By the time Northern Pacific box cars like these (with their roofwalks having been removed during routine maintenance) began to appear in the mid-1960s, NP was already preparing for merger with Great Northern, Burlington Route and Spokane Portland & Seattle. GN and NP each owned half of CB&Q and SP&S respectively. The merger occurred in 1970. While the 1960's saw the simplification of most diesel paint schemes, freight car lettering became ever grander with this large version of the NP "monad" logo being an excellent example. Many survived well into the 1980's.