As it enters Cedar County, it passes West Branch, the birthplace of and site of the library and museum of President Herbert Hoover. It approaches the Cedar River near the village of Rochester. Just east of the river crossing, Iowa 38 joins I-80 from the north. The county road that continues to the south from Iowa 38 leads to Moscow. The two highways travel together for until they reach the Wilton area. Here, Iowa 38 exits to the south, while US 6 joins I-80 for the last time.