Green Drake

Latin: Drunella grandis (Western Green Drake — the Montana species) Family: Ephemerellidae Sizes: #10 – #12 Where: Western North American freestones — Bitterroot, Blackfoot, Rock Creek among the best Montana waters

Overview

The Green Drake is one of the year's most-anticipated dry-fly hatches in the West. A large olive-green-bodied mayfly with smoke-colored wings, drakes emerge over a relatively short window — typically two weeks in mid-to-late June. The hatch is mid-afternoon and trout key on them aggressively because of the size. The Kingfisher 6/18/2025 report noted Drakes following on the heels of the receding salmonfly hatch, with "Extended Body Green Drake" patterns getting "even the pickiest of eaters."

Life cycle and angler relevance

Drake nymphs are crawlers that live in slow-moderate currents. Hatching happens at the surface, with adults riding the water for an extended period before takeoff. Cripples and emergers are deadly during the actual hatch. The hatch typically peaks in early afternoon (1–4 PM) and drops off as the sun gets high. Spinner falls in late evening can be productive on cooler days.

Imitating patterns

Adult duns: Extended Body Green Drake, generic green/olive mayfly parachute dries (sizes 10–12), Purple Haze sized up. Emergers: Green Drake Sparkle Dun, Last Chance Cripple in olive. Nymphs: Pheasant Tail variants in size 10, Tung Jig Pheasant Tail in larger sizes, Frenchie in larger sizes.

References

• Wikipedia: Drunella grandis
• Mentioned in: 2026-04-26 - 2025 Blackfoot River Historical Analysis - Kingfisher (June reports)
• Field photo by Aiva Noringseth (CC-BY) via iNaturalist

Larva / nymph

Field photo (Kootenay Boundary, BC)