In October 2012 Nevada public health officials investigated an outbreak of Campylobacter infections among participants of a long-distance obstacle adventure race held on a cattle ranch in Beatty, Nevada. A case-control study was conducted and results showed a statistically significant association between inadvertently swallowing muddy surface water during the race and Campylobacter infection. Twenty-two participants were ill. Four participants laboratory confirmed with Campylobacter coli.