"Of all the paths you take in life, make sure a few of them are dirt."

I searched for keywords of that text in his books online and on an electronic copy of Muir of the Mountains, and was unable to find it. On rare occasions we find something in Muir's unpublished journals that is new and which can be verified. So I also did a search of the John Muir Papers at the University of the Pacific, and once again came up empty

pacific.edu | Widening the search on the Internet, it appears that the quote is frequently attributed to John Muir but is also fairly often just listed as "anonymous" or "Unattributed." | This quote does not sound like anything John Muir would have said. He did not write that way.