Today, the Lexington Herald-Leader's website (kentucky.com) prominently displayed a photo of a KY 1900 marker that is thoroughly coated with whiskey fungus. It's up there as I speak.
First place I ever noticed the fungus was in the valley along I-65 near the KY 245 exit. A lot of the BGSes there have that dark fungus on them. That comes from the nearby Jim Beam distillery at Clermont, from which my dad's brother retired.
I never noticed any fungus in Frankfort when I worked there or on trips in years since then, even though the smell from the Buffalo Trace distillery could be overwhelming sometimes. That is, up until a couple of years ago, when I started seeing the dark spots on some signage on US 127 and US 421. That KY 1900 sign is on US 127 going north out of Frankfort toward Owenton. And judging from the font, it's a reasonably new installation. The older signage at that intersection had taller numbers.
The image for those visiting in future times:
(https://i.imgur.com/3Ax7qmY.png)