Interstate 229 (I-229) is a auxiliary Interstate Highway that runs through Saint Joseph, Missouri. It begins southeast of the city at I-29 and U.S. Route 71 (US 71) and travels to the northwest into the city. In St. Joseph, it runs with US 59. Just north of an interchange with US 36, the two routes travel over a viaduct on the banks of the Missouri River. The two routes split at the north end of the viaduct. The interstate ends at another interchange with I-29 and US 71 north of St. Joseph.