As he says in the article:
"It is a common fallacy to believe Bigfoot sightings had a beginning and an ending in some presumed hoaxed footprints in California in 1958. The press had a field day a few years ago, when the man suspected of making the prints died. One would have thought that was all there was to it. Nothing could be further from the truth. In my home province of Alberta, for example, sightings go back to at least 1938 in modern times, and to 1811 when explorer David Thompson spotted some prints near present-day Jasper on the Athabaska River."