Having established himself as a top-rank mountaineer with the first American ascent of the Eiger North Face's Original Route in 1962 and the American Direct on the Dru, he conceived of climbing the Eiger by the direttissima (Italian for most direct) route. Two thousand feet from the summit his rope broke and he fell to his death. The Scottish mountaineer Dougal Haston, who had been climbing with Harlin, reached the summit with a German party which joined forces to follow the same route, afterwards named the Harlin route in his honor. The story of the climb was recounted in the book by British author (and ground team member) Peter Gillman and Dougal Haston.