Since its discovery in 1887, controversy over the authenticity of the Thoen Stone has circulated. Many people believe that the stone is a
hoax and was fabricated by Louis and Ivan Thoen. Some have pointed to the fact that Louis Thoen was a
stonemason.
Thomson investigation In the 1950s, Thomson traveled to the
East Coast in search of the families of the party's members. Thomson located several families, all with surnames similar to those listed on the Thoen Stone, who claimed to have had ancestors who disappeared in the
American West around 1830. Some of these relatives had written back to their families before their disappearances. One, Kent, allegedly had sent a letter—possibly using one of the
American Fur Company trading posts in the territory—reporting that he had found gold and would be returning home. Thompson also found evidence that Brown grew up in North Carolina during a local gold rush and may have gained knowledge of
placer mining techniques during that time. Additionally, King and Indian Crow were both from
Lumpkin County, Georgia, where another local gold rush took place in the 1820s. Thomson found that Kind himself was a German immigrant to Pennsylvania, and that he had indeed left home to travel west in the 1830s and disappeared. Thomson theorized that the attack on the party may have been orchestrated by the American Fur Company as a way to dissuade outside encroachment in its territory, and found evidence that the company had indeed sponsored attacks on other parties from its positions at
Fort Pierre Chouteau and
Fort Clark. Thomson also believed that the hunting knives carried by pioneers in the 1830s would have been sturdy enough to inscribe a message in a wet sandstone slab, and theorized that Kind would have had ample time while hiding to carve something.
Modern investigations In the 2000s, handwriting expert Marion Briggs and another in California compared the handwriting on the postcards and the writing on the slab. Both determined that the inscriptions were not done by the same person, and the stone was not inscribed by either of the two Thoen brothers, Cashner, or John S. McClintock, who was an early advocate for the slab's authenticity. ==In popular culture==