That puppy is part of a group of 11 units originally owned by Ontario Hydro (5779-5786), (5860-5862) and were painted for, maintained and operated by CP Rail.
They and 11 other units operated by CN were aquired in 1978 and used to haul coal from B.C. and Alberta to Ontario.
8 of the CP units were transfered to CN in 1996, being renumbered 5388-5395, while the remaining 3 were transfered in 1999 and renumbered 5396-5398.
In April of 2000, 10 units were sold to CP who retained the CN numbers. One unit (#5391) remains on CN's roster.
It appears that most of the units stayed in CP colors for quite some time and and may never have been repainted and that they were returned to CP that way.
Cheers
Terry