There are some localized highway closures due to flooding. Here's a link to safetravelusa for South Dakota to check on your route. After you click on the link, scroll your mouse thumb wheel to maximize the size and drag the image using the left mouse button to center it.
Also, it's important to note that the flooded staging lanes did not come from the creek that runs through the track. Rather, it came across the road on the East side of the track. The race track itself received minimal rainfall and the pits are solid and dry.
https://www.safetravelusa.com/sd/