I made a graphic a long time ago sketching out the changes to IA 415 between Ankeny and Polk City, but I had based it on incomplete information. Once DOT route descriptions were released, Jason Hancock updated his listing, but I didn’t get to my page.
Now the IA 415 page has more details about how the highway changed, and when. The original alignment created from a piece of former IA 60 is now labeled as ca. 1970 instead of 1980.
I also have more photos for IA 210, including its former ends in Slater and Maxwell before extension in 1980.