... it all depends on how hard-over you are in defining “Cowichan sweater”. These were produced by Salish (members of Cowichan Tribes) knitters in British Columbia commissioned by Filson. My particular model is one of 220 produced. They were hand knit from thick, hand-spun, one ply wool yarn. The pattern is traditional, with a single large salmon on the back, two smaller ones on the front, and repeating patterns (waves and leaves) on the body and sleeves. The colors are NOT purely traditional, because they used dyed blue and green yarn (rather than only natural shades of gray and cream). Close enough for me to call it Cowichan. Your mileage may vary.
Cheers,