I think I might have found the author.

My research turned up nothing, so I joined a Canadian outdoor adventure forum and asked about him.

I got a couple of responses, and the most promising that meets your criteria is Richard Morenus, a writer of the '40s and '50s. He was from NY, but he wasn't a newspaperman, but a radio and early-TV screenwriter (including working for NBC) who moved to Sioux Lookout, Ontario back in the '40s. His adventures of living six years on an island are in the book, "Crazy White Man," published in 1952 I think, which you can get used for a pretty penny on Amazon or another online bookseller.

He wrote several books, and the other that fits the description might be "Alaska Sourdough" that was popular at that time. But that first one, Crazy White Man, was set in Canada's North Woods when a lot fewer people lived there.

His nearest neighbors at the time were Ojibway Indians, who spoke the language that Grey Owl, mentioned above, learned and used, including when, while touring England, he was introduced to the King of England (whom in truth he had been born a subject of) to help perpetuate the ruse.

So does Richard Morenus sound like the writer?