Sean O'Brien 100K

JAN

30

2027

Trail races in Calabasas on January 30, 2027 offering 100K, 50 mile, 50K, marathon and 30K distances with varied entry fees.

Sat 30 Jan 2027

Calabasas, California

Website

100 kilometers 50 miles 50 kilometers 26 miles 30 kilometers

Always double-check with the organizer's website! This page may contain affiliate links.

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

The event is a multi-distance trail running event scheduled for January 30, 2027 in Calabasas, California. It is organized by Keira Henninger Events and takes place at 1925 Las Virgenes Road. Distances offered cover ultramarathon and road/trail marathon distances.

Offered distances include:

100K
50 mile
50K
Marathon 26.2 miles
30K

Entry fees are listed with a range from USD 152.60 to USD 323.00, with multiple offer options available. Registration closes on December 1 at 11:59 PM PT. The event is listed as an in person event and has entries available as of the published offer details.

The 100K distance is noted as a 2026 WS100 qualifier. Course views and mile-specific vantage points are mentioned for spectators or runners, and the event page references additional resources such as a series website and social media presence for general event information. Visit the organization's website for the most recent information.

100 km

100k

50 mi

50 Miler

50 km

50k

26 mi

26.2

30 km

30k