Krakauer tends to repeat himself. To some extent, this is necessary. For instance, because there are so many people to keep track of in the book, and because some of those people have the same names, he'll often introduce or describe them several times. That much seems forgivable, even helpful. Occasionally he'll also repeat descriptions. Everyone does it, but when he repeats particularly memorable or creative descriptive phrases, they jump out at you.
These are very minor literary lapses, of course, and I don't want to make a mountain out of them. It's a damned good book, and I should be so lucky to write something like it some day.