Letterbox is not at the posted coordinates.
Welcome to the “Puzzling, Ain’t It?” letterbox geo-art! We created this Geo-Art as a way to help others finish their letterbox fizzy! Almost all of the D/Ts in this series are ones that are not in Iowa for letterboxes at the time of this publishing. These are mystery-style letterboxes.
You can validate your puzzle solution with
certitude.
(Puzzle by 57Orion)