Dark Cahill Quill
Dark Cahill Quill is a darker mayfly dry fly with a segmented quill body for trout feeding on dusky duns in cool clear water. It supports Dark Cahill Quill fly, dark mayfly dry, and trout hatch searches.
Imitates: Dark mayfly duns and cool-weather evening mayflies
Quick Reference
- Best Sizes
- #12-18
- Best Season
- Spring through summer
- Best Conditions
- Riffle tails, glides, and dim-light mayfly water
- Water Temp
- 50-64°F
- Recommended Tippet
- 5X-6X
How to Rig It
Fish it as a hatch-match dry when trout are taking darker mayflies off the film.
How to Present It
Present upstream with minimal drag and keep the fly riding flush but visible.
Why It Works
The dark quill body reads naturally to trout during subdued light and overcast mayfly windows.
History
Dark Cahill-style patterns hold a long place in classic dry-fly fishing where subtle body segmentation matters.
Pro Tip
This is a good swap when pale dries get refused and fish are eating slightly darker naturals.
Frequently Asked Questions
When should I fish Dark Cahill Quill?+
Use it during darker mayfly hatches in spring and summer, especially under softer light.
Not sure if Dark Cahill Quill is right today?
Get a fly recommendation based on live water temp, flow, sky, and time of day for any river in the US.
Open Fly Advisor
Map
Fly Guide