I came across an amazing gem via the Colorado Railroad Museum website.
On April 21, 1958, Mac Poor, famed author of DSP&P and co-author of the Pictorial Supplement to the DSP&P, recorded the audio of an interview between himself and George Champion, the man who piloted the final rotary snowplow through Alpine Tunnel. This journey occurred between December 31, 1909 and January 4, 1910.
It is stunning to hear from a man who was there along with hearing Poor's voice as the two record this historical memory for posterity.
Enjoy!