484 definitely ran in 1997 cause we were there, and Earl ran it for us doing some special ops. Now that Earl mentioned below that the flanger derailment was after 1998, I think that event was in the spring of 1999. I believe there were two engines, and 484 nearly went over on its side. I was not there, but I was for the 1997 Rotary(Last run). I am pretty sure you refer to the David Rodgers charters which were in the fall(Tank car train with 463 at Lobato, etc).
We did a video on it called "American Steam In The Rockies", as part of a 5 dvd set "Steam Around the World". My brother shot the video with my old video equipment. We never put it on DVD, and its been so long I don't recall exactly when it was shot. I am pretty sure it was between 1994 and 1996. Neither he nor I were there after 1997 for several years. He was there in 93, 94, 95 for Rotary Runs, but he made a fall trip for the Rodgers charter freights.
Thats why I was thinking 96, but it could have been 94 or 95 also. Sorry cannot nail it down for you.
Greg