Sean O'Brien 100K

JAN

30

2027

A multi distance trail race in Calabasas, CA on January 30, 2027. The event includes a 100K that is a 2026 WS100 qualifier and entry fees range from 152.60 to 323.00 USD.

Sat 30 Jan 2027

Calabasas, California

Website

100 kilometers 50 miles 50 kilometers 26 miles 30 kilometers

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Sean O'Brien 100K and related trail races

The event takes place on January 30, 2027 in Calabasas, CA at 1925 Las Virgenes Road. It is a series of trail races organized by Keira Henninger Events and offers multiple distance options for runners.

Distances offered include:

100K
50 Miler
50K
Marathon
30K

The 100K distance is listed as a 2026 WS100 qualifier. Registration for the event closes on Tuesday, December 1 at 11:59 PM PT. Entry fees are shown in a range from 152.60 to 323.00 USD. The organizer lists multiple pricing options for entries and indicates availability for those offers beginning in mid 2026.

The event is presented as an offline, in person trail race in Calabasas. Media and course view points are noted for various miles along the route. Practical details such as exact start times are provided by the organizer but are not included here. Visit the organization's website for the most recent information.

100 km

100k

50 mi

50 Miler

50 km

50k

26 mi

Marathon

30 km

30k