According to the Iowa Secretary of State, you must generally drop your ballot off at your county auditor office (or at any satellite station that a county may set up) before it closes on the day BEFORE election day. Details on the location, operating hours, website, email address, and phone number for the auditor office in Calhoun County is as follows:
- 416 4th Street, Ste. 1 , Rockwell City IA 50579 (source)
- 8:30 AM – 4:30 PM, Monday – Friday
- Email: rbatz@calhouncountyiowa.com
- Website: www.calhouncountyiowa.com
- Phone: 712-297-7741