According to OpenCarry.org with regard to Iowa
http://www.opencarry.org/ia.html
http://www.opencarry.org/ia.html
Iowa is not a traditional open carry state, but no permit is required to open carry except when in vehicles or when inside city limits. Open carry in cities is technically legal with an Iowa permit to carry weapons, however Iowa is a may-issue state, and some sheriffs have indicated that they will revoke your permit for open carrying.