▁ ▁- ▁Al lied ▁Chem ical ▁Canada ▁ ▁N MC X ▁- ▁National ▁Mach in ery ▁Company ▁ ▁N M GR ▁- ▁New ▁Mexico ▁Gate way ▁Rail road ▁ ▁N ML X ▁- ▁National ▁Metal ▁Corporation , ▁Ltd . ▁ ▁N M OR ▁- ▁Northern ▁Missouri ▁Rail road ▁ ▁N MR X ▁- ▁New ▁Mexico ▁Department ▁of ▁Transport ation ▁- ▁New ▁Mexico ▁Rail ▁Run ner ▁Express ▁ ▁N MS X ▁- ▁New ▁Mexico ▁Ste am ▁Lo comot ive ▁and ▁Rail road ▁Historical ▁Society ▁ ▁N N ▁▁ ▁- ▁Nev ada ▁Northern ▁Railway ; ▁Northern ▁Nev ada ▁Rail road ▁ ▁N NI U ▁- ▁N aut ica ▁Line ▁ ▁N N PU ▁- ▁Niger ian ▁National ▁Pet role um ▁Corporation ▁ ▁N NS X ▁- ▁New port ▁News ▁Sh ip building ▁and ▁D ry ▁D ock ▁Company ▁ ▁N N W ▁- ▁Neb r aska ▁North western ▁Rail road ▁ ▁N N Y X ▁- ▁National ▁New ▁York ▁Central ▁Rail road ▁Museum ▁ ▁NO DM ▁- ▁Mexico ▁North ▁Western ▁ ▁N OF U ▁- ▁N od f os ▁ ▁NO GC ▁- ▁New ▁Orleans ▁and ▁G ulf ▁Coast ▁Railway ▁ ▁N OK L ▁- ▁North western ▁Oklahoma ▁Rail road ▁ ▁N OK R ▁- ▁North western ▁Oklahoma ▁Rail road ▁ ▁N OK Z ▁- ▁First ▁Union ▁Rail ▁ ▁N OL R ▁- ▁New ▁Orleans ▁Lower ▁Coast ▁Rail road ▁ ▁N OL U ▁- ▁Ne pt une ▁Orient ▁L ines ▁ ▁N OL Z ▁- ▁Ne pt une ▁Orient ▁L ines ▁ ▁N OP B