Don't tell anyone, but what really happens is that one of Roger (no "d") Hogan's trained eagles grabs your mail in its talons and flies it from Osier north-northwest to the Skyline Lodge at Platoro - thirty miles up the dirt road from the bottom of La Manga Pass - where it waits several days for the weekly stagecoach to take it over the pass to South Fork (during the winter, the low-level route to Monte Vista is used). From there, it is loaded onto the once-weakly SLRG mixed from Alamosa, whence your mail is eventually transferred to the U.S. Post Office in Antonito ...
So there is a 1/14 chance that your mail will travel on a gen-u-ine steam-powered R.P.O. !