Called it: Missouri River bridge daunting for engineers

In South Dakota infrastructure suffers to prop up the state's retirement system so, at a price of some $50 million+ (much of it federal dollars) the red moocher state chose an Iowa builder to replace the bridge across the Missouri River between Fort Pierre and the cesspool on the east side. Built in 1962, it was deemed in 2016 that the existing span is structurally deficient and functionally obsolete. 

In 2020 South Dakota was 4th in the US in the number of structurally deficient bridges at 17 percent and 10th in the percentage of structurally deficient bridge deck area.

In 2021 this blog said the bridge might open in 2023.

Dean VanDeWiele is a South Dakota Department of Transportation Pierre-area engineer. “You're just seeing the river water elevation, and so when you're going down you really had to watch the evaluations of your auger as your drilling because you never really know if you got a good bite of clay as you're pulling it up... Or did you not get any clay at all, did you go too deep, and it's very hard for the crane to lift back up?," said VanDeWiele. The Department of Transportation said the new bridge is anticipated to be open for traffic usage in the summer of 2024 with an anticipated completion date of the summer of 2025. [Bill Janklow's idea of public radio]

But here’s the dealio. In 2011 an earthquake that occurred ten miles under the clay sinkholes that developed in the Pierre Shale in Stanley County was large enough to be felt by humans who live there.

The Cretaceous shale between Oacoma and Rapid City or between Fort Pierre and Rapid City is a major obstacle and is one reason passenger rail across South Dakota failed but two east/west rail routes across South Dakota exclusively for freight is lunacy. 

So, if an existing track bed between Oacoma and Rapid City can be salvaged and made good enough for passenger rail it admits the geology is stable enough for a tar sands pipeline.