In the early 1900s, archaeologist William Mills dug up a cache of carved stone smoking pipes that had been buried almost 2,000 years earlier. Mills was the first to dig the Native American site called Tremper Mound, in southern Ohio, USA. The pipes looked to have been carved from local stone, so he said they were. But Mills was wrong.
     The first researchers to actually test the pipes say most of the stone - and perhaps even the finished pipes - came from Illinois. They collected the mineral signatures of traditional pipestone quarries in Illinois, Kansas, Michigan, Minnesota, Missouri and Ohio, then compared the pipes from Tremper Mound. Of the 111 Tremper Mound pipes tested, less than 20 percent are local stone. About 65 percent are flint clay found only in northern Illinois, and 18 percent a stone called catlinite, from Minnesota.
     At Mound City - an elaborate cluster of immense mounds just 65 kilometres north of Tremper Mound, and inhabited at about the same time or shortly after - pipes are stylistically very similar, yet carved almost entirely from local stone.
     Thomas Emerson, principal investigator on the study and director of the Illinois State Archaeological Survey at the University of Illinois, says the Hopewell people who lived in the region from about 100 BCE to 400 CE have long been the subject of speculation, as the artefacts they left and the manner in which these were disposed of are not easily understood. Those in southeastern Ohio, especially, seemed to be "conspicuous consumers and connoisseurs of the exotic".
     They collected "massive assemblages of obsidian from Wyoming, mica from the Appalachian mountains, and caches of elaborately carved pipes," Emerson said. They also collected shells from the Gulf Coast (hundreds of kilometres to the south), along with the skulls of exotic animals such as an alligator.
     Emerson says most of the carved stone pipes from that era have been found in Ohio, where caches often containing more than 100 pipes were ritually broken, burned and buried.

Edited from e! Science News (18 December 2012)