An ancient piece of pottery was dropped off at a Goodwill thrift store by an unknown donor in New York State. A note inside identified the piece as originating with the Caddo Indian Nation, whose traditional grounds include parts of Oklahoma. The pottery will now be returned to the Caddo American Indians, according to the Associated Press.

The piece, a fluted and unglazed vessel measuring just under eight inches tall, had been put up for auction and might have sold for under $5, judging by the two bids it received. But potential buyers soon noticed the text of a note that had been tucked inside the piece. It read: Found in a burial mound near Spiro Oklahoma in 1970.

The Spiro Mounds site is seven miles outside of the town of Spiro, Oklahoma. According to the Oklahoma Historical Society, it is the only prehistoric, Native American archaeological site in Oklahoma open to the public. The mounds are one of the most important Native American sites in the nation ... Artifacts indicate an extensive trade network, a highly developed religious center, and a political system, which controlled the entire region.

There were inhabitants in that area during prehistoric times, according the historical society. Although various groups of people camped on or near the Spiro area over the previous 8,000 years, the location did not become a permanent settlement until A.D. 800 and was used until about A.D. 1450.

If the vessel found at Goodwill hearkens back to those times, this rare find could be a legitimately prehistoric artifact. As of yet, however, it's hard for experts to tell when exactly this mysterious vessel was created.

When the object was first displayed for online auction at shopgoodwill.com, along with a transcription of the note found inside, Web surfers emailed Dan Victori, the e-commerce manager. People recognized it right away, said Victori to Buffalo News. We had no idea what it was.

Jeremy Juhasz, a website coordinator for Goodwill, expressed surprise over the rare find. We're pretty amazed the thing wasn't (a) broken or (b) just thrown out, he said.

Goodwill staffers reached out to Oklahoma officials, eventually getting in touch with members of the Caddo Indian Nation. The tribe decided to reclaim the possibly prehistoric artifact, and Goodwill agreed to hand over the piece rather than auction it off for a profit.

Once we were alerted to what it was, there was no doubt that we were happy to donate it back to them, said Jurhasz.