Cowry
The Ojibway aboriginal people in North America used the cowry shells in ceremonies, and the Whiteshell Provincial Park in Manitoba, Canada is named after this type of shell.  There is some debate about how they traded for or found these shells so far inland, away from the natural sources.  Oral stories and birch bark scrolls seem to indicate that they were found in the ground, and/or washed up on the shores of lakes or rivers.  The cowry shells so far inland may indicate the use of them by an earlier tribe or group in the area, and an extensive trade network in the ancient past.