The two PDFs at http://ioniacountyroads.org/projects.html have a map and details.

This bridge is being replaced, with the closure listed as being from 5/3 to 11/1. However, the barricades/detour block off over 5 miles of the road, due to being out in the country with many dirt roads.

I'm not sure how best to handle this. I assume marking just the bridge closed will end up routing people similar to the detour (3-4 miles south on Grand River) if they've got it set to avoid dirt roads. However, it may be confusing to have Waze's closure not match the actual barricade locations. On the other hand, blocking off that entire 5 miles creates a lot of opportunity for local traffic to drive on the "closed" road.