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Sean O'Brien 100K

Calabasas, United States • 31 Jan 2026

Sean O'Brien 100K/50M/50K/26.2/30K : Calabasas, CA

The event takes place on Saturday, January 31, 2026, in Calabasas, California, with a listed venue address of 1925 Las Virgenes Road. It is organized as a multi-distance trail running event offering several race lengths on the same day.

The distances offered are:

  • 100K
  • 50 Miler
  • 50K
  • Marathon (26.2)
  • 30K

The 100K distance is designated as a 2026 Western States 100 qualification race. Registration for the event closed on Wednesday, December 31, 2025 at 7:00 PM local time.

Information presented for the event indicates trail views and specific mile-view locations are part of the course presentation. The event page lists related resources such as directions and entrant information. Details about start times, aid stations, course profile, and participant requirements are not provided here. Visit the organization's website for the most recent information.

United States California Calabasas

Race information

Website Registration
100 km
100k
50 mi
50 Miler
50 km
50k
26 mi
Marathon
30 km
30k
Visit the organization's website for the most recent information.
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