Totally agree with you Nathan. I was just looking at some Milwaukee B&I spans and feel like it could definitely be a product of theirs.
I strongly agree, given its unusual vertical members and its location in Wisconsin, I suspect it to be an 1870s product of Milwaukee Bridge and Iron Works see interior verticals here: http://bridgehunter.com/wi/racine/bieneman/ or diagonals here: https://historicbridges.org/bridges/browser/?bridgebrowser=t...
Interesting arched portals and v-laced endposts on this one. 1870's perhaps?
Definitely looks like the same style of v-lacing as the Bieneman Bridge.