During my lecture tour in 2012 in Wisconsin and Minnesota, I found accommodation in the home of good friends - the family Rusterholz - in River Falls. Although River Falls is not known as a centre for agate finds however the Rusterholz family succeeded in finding a small Lake Superior agate in their garden.

On excursions in the vicinity, we found mainly gravel of fossil rich ordovician sediments (stromatolithe, coral), which were here transboundary spent by glacial streams that are not affecting the original occurrence of the Lake Superior agates. Between these Cobbles agates of the CWOA type (Central Wisconsin oolithic agate) were found again and again.