The Tlingit artist Tommy Joseph has replicated a traditional set of armour:
… body armor made of alder slats and rods and woven together with hemp. Wooden panels are stitched together with leather lacing. Moosehide straps. Two alder toggles fasten the armor around the body.
It’s for sale: $3,500.
I was looking into this because of a recent post on Linen Armour (!) at Heather Pringle’s blog — I tried to leave a comment there in response to a question about NW Coast armour but wordpress ate it — probably because I had a bunch of links. Dan form there, if you read this, most likely the armour Simon Fraser saw was made of two or more layers of stiffened elk hide.