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Mt. Diablo calls!

Plan Your Vertical Weekend!

Climb Up the Ultra Half Series Standings!

COVID-19 Update (3/16/2020):  Because of the new orders relating to COVID-19, we have been ordered to cancel the event.  Registrants have been sent an e-mail with all details concerning the virtual option and future race credit.  A copy of that e-mail can be seen here.

COVID-19 Update (3/11/2020): As of today, East Bay Regional Parks District has confirmed this event can still take place.  Things are very hard to predict right now and changes are possible.  If there are any updates on the status of the event, we will post them immediately and e-mail all participants.

We are offering the virtual race option to anyone who wishes to transfer to it.  If you are taking that option, please e-mail and let us know and we will get that out mail.  With this option, you will receive your race materials in the mail and do your run at your choice of venue and time.

Our race cancellation policy can be found here.

For those coming to the race, you will see a focus on single-serve items at aid stations and at the finish line.  Refill of water bottles and cups will be done by volunteers with gloves and hand sanitizer will be out and available to all runners, should anyone wish to use that.  There will be no shared scoops, tongs or similar items.  This may slightly limit the number of options available to runners.  If there is any item you can't possibly run without, you'll want to make sure you are carrying that with you.

We would expect that everyone is already aware of the best practices, but these are the recommendations local health officials have asked us to remind event participants of:

  • If you are feeling ill, do not come to the event.
  • Wash hands often with soap and water for at least 20 seconds. If soap and water are not available, alcohol-based hand sanitizer can be used.
  • Avoid close contact with other people, including handshakes.
  • Avoid touching your eyes, nose, and mouth.
  • Cover any cough or sneeze with a tissue - if available - or into the elbow.

Discover the beauty of Mount Diablo and support the cause of Save Mount Diablo!

For over 40 years, Save Mount Diablo has worked tirelessly to preserve and increase the open space on and around Mount Diablo. In that time, their efforts have taken us from 6,788 acres of open space to over 100,000 acres of open space on and around the mountain!

With distances suitable for everyone from those hitting the trails for the first time to experienced ultra-runners, the Diablo Trails Challenge was created to help celebrate and support these achievements. A portion of all entry fees will go to Save Mount Diablo to help them continue preserving open space and trails for all of us to enjoy.






Everything you need to know.


Get registered to run.


Conquer your devilish course!


Answers here.


Get ready to run.


Get your official time here.


Provided for free by our volunteer photographers.


Support family, friends and fellow runners.


Join us on April 11, 2020 for our epic 5k, 10k, half marathon or 50k trail runs on Mount Diablo!


The Diablo Trails Challenge is part of the Brazen Ultra Half Series. All half marathon runners are invited to participate.

The series consists of our toughest half marathons. Most measure at least a little (and sometimes more than just a little) longer than 13.1 miles. What really makes them "ultra", however, is the serious ascents and descents and variety of tough trails you have to run to finish them. While flat half marathons are always a challenge, these "ultra-half-marathons" take it to another level!


Thank you to our race sponsors, through their contributions, our sponsors help keep entry costs down and expose our runners their outstanding products and services. Learn more about becoming a sponsor.

There is something about the ritual of the race, putting on the number, lining up, being timed, that brings out the best in us.
Grete Waitz