Town Hall Address 1100 Main St Mount Vernon, IL 62864 United States- Jefferson County Website http://www.mtvernon.com/ Zoning (618) 242-5000 1100 Main St Mount Vernon, IL 62864 United States Fire District (618) 242-6880 714 S 42nd St Mount Vernon, IL 62864 United States Town Clerk (618) 242-5000 1100 Main St Mount Vernon, IL 62864 United States Tax Collector 618-244-8016 7 100 S. 10th Street Mt. Vernon, IL 62864 United States County Jefferson