Follow the Rs and the Ls

It may not come as much of a surprise, but I was skeptical that L and R refer to highways. So I spent a couple of hours digging around on the net. It seems to me that as a matter of fact the "L" and "R" refer to Left and Right on the MRT (Mississippi River Trail). At least according to the MRT website. I pulled up a history of highway naming in the United States, several of them, which followed the development from "Good Roads" to Appalachian Highway Development System and never once found a systematic lettering designation. The letter L was used to refer to the Lincoln Highway, but the metal plaque looks markedly different from the photo. However, there was considerable argument revolving around the change from names to numbers. Many Americans protested numbering a pioneers progress as such, and claimed it was strictly anti-American to number the roads. I was left with the thought that perhaps this internet collab got it wrong, but I wasn't going to say anything.

Yellowstone was founded by Roosevelt... That's a decent enough reason for R.

Actually, another reader discovered that the "L" and "R" were used as left and right turn signs on the Yellowstone Trail. A followup post is in the works.

p.s. - It turns out that 50 years ago my childhood home in MN was on the Yellowstone Trail. Amazing coincidence.