Iowa Code Title XVI. Criminal Law and Procedure [Chs. 687-916] § 706.2. Locus of conspiracy

A person commits a conspiracy in any county where the person is physically present when the person makes such agreement or combination, and in any county where the person with whom the person makes such agreement or combination is physically present at such time, whether or not any of the other conspirators are also present in that county or in this state, and in any county in which any criminal act is done by any person pursuant to the conspiracy, whether or not the person is or has ever been present in such county; provided, that a person may not be prosecuted more than once for a conspiracy based on the same agreement or combination.