| Name | High Trestle Trail - Big Creek Bridge Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge #Z-1116 |
| Built By | Chicago, Milwaukee & St. Paul Railway |
| Currently Owned By | Boone County Conservation Board |
| Superstructure Contractor | Unknown |
| Substructure Builder | Chicago, Milwaukee & St. Paul Railway Company Forces |
| Length | 65 Feet Total |
| Width | 1 Track, Formerly 2 Tracks |
| Height Above Ground | 10 Feet (Estimated) |
| Superstructure Design | Deck Plate Girder |
| Substructure Design | Concrete |
| Date Built | 1912 |
| Traffic Count | 0 Trains/Day (Bridge is Open to Pedestrian Traffic) |
| Current Status | Open to Pedestrian Traffic |
| Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge Number | Z-1116 |
| Significance | Local Significance |
| Documentation Date | 10/21/2018 |
In 1870, the Sabula, Ackley & Dakota Rail Road (SA&D) constructed a 21-mile railroad line, extending from the Mississippi River at Sabula, Iowa to Preston, Iowa. The following year, an additional 12 miles were completed to Delmar, Iowa. In 1872, an additional 54 miles were completed to Marion, Iowa. In 1872, the SA&D was conveyed to the Milwaukee & St. Paul Railway (M&StP), which reorganized as the Chicago, Milwaukee & St. Paul Railway (Milwaukee Road) in 1874. In 1882, the Milwaukee Road completed an additional 257 miles between Marion and Council Bluffs, Iowa; completing a mainline from the Mississippi River to the Missouri River. The same year, a bridge across the Mississippi River was completed at Sabula, which connected to the existing Milwaukee Road system in Illinois. By the late 19th Century, the Milwaukee Road had developed a large railroad network throughout the Midwest. This line quickly became a principal mainline for the Milwaukee Road, and allowed for the connection and construction of other branch lines throughout Iowa.
In 1901, a short 12-mile cutoff was completed between Green Island, Iowa and Browns Junction, Iowa; which shortened the distance and provided better grades. The original line was retained as a second track. In the early 20th Century, the Milwaukee Road was aware of the importance of this line, and a massive construction project was planned to modernize the line. Between 1912 and 1915, the line between Green Island and Manilla, Iowa was extensively rebuilt, with a second track constructed and large sections of line relocated. The result was one of the most modern double track lines in Iowa, complete with smooth curves, gentle grades and new bridges. After completion of the project, some short sections of the original line were retained as spurs, which were abandoned by the early 1920s. The Milwaukee Road failed to accurately project the level of traffic over this line, and traffic never reached the threshold that required a double track line. The Milwaukee Road was often in financial trouble, especially after the costly Pacific Extension was completed in 1909. In 1925, the company declared bankruptcy, and reorganized as the Chicago, Milwaukee, St. Paul and Pacific Railroad in 1928. Despite the financial strain, this line remained an important mainline for the Milwaukee Road. Segments between Marion and Covington, Iowa; Newhall, Iowa and Collins, Iowa; and Madrid, Iowa and Templeton, Iowa were reduced to a single track in 1934. The segment between Green Island and Paralta, Iowa was reduced to a single track in 1950; the segment between Paralta and Marion in 1954; the segment between Collins and Madrid, Iowa in 1956 and the segment between Covington and Newhall in 1964. In addition, the original line east of Browns Junction was abandoned in 1950. Financial hardship continued through the 20th Century for the Milwaukee Road, and the railroad again filed bankruptcy in 1977. In 1980, the Milwaukee Road decided to abandon the entire Iowa Division mainline. The segment between Bayard, Iowa and Council Bluffs was sold to Burlington Northern Railroad (BN). Segments between Perry, Iowa and Bayard and between Slater, Iowa and Woodward were sold to the Chicago & North Western Railway (C&NW). A short segment at Marion was sold to the Chicago Central & Pacific Railroad (CC).
In 1985, the segment between Herndon and Bayard was abandoned by the C&NW. In 1995, the C&NW was purchased by Union Pacific Railroad (UP). In 1996, BN merged with the Atchison, Topeka & Santa Fe Railway to form BNSF Railway. The CC was purchased by Illinois Central Railroad (IC) in 1996, and the IC was purchased by Canadian National Railway (CN) in 1998. In 1999, the segment between Dawson, Iowa and Herndon was abandoned by UP. In 2002, most of the segment at Marion was abandoned by CN. Between 2003 and 2004, the remaining portions between Slater and Woodward and between Perry and Dawson were abandoned by UP. Today, BNSF operates the Bayard to Council Bluffs segment as the Bayard Subdivision, and CN still operates a short segment of line in Hiawatha. Linn County has developed large sections around Marion into the Grant Wood Trail. A section west of Rhodes, Iowa has been reused as a trail; and segments between Collins and Slater have been reused as the Heart of Iowa Nature Trail. Much of the line between Slater and Perry has been reused as the High Trestle Trail; and the line between Perry and Herndon has been reused as the Raccoon River Valley Trail. Remaining segments have been abandoned, with much of the right-of-way still intact. In addition, large segments of the original right-of-way that was replaced in the early 20th Century remain intact.
View historic articles discussing the double tracking of this line (digitized by Google)
Located between Slater and Madrid, this deck plate girder bridge carries a former Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road) mainline over Big Creek. The first bridge at this location likely consisted of a timber pile trestle, constructed when the line was first built. In 1905, the timber bridge was replaced by a 65-foot deck plate girder span, set onto new concrete abutments. Between 1912 and 1915, the Milwaukee Road reconstructed the mainline across Iowa, improving the alignment and grades, constructing new bridges and adding a second track. In 1912, a new double track bridge was constructed slightly north of the 1905 structure, reusing the 1905 span for the south track and installing a new deck girder span for the north track. The bridge remained double tracked until 1956, when the south track was removed. The south track span remained intact until at least 1958, and it was likely removed in the late 1950s or early 1960s, giving the bridge its present configuration. It is unclear if the south track span was reused or scrapped, although it is is known spans from the second track of this line were reused in Washington State.
Currently, the bridge consists of a single track 65-foot deck plate girder span, set onto concrete abutments constructed for two tracks. In addition, the abutments of the 1905-era alignment are visible immediately to the south of the bridge. Originally, the bridge used a concrete ballast deck, which used precast ballast channels placed on top of the girders. This ballast deck was apparently removed immediately prior to the bridge being converted to trail use. The superstructure follows a standard design, with two heavy plate girders. The abutments also use a standard design, with sloped wing walls and timber pile foundations. An unknown contractor fabricated the superstructure, and an additional unknown contractor fabricated the south track span, which was removed in the 1950s or 1960s. Typical of Milwaukee Road concrete structures in the early 20th Century, the abutments were constructed by labor employed by the Milwaukee Road Bridge & Building Department. Deck plate girder spans were popular for railroad use, as they were durable and easy to construct. In the mid-2000s, the original concrete ballast deck was removed, and a new concrete deck on timber blocking installed. Aside from this, the bridge has seen no significant alterations. Today, the bridge is used by the High Trestle Trail, a popular trail in Central Iowa. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked the bridge as being locally significant, due to the common design.
Citations
| Build date | Milwaukee Road Bridge Index, located at the Milwaukee Road Archives at the Milwaukee Public Library |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |