GN Power on 
  Burlington rails was actually quite common at various 
  times. A good resource for this is the last chapter (?Great Northern ? 
  Tourists on Foreign Lines? of ?Great Northern Color Pictorial ? Volume 2 ?? 
  authored by Joseph W. Shine and published by Four Ways 
  West.
  
  GN power 
  shows up on the C&S, FtW&D, CB&Q, as early as 1958. Sometimes it 
  was leased, sometimes it was pooled. 
  
  At one point 
  in time, CB&Q E7?s handled the Empire Builder from Chicago all 
  the way to Havre where they were swapped for F units out of the GN passenger 
  pool for the trip to Seattle and back. On the return 
  trip, the swap was reversed and the Q E?s handled the train all the way back 
  to Chicago.
  
  In return, GN 
  F units on some Eastbound freights were not swapped out in St Paul 
  but ran all the way to just outside of Chicago and 
  return.
  
  There were 
  other arrangements in place in anticipation of the various merger dates.  
  Some arrangements were discontinued as the merger was delayed again, some 
  continued.
  
  The pics in 
  Shine V2 show GN power in various places on the Q system ? worth a look for 
  anyone interested in this topic.
  
  Best 
  regards,
  
  
  Steve
  
  
  Steve 
  Haas
  Snoqualmie, 
  WA