Interstate 29: The Midwestern artery that battles the Missouri River's unpredictable floodplains

Countries & Cities · Published 15 October 2026 Swipe more like this →

In short: Spanning from Kansas City to the Canadian border, Interstate 29 serves as a critical corridor for the American Midwest. Yet, this vital highway is defined by its precarious relationship with the Missouri River, which has repeatedly submerged and severed the road, leading to the largest distance-based closure in interstate history.

Interstate 29 stretches northward from its junction with I-35 and I-70 in Kansas City, Missouri, eventually crossing into Manitoba, Canada, to connect with Provincial Trunk Highway 75. Along its path, the highway closely follows the Missouri, Big Sioux, and Red rivers, serving major regional hubs including Sioux Falls, Fargo, and Grand Forks. While the route was originally conceived in 1957 as a shorter segment designated as I-31, planners decided in 1958 to link the highway through the Dakotas, ultimately forming the continuous I-29 we know today.

The highway's geography is both its strength and its greatest vulnerability. Much of the stretch between St. Joseph, Missouri, and Council Bluffs, Iowa, traverses low-lying floodplains. This terrain proved catastrophic in 2019, when severe Midwestern flooding forced a closure of approximately 187 miles of the interstate. This event stands as the most extensive shutdown of an American interstate highway by distance. During the crisis, multiple elevated sections collapsed, while others were completely washed away or submerged, leaving no viable official detours as local rural roads were also underwater.

The route's history is also marked by ambitious connectivity goals. In the 1960s, advocates campaigned to extend the corridor south to New Orleans. While this vision was realized through the creation of I-49, it was assigned a different number to align with the Interstate Highway System's grid-based numbering rules, which dictate that route numbers increase from west to east. Today, I-29 remains a vital link for the region, connecting the four largest public universities in the Dakotas and serving as a major artery for international trade with Canada.

Despite the 2019 disaster, the highway was largely restored by October of that year. The experience highlighted the ongoing challenges of maintaining infrastructure in volatile river basins. While the route remains a primary transit corridor, its vulnerability to the Missouri River's cycles remains a defining characteristic of its engineering and operational history.

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