Overview
Slim emerger pattern developed by Rim Chung in the late 1970s, typically tied with a gray or olive thread/dubbed body, sparse microfibbet tail, and a small CDC or Antron wing. Its simplicity is key to its success in fooling selective trout. Often used in smaller sizes (#18-24) during BWO or midge hatches on tailwaters and spring creeks. The minimal materials create a delicate profile that sits naturally in the surface film.
Related patterns
Behavior & presentation
- Natural Behavior
- During emergence transitions, small mayflies and midges hang suspended just beneath the surface film as their bodies transform, wings partially unfolded and vulnerable. This transitional zone creates easy feeding opportunities for selective trout.
- Where Trout Eat It
- Fish suspend just below the film in smooth water, slicks, and tail-outs at depths of 6-18 inches during hatch activity.
- How to Fish It
- Dead drift in or just below the film, maintaining natural speed without drag or unnatural movement.
- Best Water
- Target slicks, tail-outs, back eddies, and seams at spring creek margins and tailwater runs where emergers concentrate.
- Strike Type
- Watch for subtle sips, indicator hesitations, or barely perceptible film movements as fish take gently.
Fishing strategy
- Rigging Suggestions
- Try it as the top fly in a tandem nymph rig or on a dropper 18-24 inches off a dry fly. Use 5X-6X fluorocarbon tippet for delicate presentation.
- Seasonal Timing
- Most productive March-May and September-November during periods when midges and small mayflies are hatching. Water temperatures between 45-65°F are ideal.
- Pro Tips
- This fly is designed to sink to imitate an emerging insect. The CDC wing adds some movement and visibility, but it is a subtle pattern designed to fool wary fish in clear water.
Where to fish it
Rivers anglers pair with this fly, with local shops that stock it.
River details and fly shops from River & Run, our sister site.
Entomology
Small mayflies and midges drift in the transitional zone just below the water's surface as they prepare for emergence, their wing cases darkening and bodies beginning to shed their nymphal shucks. Fish position themselves in feeding lanes to intercept these ascending insects, which represent an easy target during the vulnerable transformation from aquatic to terrestrial life stage.
- Order
- Ephemeroptera
- Common name
- Mayfly
- Organism
- insect
- Life stage
- general
Pattern details
- Stillwater
- Moving Water
- Rocky Mountain
- Worldwide
- classic
- guide-fly
- dead-drift
- dry-dropper
- beginner-friendly
- baetis-hatch
- midge-hatch
- tailwater
- spring-creek
- low-clear-water
