the afternoon. Salmonflies and Golden Stones have handed the lead to PMDs, Green Drakes, Yellow Sallies, and caddis, with drakes best under cloud and the evenings bringing thick caddis and PMD spinner sippers close to dark. Work the riffle corners, boulder pockets, soft inside seams, shaded slots, and the cushions behind heavy rock. Remember this is a boots fishery now: boats are off the creek through November 30, so plan on wading only.
Best techniques
- Dry-dropper is still the most consistent tool: a #10-12 Chubby Chernobyl or Water Walker up top with a #16-18 PMD nymph, Frenchie, Jigged Hare's Ear, Caddis Pupa, or purple Perdigon below. Pat's RLs, TJ Hookers, Hot Spot Stoneflies, and Split Case PMDs round out the bench.
- For the Green Drake windows, cloudy and drizzly is the magic weather. In the afternoon, downsize to a Plan B, Stimulator, Purple Haze, or Parachute Adams in #12-16 and hunt risers in the softer seams. When picky fish key on spinners, a Ms. Tickle Cripple or Para-Wulff placed right above them earns the eat.
- Between hatches, strip or swing a Sparkle Minnow, Sparring Partner, Thin Mint, or a small olive or black streamer through the deeper slots. Kingfisher's Rock Creek regulars always know which mile markers are on; it costs nothing to ask on the way out.
Hatches
Golden Stones still worth a bug up top but fading, PMDs and Green Drakes owning the afternoons, Yellow Sallies steady, nocturnal stones early, and caddis plus PMD spinners running the evenings.
The Fly Box
Nymphs: Pat's Rubber Legs, TJ Hookers, Hot Spot Stoneflies, Frenchies, Split Case PMDs, Jigged Hare's Ears, Caddis Pupa, Perdigons, Pheasant Tails, Green Drake Nymphs
Dries: Chubby Chernobyls, Water Walkers, Golden Stones, Stimulators, Plan B, PMD Spinners, Green Drakes, Yellow Sallies, Purple Haze, Ms. Tickle Cripple, Para-Wulff, Parachute Adams, Elk Hair Caddis, X-Caddis, Ants and Beetles
Streamers: Sparkle Minnows, Sparring Partners, Mini Dungeons, Thin Mints, Woolly Buggers
Outlook. Hot with a heavy thunderstorm chance today, another warm day Saturday, then a mix of sunny 80s and a few cooler, cloudier 60s-and-70s days into next week. Storms could briefly cloud the creek, but otherwise this stays excellent wade fishing, best early and late as the weekend heat builds, and the cloudy days are your green drake days.
Sources and Thanks
| Shop | Report date | Coverage |
|---|---|---|
| Kingfisher Fly Shop | July 17, 2026 | All four rivers (freshest) |
| The Missoulian Angler | July 16, 2026 | All four rivers |
| Blackfoot River Outfitters | July 10, 2026 | All four rivers |
| Grizzly Hackle | July 10, 2026 | All four rivers |
| Lightweight Fly Shop | July 5, 2026 | All four rivers, consolidated weekly |
