I remember an article about that, from either “Argosy” or “True”.
***either Argosy or True.***
Two of my favorite magazines along with SAGA.
I think the article was in TRUE.
It is sad that around 1975, TRUE was sold to a porn publisher who turned it into a porn mag. Then it disappeared.
Here it is! Articles by Ivan T Sanderson in both ARGOSY and TRUE.
Minnesota Iceman: Argosy Magazine, May 1969
http://www.bigfootencounters.com/articles/argosy2.htm
Bigfoot Article in True Magazine, 1960
http://www.bigfootencounters.com/articles/truemag.htm
Saga Magazine, July 1970; story written by Frank Hansen.
http://www.bigfootencounters.com/articles/hansen.htm