Founded in 1983 by Harold Sieglaff, the race has changed over the years in location as well as organization. In its first year, 6- and 12-hour races were offered. In the 1999–2000 event, a 6-day race was offered and reintroduced in 2013–2014. Until 1993 the race was held at Washington High School in Phoenix, after which it was moved to different locations, including a 500-meter certified loop at Nardini Manor in Buckeye, AZ from 2003 until 2010. It has been held at Camelback Ranch in Glendale, AZ from 2011 onwards.
