United States Government--postal Service, Postal And Zip Code Information 206 W 1st St Oshkosh, NE 69154 Phone : (308) 772-3551 Business Category Government Offices-Federal Social Service & Welfare Organizations Information & Referral Services Government Offices & Public Schools Post Office - Oshkosh 201 W 1st St Oshkosh, NE 69154 Phone : (308) 772-3551 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (308) 772-4586