about twenty years ago digger and I found a two and one half gallon indian pickle pail
never did get it all put together still got the pieces laying back in the shed in a few boxes
the diameter of the top rim of that one matched the radius of a plastic 5 gal bucket
many of those pots were for storing corn, dried squash, pemmican,and mussel shells for future use as trade commodities...........when i talked with the ND state historical society rangers and guides, i was told just what i had already re-affirmed.... the mandan-arikara-hidatsa bands had so much food stored that they were able to use it for trade items and it would never cut them short since they had years worth stored on site in cache pits
then one time we saw a couple huge pieces of pottery in a washout gully, when we looked we found these huge
pieces of a busted pot that looked like it was packed with mussel shell
they were scattered and disturbed but there was enough to see that they were nested one on top of another...and...which appeared to have been in an orderly manner to save space