In 1986, Canada Post and Canadian Pacific issued special stamps and envelopes to honour the completion of Canada's National Railroad.  This envelope is extremely rare as it  has four different CPR locomotives depicted with three different denominations.  The envelope is postmarked both with the Special Ottawa postmark and also postmarked at Craigellachie, B.C. which was the exact location of the Driving of the Last Spike.  This is a very rare item was issued only once 34 years ago.