,,, At leaste here in OHIO,, a single post office will comprize mant diffrent "mapped" jurisdictions.. To go specifically by U S Post Office may become very confusing. Take Mantua, OHIO 44255,,, there is a Mantua NJ. Okay, butt the 44255 also encludes Alburn Twsp, etc.. The Auburn in Butler County PA will not match with 44255...