The pack may not look like much, but it has an interesting history, hence the $100,000 price tag. Hopefully it'll go to a good home, a museum perhaps. Some info from the seller.
Up for auction is the holy grail of camping/ hiking equipment in this patented in 1882 Duluth "Poirier Pack Sack" Backpack Rucksack Bag. (Actual Date on this Camille Poirier Strap Pack is "PAT'D NOV. 10. 1882.") The application for the "Pack Strap" at the US Patent Office was filed on October 11, 1882. Handmade in Duluth, Minnesota by Camille Poirier himself, who pioneered the company (today known as Duluth Pack, Duluth-MN).
October 11, 1882 - Camille Poirier, himself applied/filed for the patent.
November 10, 1882 - On the metal plate on this Prototype Strap Pack, in this auction.
December 12, 1882 - Actual Letter of Official Patent.
More info on the history of Duluth Packs can be read here. Also, Lesli Larson's wonderfully distracting blog, ArchivalClothing.com, has some great posts about canvas canoe packs as well.
Dec 2013 UPDATE: The working theory is that this is a prototype pack made by Camile Poirier himself before his patent was granted on Dec 12th, 1882. The oxidized copper plate is marked with the date of Nov 10, 1882 somehow making this specific pack special. I did some digging however and found that all Poirier packs have the metal plate stamped with the date of Nov 10, 1882 and were made until 1911 when Poirier sold the company to Duluth Tent and Awning (i.e. Duluth Pack today). Here's another example in better condition with the same metal plate:
Photo Credits: Wary Meyers