During the bolshevik revolution, the first Bn 339th Inf from michigan was sent to join the fight in siberia. When the russians and americans retreated, they were forced to leave behind their dead and wounded. In the early 80's a group led a covert operation into siberia to recover the american soldiers remains left on the battlefield. Reports from that operation state that the battlefield had changed very little, in fact the bodies were perfectly preserved and the trenches were still intact. The 1st Bn 339th IN were known as the polar bears. The remains of19 soldiers were recovered but the operation was compromised and was forced to terminate leaving the remainder of the 38 in siberia. Those recovered are buried around the polar bear monument at white chapel cemetery in troy, mi. I believe you found a button from one of their coats probably lost during training at somepoint around 1911