McKee Bros Limited from Elmira, Ontario, Canada originally introduced their 6×6 as the McKee A.T.V. around 1970. In later 1971 advertisements the name was changed to Roughrider. Although not a widely produced ATV, there are dozens of known survivors.
McKee Article Snowmobiles in Snow Gear – Nov 1970
McKee Announcement – June 1971
McKee Roughrider Ad – Dec 1971