What is the best way to check the correct shape? way/58647281 of relation/129130 has source: 'TIGER/Line® 2008', way/15807731 of parent administrative element has no source. For the curiosity I have checked shape files of state boundaries from https://clearinghouse.isgs.illinois.edu and https://geodata.iowa.gov/ - neither matches OSM ways  nor do they match each other.