Tennessee County High and Low Points
Using quick and dirty analysis with a 10M Digital Elevation Model (DEM), I produced this dataset which shows the high and low points for each county. The highest point in Tennessee (as any native would know) is in Sevier County at Clingmans Dome, at 6644.33' The lowest point is in Davidson County at a Vulcan Materials quarry at just 90.18' above sea level. Of course, this doesn't include locations that are underground, so let's qualify that this is the lowest point that is not underground. Below is the table if you want to look at your home county.