Rock Creek Fishing Report, May 18, 2026

The whole Missoula-area system is in spring-runoff mode. The Bitterroot peaked near 11,600 CFS on Friday 5/15 and has been dropping with the cool weekend; the Blackfoot is dropping from a 7,000 CFS peak (4,600 this morning); Rock Creek is around 1,500–1,800 CFS and still high; the Clark Fork is high and off-color, with the upper river fishing better than the lower. Tributaries open Saturday 5/16 this year. The week ahead clears up Monday with highs climbing back into the 60s — fishing should improve daily as flows drop and clarity returns. Best window most days is roughly late-morning through afternoon.

Conditions at-a-glance: High and off-color · visibility decent and improving · water temp ~47–49°F at Clinton · ~1,500–1,840 CFS · Grizzly Hackle: 1/5

Warning: The main stem is too big and fast to fish right now. Focus on small side channels; floating is still open but spot-check anything that feels uncomfortable. Wade carefully. Tributaries do not open until Saturday 5/16.

Conditions. Rock Creek is high but relatively clear and continuing to drop. The cold snap has postponed the big-bug hatches, but small bugs are coming off in droves in the evenings. Upper sections are fishing better and have better clarity. Focus subsurface with big nymphs and streamers, or on the small side channels.

Best techniques.

• Nymphing is the consistent producer — heavy rigs with big stoneflies. Pat's, TJ Hookers, double bead stones, Zirdles, San Juan Worms, Wire Worms, and Squirmy Worms with a smaller dropper like a perdigon or Duracell.
• Dry-dropper with a Chubby or foam salmonfly up top, PT, TJ, or Duracell underneath.
• Streamers — sculpin patterns, Mini Dungeons, a good bugger, or a Bighorn Bugger fished slow and tight to undercut banks, root wads, and darker, deeper slots.

Hatches

BWOs, March Browns, Caddis starting to mix in, and the occasional drake. Big stones still pending. Good dry options when fish are up: X-Cadis, Parachutes, Purple Haze, Last Chance Cripple, and Tilt Wing BWO. Blackfoot River Outfitters' featured dries: MFC Hot Spot Para-Wulff- Brindle, Flash Cripple- Green Drake, Flash Cripple- Grey, Jake's Green Drake, Carlson's Purple Haze, Stranahan's Brindle Chute, and Chubby Chernobyl- Salmonfly.

The Fly Box

Nymphs: TJ Hookers, San Juan, Wire Worms, Squirmy Worms, Duracell

Dries: Chubby, Purple Haze, Last Chance Cripple, Tilt Wing BWO, Jake's Green Drake, Brindle Chute

Streamers: Mini Dungeons, Bighorn Bugger

Outlook. Cool and wet weekend in the canyon — highs in the 40s and snow showers likely Saturday and Sunday. Conditions improve Monday with temps pushing back into the 50s, reaching near 60 by Thursday. Salmonfly season is on the horizon; conditions now are poor but the next two weeks should turn it around.