April 18, 2006: North end of US 67 near Iowa’s easternmost point. US 67 is a diagonal route, although its later northernmost segment runs more north-south. For nearly 35 years, 67 defined the eastern curve of Iowa from Davenport to Dubuque, running concurrently with US 52 for no particular reason.
Two of the numbers are out of place sequence-wise, but Iowa has every odd US route number from 59 to 71, plus 75 and 77.