How is Krakauer able to corroborate (strengthen or support with other evidence) the events in the Detrital Wash?

Chapter 4 introduces us to McCandless’s intense distaste for society abundantly clear. In these chapters, he comes close to rejoining society a few times, going to Los Angeles with the intention of getting a new ID and possibly a job, working in Las Vegas, staying in Bullhead City longer than he has stayed anywhere else, and even working for a McDonald’s using his real name and social security number. Authorities are able to track Chris because of this. Yet each time, he finds himself quickly moving on again, unable or unwilling to reintegrate himself.