Iowa Code Annotated Chapter 724.4 Carrying Firearms
It appears you can carry openly outside city limits with no permit, and that carry of any sort inside city limits requires an Iowa permit (I don't know if Iowa has reciprocity, and I'm too lazy to go look it up for you, so i'll saw "iowa permit" to be on the safe side)1. Except as otherwise provided in this section, a person who
goes armed with a dangerous weapon concealed on or about the person,
or who, within the limits of any city, goes armed with a pistol or
revolver, or any loaded firearm of any kind, whether concealed or
not, or who knowingly carries or transports in a vehicle a pistol or
revolver, commits an aggravated misdemeanor.