Background and Schedule

Thank you for visiting the project website for the "Interchange and Environmental Study for I-229 Exits 3 and 4". These two studies, one for each exit, are analyzing alternatives developed in the previous I-229 Corridor Major Investment Study (MIS) and developing a preferred concept for each exit. Both studies will also include environmental review and documentation.

Please check back periodically for additional project updates, or sign up for project updates and meeting notifications.


For additional information on the previous "Major Investment Corridor Study", visit the website at

You may also visit the South Dakota Department of Transportation website at