[Jim McDougall]

David, thank you for posting this, which is really fascinating stuff toward the presence of metal edged weapons in the Northwest Indian culture which also includes the 'eskimo' tribal groups and others to the west. While not directly part of the Plains Indian subject, it is definitely pertinent as trade and influence had virtually no boundaries.

Most of what I have found pertaining to the metal used by these Northwest peoples from Tlingit to the broader Athapaskan groups as noted probably arrived on ship from either wrecks, or often trade vessels. By the late 18th century, the Europeans were aware of their having metal weapons, but as far as known all metalwork was 'cold worked'. Most smaller tools and knives were made from individual sections or pieces of metal termed 'toes', which were eagerly sought in trade.
The meteoric weapons which were apparently from an uncertain number of sources of meteoric iron, were cold worked by shaping and hammering with rocks it seems. The use of meteoric iron was well known among the Inuit and other aboriginal peoples.

I have not yet ever found a resource that mentions the smelting of iron or forging of blades among these peoples, nor of course with any of the American Plains Indians. The only forging of iron I have found was with the Koryak (perhaps via Evenk) far to the west across Bering Strait (with probable Chinese or Japanese influence, W. Fitzhugh, "Crossroads of Continents", p.231).

With the large size and broad shape of these Tlingit knife/swords it is tempting to associate them with the canoe paddles, which though of course wood, were similar in shape and used as weapons.