Mercer County is in the top 20 when it comes to the Illinois’ healthiest counties. Mercer County is ranked 15th out of 102 Illinois counties in a report released by the Robert Wood Foundation at the University of Wisconsin. The rankings point to a number of factors, like health behaviors, education, socio-economic status, access to health providers, and housing quality. Woodford County comes in as the healthiest in Illinois. Alexander County is southern Illinois comes in last.