 On 3 October 1984, climbing in cross-country ski boots as substitutes for his high altitude climbing boots that had been lost in an earlier avalanche, Macartney-Snape and Greg Mortimer became the first Australians to climb Mt Everest, an achievement for which they were both awarded the Medal of the Order of Australia (OAM) for service to mountaineering.Mt Everest historian, Walt Unsworth, described it as "one of the greatest climbs ever done on the mountain" and American climber, John Roskelley, said, "the Aussies pulled off the coup of the century".The expedition was sponsored by Channel 9 who produced a television documentary about the expedition.