Iowa Route 1 runs north-south with a slight northeast-southwest tilt, in eastern and southeastern Iowa. Its northern end is at US Route 151 near Anamosa, east of Cedar Rapids. The southern end of Iowa Route 1 is at Iowa Route 2 just south of Keosauqua, but just north of the Missouri border. Between its endpoints, Iowa Route 1 connects to Mount Vernon, Iowa City, Washington, and Fairfield! Though Iowa Route 1 isn't the busiest or longest highway in Iowa, it arguably has enough prominence to receive the first and foremost state highway number in Iowa. It's very useful to the city home to Iowa's first capitol, Iowa City. Iowa Route 1 links Iowa City to Dubuque via additional usage of US Route 151.
My photo for Iowa Route 1 comes from its southern terminus at Iowa Route 2. The sign assembly shown faces west toward eastbound traffic on Iowa Route 2. This photo was taken on June 30, 2017, at an early part of my early eastern Iowa trip. (The trip spanned a weekend partially in June and partially in July.)