What is Diablo 100? It’s a test of human strength & endurance against the most beautiful backdrop of the Mount Diablo State Park located in Clayton, CA. Diablo 100 can be categorized as one of the most difficult long-distance mountain ultras for the following reasons.First, you complete the race entirely on your own without crew or pacers. An aid station will provide the bare essentials of only water & emergency supplies. The rest is up to you.

Second, it has a total elevation gain of more than 15,000 feet, probably surpassing Western States or even Angeles Crest, two of the toughest 100 mile mountain ultras in the West coast.

Third, you run & hike the entire race in 99% technical single or double track trails & fire roads. You’re constantly running up or down.

Lastly, this is mountain (or fell) running at its finest. You reach the next aid station based on your own choice of the most “cost-effective” route. There are no ribbons or markers. You navigate on your own. This is an Ultrahiker event after all.

Are you tough enough for the challenge?

-Andrew Guitarte, Founder & Race Director