Stimulator
The Stimulator is the big bushy attractor that plays adult stonefly, hopper and skater at once - and floats so well it carries a nymph dropper like a pack mule.
Randall Kaufmann's Stimulator is the western box's big orange workhorse: a palmered, elk-winged cigar that suggests golden stones, salmonflies, caddis and hoppers in one buggy mouthful. It floats like a cork through canyon water - which is why half its working life is spent as the indicator fly hauling a beadhead beneath it.
What it imitates
Adult stoneflies first (goldens and salmonflies), plus general 'big bug': hopper-ish, caddis-ish, protein-ish.
When & where it wins
Stonefly hatches on western rivers (the June salmonfly circus especially), summer canyon water, and year-round as the buoyant top of dry-dropper rigs.
How to fish it
Bang the banks and seams dead-drift; twitch-skate at dusk for caddis energy. Dry-dropper: 60-120 cm of tippet off the bend to a tungsten nymph - the Stimi never sinks.
Sizes & variants
8-16, orange/yellow/olive; the Chubby Chernobyl has stolen some of its indicator work with foam, but the Stimulator still looks more like food.
Tying notes
Palmered hackle over dubbing, elk wing, hackled thorax - a stamina tie with cheap materials; crowd the eye and it's ruined (the classic error).
Common mistakes
Too-light droppers twisting the leader (keep nymphs proportional), ignoring the twitch, and fishing it undersized during actual salmonfly season - go BIG when the naturals are 5 cm.