Here are some digital shots of the red/orange Kwiz piece that is circa mid-late 90s painted on a former C&O bridge, most likely sometime after the line was abandoned in 1994. This piece is still visible today, although the efflorescent stains are taking over and it has be clipped by another writer. Wikipedia summary: “Efflorescence is the process where salts migrate to the surface of a porous material, forming a white, powdery deposit.” Photos from 2013-2023.