Interstate 35 in Iowa

Interstate 35
I-35 highlighted in red
Route information
Maintained by Iowa DOT
Length	219.225 mi[1] (352.808 km)
Existed	ca. September 21, 1958[2]–present
History	Under construction 1958–1975
NHS	Entire route
Major junctions
South end	I-35 near Lamoni, Iowa
Major intersections	US 34 at Osceola Iowa 5 at West Des Moines I-80 / I-235 near Des Moines US 30 at Ames US 20 near Williams US 18 / Iowa 27 near Clear Lake
North end	I-35 towards Minneapolis-St. Paul
Location
Country	United States
State	Iowa
Counties	Decatur Clarke Warren Polk Story Hamilton Wright Franklin Cerro Gordo Worth
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Iowa Primary Highway System Interstate US State Secondary Scenic
← US 34 → Iowa 37

Interstate 35 (I-35) is a north–south Interstate Highway in the United States that runs from Laredo, Texas, to Duluth, Minnesota. In Iowa, the highway runs from south to north through the center of the state, roughly parallel to U.S. Highway 69 (US 69) and US 65. It enters the state near Lamoni from Missouri and continues north through the southern Iowa drift plain. In the Des Moines area, I-35 runs concurrently with I-80, and the two highways bypass Des Moines to the west and north. I-235, the only auxiliary route of I-35 in the state, serves the suburbs and downtown Des Moines; it begins and ends at the two interchanges where I-35 and I-80 meet. Near Mason City and Clear Lake, US 18 and Iowa Highway 27 (Iowa 27) overlap with I-35. Shortly after, US 18 splits off to the west in Clear Lake, while Iowa 27 runs with I-35 until they reach the Minnesota state line.

Construction of I-35 in Iowa took place over 17 years. The first 10-mile-long (16 km) section of the route that stretched from Cumming to Urbandale was opened on September 21, 1958. In the next 14 years, new sections of the route opened regularly, only leaving the section between Mason City and US 20 incomplete. On November 14, 1975, the last 50-mile-long (80 km) section of the route was completed and connected the two noncontiguous sections of I-35.