This is the inset map for Poplar Bluff from the 1957 official state highway map. Numbered routes shown on this map were US 60, US 67, US 160, and Missouri 53 (in red); and Missouri 142 and Missouri 158 (in dark red). A supplemental route, PP, is shown in red. This is probably an error, judging by the 1958 inset map of Poplar Bluff.