Unfortunately I'm not that creative, so I just found it on wikipedia

Kokanee is also another name for the Sockeye salmon. The beer is named after the Kokanee Glacier in the Kootenays region in which Creston is situated.
Creston of course being the town in which the Colombia Brewery is located, where they brew it... Probably has to do with the glacier fresh tasting kokanee slogan.