Skunk - NW Steelhead fly Icon. There well have been more summer Steelhead caught on a Skunk, or Green Butted Skunk fly pattern that any other single pattern around. A must in every Steelhead Fly Fishermen's Fly box. The origin of the traditional Skunk pattern, as with many other steelhead flies, will remain a mystery forever. Many believe it originated about 70 years ago in southern Oregon's North Umpqua, or by Wes Drain of Seattle for the Stillaguamish River in Washington.