In regards to the dark Sunday afternoon of September 20, 1950

Hi Betty:
Ian Campbell (CFS Ottawa) passed your message along to me.  The dense smoke
you and many others observed across the northeastern US was indeed the
result of a large fire burning in Alberta.  Although there were a number of
fires burning at that time in Alberta, the largest (the Chinchaga Fire ~1
million hectares) burned throughout the summer (from early June through late
September).  During the September 20-22 period the fire was quite active,
moving 35 km on the 20th an another 26 km on the 22nd.  This would result in
a towering smoke column that would reach into the upper troposphere,
permitting long-range smoke transport.  Smoke was also observed in England
and Holland.
Cordy Tymstra of the Alberta Forest Service has conducted a lot of detailed
research and reconstruction of this fire, has co-authored a paper on it, and
is currently working on a book (Blue Moon, Blue Sun - the Story of the 1950
Chinchaga Fire) which should be really interesting.  His email is:
Cordy. and I will copy him on this response.  He sounds
like the person to answer all of your questions.
I looked through the web site (below) responses to your query.  Quite an
interesting piece of history.  Good luck.

Brian J. Stocks
Senior Research Scientist
Forest Fire and Global Change
Canadian Forest Service
Natural Resources Canada
1219 Queen St. East
Sault Ste. Marie, ON  P6A5M7
Tel: 705-759-5740x2181
Fax: 705-759-5712