This looks pretty cool:
Tenzing Hillary Everest Marathon is an International High Altitude Adventure Sports Event being held at Mt. Everest Base Camp, criss-crossing the Highland Sherpa Trails of Khumbu Valley on May 29 every year, to commemorate the historical ascent on Mount Everest by Late Tenzing Norgay Sherpa and Sir Edmund Hillary on May 29, 1953 . Everest Marathon, one of the Toughest Marathon, is open for all High Altitude Running enthusiasts above 16 years of age with sound mind and body.Not sure about the "sound mind" part . . . .