Photo taken by Daniel Barnes in April 2017
BH Photo #387807
Wow! A ceramic builder plaque! Great Find! I normally only ever see those in Canada (not sure why several builders in Canada used them), where they are extremely rare. Even more rare in the states.
I've seen a couple of spans along this line with the same Wisconsin Bridge & Iron Company tag as Daniel found in photo 12, most notably one in adjacent Story County:
I've speculated before that they likely did a rehabilitation within the last 50 years, and left the tag. It seems to me that if they actually built the structure, they would have left a plaque instead. The Ames bridge has a Lassig Bridge & Iron Works plaque, the true builder of at least that span. I would suspect this span dates to a similar time frame, when the route was double tracked. According to a Union Pacific chart, this route was double tracked at this location between 1901 and 1902.