 The race is limited to 150 participants; registrants must qualify by completing at least a 50-mile run in the previous year.The race starts in Wrightwood, following portions of the Pacific Crest Trail (where it climbs Mount Baden-Powell), the Silver Moccasin Trail, and the Gabrielino Trail.It finishes at Loma Alta Park in Altadena, CA, near NASA's Jet Propulsion Laboratory.