I'd like to buy a vowel, please

No trains in this shot, just the path where they once traveled. This is near Likely, California, in the extreme northeast corner of the state. More cows and sagebrush than people and palm trees up here. This is the former Modoc Line, built by the Southern Pacific Railroad to provide a shortcut for Oregon lumber headed east. There was almost no online traffic, since the only population center of any size that it served was Alturas, which isn't exactly a major metropolis. As the lumber traffic diminished so did the need for the line, and in the early 2000s it was closed, and the tracks were beginning to be taken up.

Although the rails and ties have been pulled up and mostly removed, the block signs remained in place.These enabled the train crews and dispatcher to identify where a train was, and insure that it was the only train on that portion of the line at the time. I found it very curious that almost every sign had only the vowels missing. It didn't seem that they would be any less likely to stick to the sign than consonants, so my thinking is that they were gone on purpose. What purpose and by whom I could only guess - aliens? Vanna White?

I'll never know.