This bridge is a representative example of a grade separation project, where the railroad goes under the road.
Normally these types of structures would not be listed on this site. However, this structure has a high level of significance, and may have historically carried streetcars.
The bridge was built to serve as an improvement to 7th Street, which has to climb a massive hill out of Saint Paul.
The design chosen had to encompass the rail line below, as well as serve the traffic above. Construction would start 1883.
The design chosen was a two span stone arch (tunnel to the railroad). The arches were designed with a helicoidal design, meaning the stones are offset and skewed.
The Helicoidal design is exceptionally rare in the United States, and this is the only known one in Minnesota.
This was required because of the steel hill in which Seventh Street (MN-5) goes up. In addition, the structure was built with uneven sized arches.
Because of this design, this bridge is considered to be one of the most unique in the Twin Cities.
Today, the western arch carries the Bruce Vento Nature Trail, while the east is not in use.
The bridge is listed on both the National Register of Historic Places, as well as the American Historic Civil Engineering Landmarks. The bridge has been ranked as highly significant by the author, due to the design.
The photo above is an overview.