The Miwok 100K was founded in 1996 by Kellie Sheehan.
That first race, held on May 6, 1996, had 69 starters and 62 finishers. Kellie directed the race for its first three years; John Medinger took over as race director from 1999, when the race had 142 starters and 125 finishers, through 2003 with 244 starters and 210 finishers.
Tia Bodington took on race director responsibilities in 2004. Since then, the race has grown from 236 starters/205 finishers to 437 starters and 358 finishers in 2014.
The Miwok 100K course has changed a number of times due to a variety of Park Service requirements. In 2012 the race start/finish was moved to Stinson Beach after the event was given notice that the Rodeo Beach dirt parking lot’s return to a natural wetlands was imminent.