Interstate 29 (I-29) is a generally north-south interstate highway that serves the Great Plains region and the upper Midwest between Kansas City and Winnipeg, Manitoba, Canada. The highway’s total length is 755.51 miles.
In the south, I-29 begins at Kansas City, Missouri, at a junction with I-35 and I-70. It runs northward to the U.S.-Canada border near Pembina, North Dakota. The highway follows the course of three major rivers, each of which forms the borders of U.S. states. The southern portion of I-29 closely parallels the Missouri River from Kansas City northward to Sioux City, Iowa, where it crosses and then parallels the Big Sioux River. The northern third of the highway closely follows the Red River of the North.
Along its length I-29 connects a number of major cities, including (from south to north) Kansas City, Missouri; Council Bluffs, Iowa; Sioux Falls, South Dakota; and Fargo, North Dakota.
The official route numbering for the National System of Interstate and Defense Highways was adopted on August 14, 1957. At that time, there were two separate routes that are now Interstate 29. The southern segment ran between Kansas City and Sioux Falls. The northern portion ran from Fargo to the Canadian border and was designated Interstate 31. Two months later (October 18, 1957), interstate system additions were approved, including 230 miles of highway linking the two routes, and which was then numbered I-29.
I-29 in Missouri
Construction of I-29 in Missouri began at the bridge site for Pigeon Creek south of St. Joseph in early 1957. The last segment of the highway was completed in Missouri on July 28, 1976; an 18.7-mile portion of the highway opened in Atchison County. The total cost for the interstate in Missouri was $112 million.
Interstate 29 runs for 130.72 miles in Missouri. The southernmost 5.5 miles of I-29 parallels I-35 north from the “Alphabet Loop” that encircles downtown Kansas City. I-35 branches eastward, while I-29 turns west toward Kansas City International Airport and a short overlap with I-435, which is known as the Kansas City Beltway.
After leaving the Kansas City area, I-29 runs north through low rolling hills to St. Joseph. There, an urban loop (I-229) serves downtown St. Joseph while I-29 bypasses the city to the east. The highway bends northwest to Mound City and southwest Iowa while running parallel to the Missouri River.
I-29 in Iowa
As is the case for most interstate highways, I-29 opened in stages in Iowa. The first section extended from U.S. 20-77 to the South Dakota state line and opened on October 1, 1958. The last segment of the highway to open in Iowa was from the Missouri state line north to County Route J-64 on August 31, 1973.
Although I-29 does not enter Nebraska, bridges across the Missouri River connect the I-29 corridor with Nebraska City and Plattsmouth on the drive north to Council Bluffs. Once in Council Bluffs, I-29 parallels I-80W before following an S curve northward to Interstate 680. I-680 previously ran concurrently with I-29 for 10 miles. However, the overlap was dropped when the eastern branch of I-680 (formerly I-80N) was renumbered as I-880 in November 2019.
I-29 shifts westward again toward the Missouri River. The highway travels through flat areas of land while running to Sioux City. The highway parallels the east bank of the river near downtown Sioux City; I-129 provides a western link to South Sioux City, Nebraska. Within Iowa, I-29 runs for 154.75 miles. Just north of Sioux City, I-29 crosses into South Dakota.
I-29 in South Dakota
The longest segment of Interstate 29 is in South Dakota; the highway runs for 252.50 miles through the state. Segments in the state opened in stages between the late 1950s at Sioux Falls and 1982, when the segment between exits 224 and 246 was completed.
I-29 turns again at Junction City as it makes its way northward to Sioux Falls, which is located in southeastern South Dakota. I-229 is an urban loop that carries traffic east to downtown, while I-29 runs westward through Sioux Falls’ suburbs. A number of easterly and westerly turns occur between Sioux Falls and Brookings, where South Dakota State University is located.
As I-29 continues north-northwest from Brookings to Watertown, there are few traveler services. The long stretches of highway between exits and good sight lines were why the speed limit was increased to 80 miles per hour along this stretch of the highway to the North Dakota state line.
I-29 in North Dakota
In North Dakota, I-29 runs for 217.54 miles. The landscape remains similar to South Dakota through southeastern North Dakota. Fargo is North Dakota’s largest city, and as I-29 approaches the city, the scenery transitions from rural to suburban and then urban.
On I-29 north of Fargo and its junction with I-94, the highway enters rural areas again until it reaches Grand Forks, the last major population center along the route. The highway continues to the Canadian border north of the town of Pembina. At its northern terminus, I-29 enters Canada and becomes Manitoba Provincial Trunk Highway 75, which leads to Winnipeg.
The final section of I-29 to be finished in the state was from Drayton to Pembina in 1977. When it was completed, North Dakota became the first state to complete all sections of its interstate highways.