 Story County is the home of the Iowa Department of Transportation and the location where the historic Lincoln Highway and I-35 intersect.The first section of I-35, a stretch from Cumming to Urbandale opened around September 21, 1958.Within five years, the interstate had grown to , extending from U.S. Route 34 (US 34) Osceola to the eastern interchange with I-80 and I-235.