Iowa Route 149 is a north-south route in the southern half of eastern Iowa. It almost functions as a southern extension of US Route 151, continuing south of Interstate 80 to Ottumwa. The northern end is indeed at Interstate 80, west of US Route 151's southern terminus, at Williamsburg, Iowa. From there Iowa Route 149 heads primarily south, with several westerly jogs mixed into its route. The southern end of Iowa Route 149 is at US Route 34 in Ottumwa. The southernmost portion, beyond the bypass route of US Route 63, is concurrent with US Route 63's business route through Ottumwa.