The Portage High Bridge in the park was originally constructed in 1875 as a replacement of the famous wooden bridge that burned in May of that year. Heavy railroad use of the bridge and the constant spray from the River necessitated repairs and upgrades over the years. The first major project was in 1903. The engineering drawing found below shows the extent of that work which included the replacement of much of the original deck with single-track girders. For an eyewitness description of the work click here.

The diagram is from Henry G Tyrrell's "History of Bridge Engineering" (Chicago, 1911). We thank our friend Jim Stewart for sending it to us.