Who had the biggest impact on Chris in his journey

This is really up to your own opinion. Everyone on Chris's journey had an impact on him. I like the relationship between Ronald Franz and Chris. Franz is an eighty-year old devout Christian and soldier who picks McCandless up hitchhiking and takes a strong liking to him. He has lost his wife and children long ago, and so feels a fatherly affection for Chris, whom he offers to adopt. There is a tender relationship between these two. I think Franz even gets Chris to consider contacting his family: he tries to convince Chris that it is the right thing to do. Chris, however, does not do this.