We are pleased to announce that the 42nd Mt. Diablo Challenge Ride will be held on Sunday, October 5, 2025

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Last year's event drew 1,017 registrants, ranging in age from 6 to 87, of whom 838 finished the ascent to the summit of the mountain. The event was supported by 9 sponsors, 20 vendors, and 150 volunteers. ​After online registration closes, you can still register on Saturday, October 4, from 2 PM to 6 PM at Trek in Alamo, as well as at the event on October 5. See the FAQs for details.

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WHEN YOU REGISTER FOR THIS EVENT YOU SHOULD RECEIVE AN EMAIL WITH IMPORTANT INSTRUCTIONS. CHECK YOUR JUNK FOLDER IF YOU DON’T GET IT. YOU CAN ALSO READ IT HERE.