Rising up from the depths of Lake Chabot, the Bad Bass (a strangely kilt-wearing, bagpipe-playing Scottish bass with teeth) shows itself once again on July 18th 2026! Why is he Scottish? What is he doing in Castro Valley? How can he play bagpipes with his fin? We have no idea how to answer those questions. Why is he so bad-to-the-fishbone? Maybe he just knows how awesome the trails of Lake Chabot really are!
Whatever the Bad Bass is doing here, we hope you'll join us at the beautiful Lake Chabot Marina in Castro Valley for the scenic Bad Bass 5K, 10K or Half Marathon!
Registration fees
Where pricing applies, shown amounts include mandatory charges, items, and fees.
5K
Price changes in 30 days 10 hours-
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Register for 5K$74.84Now registering May 11 – Jun 22
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$80.18Jun 22 – Jul 18
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10K
Price changes in 30 days 10 hours-
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Register for 10K$84.45Now registering May 11 – Jun 22
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$89.79Jun 22 – Jul 18
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Half Marathon
Price changes in 30 days 10 hours-
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Register for Half Marathon$103.66Now registering May 11 – Jun 22
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$109.00Jun 22 – Jul 18
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Remote Runner
Price changes in 1 month 5 days-
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Register for Remote Runner$60.96Now registering Oct 11 – Jun 27
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$66.30Jun 28 – Jul 18
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Event schedule
- Sat, July 18, 2026 7:30 AM - Hiker start (for those walking the half marathon, planning to take longer than 3.5-4 hours)
- Sat, July 18, 2026 8:30 AM - Half Marathon
- Sat, July 18, 2026 8:55 AM - 10K
- Sat, July 18, 2026 9:10 AM - 5K
Contact information
- Event contact
- Race Director
- Website
- Visit website
