All Illinois county highpoints were completed simultaneously on July 30, 2003
by Dick Ellsworth, Jon Mann, John Mitchler, and Tim Worth at Calhoun County.
Bob Schwab completed later that year. Another source of information for Illinois county highpoints
AND lowpoints is provided by the Illinois State Geologic Survey. Trip Report Compendium - by John Mitchler and updated (twice) by Tim Worth.
This document is large (beware of download time) and contains some information
that is already available as individual trip reports or as first ascents information.
Nevertheless it is essential material for Illinois county highpointing. Annotated Map - by John Mitchler.