Of 102 counties in the Inland Empire, Mercer County ranks 44th in terms of size (568 square miles). Mercer County is in Western Illinois. There is around 1,000 acres of ranches for sale in Illinois's Mercer County based on recent Land Network data. The combined market value of farms, hunting land and other rural land and acreage for sale here is nearly $500,000. Browse all Mercer County ranches for sale on the Land Network to find the ranch that's right for your business or commercial needs, from the sprawling legacy ranch to unbelievable residential ranch for your second home, investment property or retirement nest egg. The most common type of land for sale by combined acreage in Mercer County is farms.