I-35

About I-35

Also known as Purple Heart Trail.

From Laredo, TX (Mexico border) to Duluth, MN (I-535)

Interstate 35 is a major north-south route of about 1,568 miles running from Laredo, Texas, on the Mexican border to Duluth, Minnesota, on Lake Superior. It crosses Texas, Oklahoma, Kansas, Missouri, Iowa, and Minnesota, forming a central spine of the national grid and a primary trade corridor between Mexico and the upper Midwest. The route splits into lettered branches through two large metropolitan areas.

From the border at Laredo the route runs north through San Antonio and Austin, then splits into I-35E through Dallas and I-35W through Fort Worth before rejoining north of the metroplex. It continues through Oklahoma City, Wichita, Kansas City, and Des Moines, then splits again into I-35E and I-35W through the Twin Cities of Minneapolis and Saint Paul before ending at Duluth.

The corridor carries heavy international freight tied to trade with Mexico, especially through the Laredo gateway, and serves a string of fast-growing cities in Texas and the Great Plains. It is one of the few mainline Interstates with two separate lettered splits along its length.

State-by-state mileage

State	Miles
Texas	407.2
Oklahoma	235.9
Kansas	235.5
Missouri	114.7
Iowa	218.4
Minnesota	259.6
Total	1,471.3

History

I-35 was part of the Interstate plan approved in 1957 and was built through the 1960s and later. The decision to split the route into eastern and western branches through Dallas-Fort Worth and the Twin Cities reflected the need to serve paired cities and large populations on both alignments rather than choosing a single path.

Growth in cross-border trade after the 1990s increased traffic on the southern segments, and the route became a focus of freight and corridor planning between Mexico and the interior of the country.

Major cities and places

Notable features

• Lake Superior waterfront at Duluth
• Laredo border gateway

Did you know

• Splits into I-35E and I-35W through both Dallas-Fort Worth and the Twin Cities.
• Crosses six states from the Mexican border to Lake Superior.
• Carries heavy international trade freight through Laredo.
• Ends at the Lake Superior waterfront in Duluth, Minnesota.