U.S. Federal Route 20 is a east-west highway in Northern Woodbury County. From east of Moville to the Iowa/Nebraska State Line, it is a multi-lane highway. U.S. Rt. 20 passes through the following towns in Woodbury County. Correctionville Lawton Sioux City U.S. Rt. 20 is multi-plexed in Woodbury County. U.S. Rt. 75, at Sioux City.
Branches of U.S. Rt. 20 in Woodbury County. EB I-129/U.S. Rt. 20; NB U.S. Rt. 75 at the Iowa/Nebraska State Line. BGS's on NB I-29. EB U.S. Rt. 20/NB U.S. Rt. 75 east of I-29/129. EB U.S. Rt. 20/NB U.S. Rt. 75 on the southeast side of Sioux City. BGS on EB U.S. Rt. 20/NB U.S. Rt. 75. A BGS on WB U.S. Rt. 20.