While there are no secret patterns that are guaranteed to catch fish every time you are on the water, the closest thing to it would be the Pheasant Tail Nymph. This generalist nymph pattern is close enough in color to a host of invertebrate species that - when fished in a number of sizes - can be used to effectively imitate almost any mayfly or stonefly nymph in the water. This traditional tie is done without a flashback or beadhead to provide a light drift and realistic coloration so as not to spook selective trout.
Fly Category: Generalist Pattern
Family: Mayflies, Stoneflies
Species: Blue Quill, Blue Winged Olive, Brown Drake, Brown Dun, Caenidae (Angler's Curse), Grey Drake, Hendrickson, Mahogany Dun, March Brown, Red Quill, Slate Drake, Trico, Western Green Drake, Skwala, Golden Stonefly, Early Brown Stonefly, Chloroperlidae, Winter Black Stoneflies
Life Stage: Nymph
We fly fish the John Day River in Oregon at least a couple times each summer for smallmouth bass. Most fisherman on the John Day are throwing large rubber things or things with propellers. The Pheasant Tail Nymph has been one of my go to flies for years. You can fish water right behind one of the other boats and pick up fish that had been pounded by spinning gear.