Let me know if you have seen this one.    I was boating on the Iowa River South of the Hwy 92 Iowa River Bridge and saw this bridge under the Railroad bed South of Columbus Junction.  The Arch caught my eye.

The bridge is 3.5 miles South of the Hwy 92 Iowa River Bridge.  The star marks the spot at Lat./Long  41.2485  ,-91.2929 in the Google map below.