The Diablo Trails Challenge, a 50K ultra-marathon, half-marathon, 10K and 5K will be held this Saturday, April 21st. Course information is here. From the website:

Discover the beauty of Mount Diablo and support the cause of Save Mount Diablo! 5K/10K/Half Marathon and 50K

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 trail 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.