In looking closer at the pictures of this bridge I noticed an identical feature in this bridge to the Hamilton Road Bridge in Allen Co., IN. The ends of the floor beams feature a design that tells me this is a Smith Bridge Co. span. That would also date this bridge to the 1880's, since Smith Bridge became the Toledo Bridge Co. around 1890.
These pictures show the floor beam end and the portal details on the Hamilton Road Bridge.
Webmaster's note: The photos that were here have been incorporated into the main site.