North of Independence, Iowa 150 continues north through the farmland of rural Buchanan County. It passes through Hazleton a few miles before it meets Iowa 281 south of Oelwein. North of Iowa 281, which runs along the Buchanan–Fayette county line, Iowa 150 enters Oelwein along Rock Island Road, which eases into 1st Avenue. A block east of downtown, at Charles Street, Iowa 3 approaches from the east and turns north onto Iowa 150. The two routes head through Oelwein along Frederick Avenue and split a couple miles north of town. The highway turns east very briefly and returns heading north until it reaches Fayette County Road C33 (CR C33). There, it turns east to go through Maynard and continues east until an intersection with Iowa 187. Iowa 187 comes from the south and ends at the intersection, while Iowa 150 turns north and continues towards Fayette.