Looking at previous links to pictures, it appears that this possibly is an old railroad bridge. The previous flikr shot from below the Pratt span shows a stringer configuration typical of railroad bridges.
This is a three span Pratt through truss bridge with one regular (King?) and two Phoenix spans
Found some more pics:
non-Phoenix (King?):
https://www.flickr.com/photos/21953562@N07/5193365016/in/poo...
center span Phoenix:
https://www.flickr.com/photos/21953562@N07/5193353558/in/poo...
shot from below abutment on non-Phoenix span side:
https://www.flickr.com/photos/21953562@N07/5193344752/in/poo...
My guess would be that the King Bridge Co. built the newer span.
I agree Anthony. It has what appears to be Phoenix Columns and the details on the bridge are very Phoenix Bridge Co looking. I would assume this was fabricated by Phoenix Bridge Co and installed by King Bridge Co. Anyone know if this can be verified?
Very similar to the Tug Fork Bridge
http://bridgehunter.com/wv/mcdowell/24A240/
and obviously of earlier origin as well. Date may apply to the span that is mismatched with it.
https://bridgehunter.com/ky/greenup/hopewell/
This bridge looks very similar to the 1868 Hopewell Bridge (NR listed) in neighboring Greenup County.