The Darién Gap has challenged adventurers for many years. A 1962 expedition with three Chevrolet Corvair rear-engine cars two support trucks completed the trip south Chicago through to the Colombian border. A 1971–72 British expedition from Alaska to Argentina attempted to transit the Gap with two standard production Range Rovers, supported by a team of Land Rovers. They barely succeeded in thrashing a passage through the extreme terrain. In 1979, a team led by Mark Smith drove standard production CJ7-model Jeeps from South to North, traversing the Gap with difficulty. In 1984, Loren and Patty Upton made the first "all land" vehicle crossing of the Gap. It took 741 days of slogging, winching, chopping, and digging their way through the inhospitable jungles of the Darién Gap.