 US 30 enters the western end of Iowa by crossing the Missouri River on the Blair Bridge , located east of the Nebraska town of the same name . Adjacent to the highway bridge is the Union Pacific Railroad 's river crossing for the Overland Route . The highway runs roughly parallel to the rail line for its entire run across Iowa . For nine miles ( 14 km ) , traffic moves through the flat Missouri River bottoms , passing DeSoto National Wildlife Refuge on the way to Missouri Valley . At Missouri Valley , it intersects Interstate 29 ( I @-@ 29 ) at a partial cloverleaf interchange . It enters the Boyer River valley through the Loess Hills , a region of wind @-@ deposited silt extending from north of Sioux City to extreme northwestern Missouri . The rolling Loess Hills rise 50 – 100 feet ( 15 – 30 m ) above the roadway while the land in the valley stays relatively flat . US 30 enters Logan and intersects the eastern end of Iowa Highway 127 ( Iowa 127 ) . The highway runs parallel to the Boyer River as well as the Overland Route in a general northeast direction from Logan . Four miles ( 6 @.@ 4 km ) east of Logan is the western end of Iowa 44 , which extends 105 miles ( 169 km ) east to Des Moines . 
