U S Government--post Offices, Forreston Forreston, IL 61030 Phone : (815) 938-2161 Business Category Post Offices Government Offices & Public Schools Post Office - Forreston 210 E Main St Forreston, IL 61030 Phone : (815) 938-2161 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (815) 938-3563