Brazen New Year's Eve
About this race
Whether you're looking to squeeze in your first trail run or you're looking to log that 1,000th mile before the clock strikes midnight on 12/31/2026, this is your chance.
Note: This year we will have back-to-back events at Lake Chabot, Castro Valley with a 5K, 10K and half marathon!
New Year's Eve, Thursday, 12/31/2026
New Year's Day, Friday, 1/1/2027*
Make it a double and join us both days and earn the Brazen New Year Mega-Medal!
*Note: Each race is a unique event on its own and requires separate registration.
Pick your distance
Running
NYE 5K
The 5K is entirely on paved trails. The 5K and 10K will essentially be out and back courses, while the half marathon will basically be a loop. All courses include rolling hills that are mostly runnable.
NYE 10K
The 10K is about 50% paved trails and 50% dirt trails. The 5K and 10K will essentially be out and back courses, while the half marathon will basically be a loop. All courses include rolling hills that are mostly runnable.
NYE HALF MARATHON
The half marathon is approximately 30% paved trails and 70% dirt trails. The 5K and 10K will essentially be out and back courses, while the half marathon will basically be a loop. All courses include rolling hills that are mostly runnable. The half marathon will start at 8:30 am and the course will have a time limit of 4.5 hours. All half marathoners must reach the aid station at mile 10.7 by 11:45 am.
NYE REMOTE RUNNER
Typical race-day weather
Based on 8 years of Open-Meteo archive data for this event's race dates in Castro Valley, plus the 3 days either side.
The sun rises at 7:23 AM and sets at 5:00 PM local time (PST) in Castro Valley on January 1, 2027 — 9h 36m of daylight.
Course
No course map published yet.
The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.
Reviews
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Other races near Castro Valley
Different organizers, within 40 miles, in the next three months
Lake Chabot Trail Run
Garin Park XC Challenge
10K On The Bay
Oakland Tech 5km/1 mile Race/Run/Walk Fundraiser
🏃 Plan Your Next Race in Castro Valley
Find upcoming events by distance:
- Castro Valley 5K Races 6 races
- 10K Run Events in Castro Valley 4 races
- Castro Valley Half Marathons 5 races
- Marathons in Castro Valley 2 races
- Castro Valley Running Calendar 2026 7 races
Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.
- Entries, prices, waves and inclusions — the event's official registration page
- Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
- Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
- Comparisons and counts — Race Discovery calendar, 7 Castro Valley events
Spotted something wrong? Tell us and we'll fix it.