The first runner to complete the Grand Slam was Tom Green, 35, of Maryland in 1986 in a combined time of 96 hours, 26 minutes, and 28 seconds. At the time, there were only 4 100-mile races in North America. These were the Old Dominion 100 in Virginia, Western States, Leadville, and Wasatch. Two runners completed the series in 1987 and three in 1988. In 1989, the Vermont 100 was added to the series, and runners could choose between it and Old Dominion. Starting in 2003, Old Dominion was removed from the series. In 2008, Western States was cancelled due to forest fires and the Arkansas Traveller 100 was run in its place. Starting in 2017, Old Dominion was once again added to the series and runners have to complete the Wasatch Front 100 Mile Endurance Run and three of the other four races to achieve the award. Today about a dozen runners complete the Grand Slam each year. Entry is limited by lotteries at Vermont, Western States, Leadville, and Wasatch. From 1986 through 2017 there have been 345 official finishers. The fastest time as of 2017 was 69:49:38 by Ian Sharman, 33 of Oregon in 2013. . . In 2015, Junko Kazukawa completed the Grand Slam and the Leadwoman series, becoming the first woman to complete both events in a single year. In 2019, Dion Leonard completed the Grand Slam and the , becoming the first man to complete both events in a single year.
Controversy
Entry into the Grand Slam is administered by the race committee for the Wasatch 100, which is also the last race in the series, normally held in early September. In 2017 entry costs $80 and must be received before the start of the first race in late June. Entered runners who complete the first three races are guaranteed entry into Wasatch without having to go through the lottery. Runners who complete all four races but who do not enter the series are not officially recognized. A list of these so-called "stealth" runners was maintained at https://web.archive.org/web/20120715180450/http://run100s.com/stealth.htm
On Aug. 30, 2013, this page was removed, possibly out of concern that Nick Clark might set a course record without being officially recognized when Wasatch was to be held on Sept. 6-7, 2013. In addition, the following text was added to http://www.run100s.com/gs.htm Kieren McCarthy questioned the legality of the Wasatch committee taking ownership of the trademark rights, noting that the other races in the series are open to anyone and that the trademark is not registered.
