Steve,

In more recent years they started calling them "knobs," instead of "mounds." And there are a few of them, widely scattered across the landscape. You could find them across Sniabar Township and Washington Township in south Lafayette County and in north Johnson County. I think the ones you refer to are near Mayview, a few miles south of Lexington in Washington Township of Lafayette County.

You can pinpoint the ones you are seeking by referring to the Ramsay and Moser gazetteers of historical place names:

http://shs.umsystem.edu/manuscripts/ramsay/ramsay.html or http://thelibrary.org/lochist/moser/index.html

Bruce Nichols