Post Office - Sloan 309 4th St Sloan, IA 51055 Phone : (712) 428-6225 Business Category Post Offices Toll-Free           (800) ASK-USPS United States Postal Service , Phone : (712) 428-6225 United States Postal Service Business Category United States Government--for Zip Code Information Sloan, IA 51055 Phone : (712) 428-6225 Business Category Government Offices-Federal Social Service & Welfare Organizations Information & Referral Services Government Offices & Public Schools