I found the shell casing in the image below while digging through a historical site in the Owens Valley Desert, on the eastern edge of the Sierra Nevadas and Mt Whitney in North America.

Can anyone help me determine the decade it may have been manufactured?

That headstamp was in use for a long time. It came into use in the mid-1930s and was in use well into the 1960s. This picture I have already loaded in Photobucket is of 10-gauge shells. Left to right -- late 1920s early 1930s - mid-1930s thru WW-II - Post WW-II --



Is the case body cardboard or plastic? If it is cardboard, is any of the Western and Super-X markings still visible on the sides of the tube? Again 10-gauge shells, center being the pre-WW-II markings and right post WW-II markings --



Also, if a cardboard tube can you tell if it was roll-crimped or had a pie crimp? The Western Cartridge Co. 20-gauge Super-X loads got what Western called the Super-Seal crimp in 1948. If plastic, is it a plastic tube with a fiber base wad or is it compression formed plastic?

It looks like the sides were crimped for plastic after the war, if I'm not mistaken.



And, is that a fiber base wad?

The only training with firearms I've ever had was with a BB gun in the Boy Scouts. So--I'll have to leave even the obvious to the experts.

Thank you for all your help.

Yes. Somewhere between 1946 and 1962, by the canular rings in the brass. That is a fiber base wad. Can't really tell whether the shell had a cardboard or an early style plastic tube (from the early 1960s), as the canular rings in the brass were the same for both.

I found the shell a little bit south and west of the location of the flagpole in this old photo of the Manzanar relocation center in Owens Valley, California:


Based on the above, the shell was most likely spent sometime after the camp closed. It was ordered closed by the government November 21, 1945, and took two years for all of the internees to relocate and most of the structures to be removed.

There were some forced evacuations: most of the people there had nothing left after the war and had nowhere to go. ( Maybe it's little surprise that the government didn't really give the people there enough money to relocate and have enough money to survive the year? ) So, a few families were removed by force.

Nonetheless, the entire story of internment at Manzanar only accounts for two of the sixteen years that shell was manufactured. So, just probabilistically speaking, the shell very likely didn't come from the forced relocations.

During the other 14 years, the site was used as a veteran's hall and road maintenance shed. The surrounding county has always had some local presence as well. The field to the south had several, spent shotgun shells from post 2005, for example.

Thank you again! Best regards.