Spencer, IA Plant Spencer Plant | Office 225 W 21st St Spencer, IA 51301 +1 712-262-1366 Mailing Address: PO Box 1220 Spencer, IA 51301-1220 Office Hours: 7:00 AM to 5:00 PM Monday thru Friday Plant Hours: 6:30 AM to 5:30 PM Monday thru Friday Contact Us Calculate population in area Thank You for Your Interest in Our Company. Quality in Everything We Do!