In the epilogue of into the wild, what is the significance of walt and billie visiting the bus in the stampede trail?

In the epilogue of Into the Wild, Krakauer describes traveling with Chris's parents to the site of the bus where he died. Billie and Walt have been devastated by their son's death, but they are both glad to see where he lived and died. They take in small reminders of his presence there and leave a plaque in his memory.

According to Mark Twain, "standards" are the lasting ideas people have, whereas "fashions" are just temporary trends or beliefs that change across the years.

As an example of "standards," Twain cites Shakespeare because, for centuries, his pieces have been adopted and recreated by people worldwide.

As an example of "fashions," Twain considers the different styles of music, writing, and technology being the latter the most changing with the passing of time.