They did not have information about the burial location, because the family did not disclose it to outsiders.

The historical record from the late 1870s and early 1880s contains references to the burial mystery in the form of people noting that the location was unknown.

This is itself historically significant: the uncertainty was documented from almost immediately after his death.

The only sources with any claim to specific knowledge about the burial location are the oral accounts of Lakota people whose family connections might have given them access to the information the family kept.

These accounts — by their nature — are filtered through memory, are selectively shared, and are not confirmed by physical evidence.