In June 1867, Thomas Francis Meagher, governing Montana Territory after his Civil War leadership of the famous Irish Brigade, rode to the Missouri River Port of Fort Benton to accept the transfer of guns and ammunition being shipped by steamboat from the U.S. arsenal at Saint Louis. At around 10 P.M. the night of July 1, he mysteriously disappeared from the decks of the steamboat G.A. Thompson. The mystery of his disappearance has eclipsed any effort to answer another question: What happened to the guns and ammunition? This non-fiction story pursues an answer, develops new facts and generates additional questions surrounding the more popularly known enduring mystery.