Ryan Brennecke / The BulletinFoisset’s Black TSW, courtesy Rainy’s Flies

“What do you call that fly?” the client asked. Fred Foisset, who owns Cascade Guides and Outfitters in Sunriver had been using the pattern for years. “I don’t know, but this sucker works,” he said. The name stuck. Ever since, this sparse leech pattern has been called Foisset’s TSW.

It really is a seal leech tied thin with a red bead. Instead of seal fur, the fly employs faux seal dubbing mixed with electric red fibers. Foisset likes to tie his wet flies without weight, preferring instead to use the line to take the fly down. Fish this one on a slow-sink line with a fluorocarbon leader and a 1-inch retrieve.

To tie Foisset’s Black TSW, start with a long wet fly hook. Slide a small red bead up against the eye. Use black marabou for the tail and a black/red Arizona Semi Seal dubbing. Finish with six wraps of a webby black soft hackle.

— Gary Lewis, for The Bulletin