Post Office - Davis Junction 402 W Chicago Ave Davis Junction, IL 61020 Phone : (815) 645-8116 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (815) 645-8539 United States Govt 402 W Chicago Ave Davis Junction, IL 61020 Phone : (815) 645-8116 Business Category Government Offices-Federal Government Offices & Public Schools