Mark Twain is a person mentioned in the second ¼ of the book Into the Wild.
"Samuel Langhorne Clemens." Bio. A&E Television Networks, 2014. Web. 07 Dec. 2014.
Mark Twain was an author who wrote two very famous books The Adventures of Tom Sawyer and Adventures of Huckleberry Finn. Twain was also a riverboat pilot, journalist, lecturer, entrepreneur and inventor. He was also known as one of America's first and foremost realists and humanists. Mark Twain was born in 1835 in Florida. Mark Twain received no formal schooling but was interested in books and practically taught himself. Twain was a humorous writer and satirical at times as well. One of his books A Tramp Abroad (1880) which consisted of a satirical account of his travels to Germany, Italy and the Alps. Towards the end of his life, Mark Twain traveled and lectured actively, but later died of a heart attack on 21 April 1910 in Redding in Connecticut.
I can see why Mark twain was mentioned in the book because when he was mentioned on page 67 because it showed the passion McCandless had for books and writers like Mark Twain. Since Mark Twain traveled and kept journals I can see how this relates to McCandless and the passion and choices he has in both authors and books.

Mt. McKinley is a thing mentioned in the second ¼ of the book Into the Wild.
Peakbagger.com. "Mount McKinley, Alaska." Mount McKinley. Peakbagger.com, 1987-2014. Web. 07 Dec. 2014.

Mount McKinley (Denali) is the highest mountain in North America and rises almost alone, 16,000 feet above the snowline, but with a total elevation of 20,320 feet. McKinley is also probably the coldest mountain in the world