UP Challenger 3983 cutting 6" line?

Hi, At some point I came across the picture of Challenger 3983 under power about ready to roll over what looks like a 6" canvas water line (like from a fire engine) laid across the tracks in front of it. I am trying to find what site I got this picture from. I would guess this picture was taken in the late 1990's or early 2000's based on the cars parked nearby. I think I found the picture while perusing a UP site that documented where each of the steamers they donated for preservation or restoration ended up at. I can find lots of stuff on line aobut 3985, but not 3983, which is pictured under steam.

THanks for any help!