As best can be determined, 23 year old Chris McCandles intended to stay in Alaska for about six months, from April until the end of the autumn harvest season, about six months.
According to the 1993 article in "Outside Magazine" penned by John Krakauer, (who would later write "Into the Wild) McCandles, "wanted to be in Fairbanks by the end of April in order to have as much time as possible in the North before heading back to South Dakota to help out with the autumn harvest. By mid-April Westerberg was shorthanded and very busy, so he asked McCandless to postpone his departure date and work a week or two longer. But, Westerberg says, "Once Alex made up his mind about something there was no changing it. I even offered to buy him a plane ticket to Fairbanks, which would have let him work an extra ten days and still get to Alaska by the end of April. But he said, 'No, I want to hitch north. Flying would be cheating. It would wreck the whole trip.'"
McCandless left Carthage on April 15. In early May Westerberg received a postcard of a polar bear, postmarked April 27. "Greetings from Fairbanks!" it read:
This is the last you shall hear from me Wayne. Arrived here 2 days ago. It was very difficult to catch rides in the Yukon Territory. But I finally got here. Please return all mail I receive to the sender.
It might be a very long time before I return South. If this adventure proves fatal and you don't ever hear from me again, I want you to know your a great man. I now walk into the wild.
McCandless's last postcard to Westerberg fueled widespread speculation, after his adventure did prove fatal, that he'd intended suicide from the start, that when he walked into the bush alone he had no intention of ever walking out again."