The comment above or below was me!
This was a neat example of an early state highway Parker truss on a decomissioned state highway. US 421 was shifted over to I-74 upon completion in the 60s, and the county took over the road and bridge and I'd say not maintaining well. The weight limit went down to two tons all of a sudden and the bridge was shut down after numerous semis were spotted crossing. Afterwards the county just threw it away! By the way thanks for adding the photo Tony!