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Sean O'Brien 100/50M/50k/26.2/30k

Name: Sean O'Brien 100/50M/50k/26.2/30k
Start: 2026-01-31
End: 2026-01-31
Location: Calabasas

Calabasas, California, United States

calendar_today 31 Jan, 2026

directions_run Running

language Official Website

sell $95.00 – $190.00

About the Event

Tackle the iconic and demanding trails of the Santa Monica Mountains at the Sean O'Brien Ultra-Marathons, a premier event set for Saturday, January 31, 2026 in Malibu Creek State Park. This legendary race offers a spectrum of distances from a 30k to a grueling 100k, with the 50 Mile serving as a Sterling Silver Ticket race for the Angeles Crest 100 and the 100k as a coveted qualifier for the Western States Endurance Run.

Runners will navigate a challenging, cupless course through some of Southern California's most breathtaking and rugged terrain, requiring self-sufficiency and resilience. With staggered early morning start times, the event captures the serene beauty of the coastal range, testing both physical endurance and mental fortitude across its world-class routes.

Directed by renowned ultra-runner Keira Henninger, this race is a cornerstone of the winter ultrarunning calendar, attracting elite athletes and dedicated trail enthusiasts alike. It's a true test on historic trails where every finish represents a significant achievement in the sport.

Races Offered

100K

Jan 31, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

05:30

sell

$190.00

50 Miler

Jan 31, 2026

straighten

Distance — 80.5K

terrain

Type — Running

timer

06:00

sell

$150.00

30K

Jan 31, 2026

straighten

Distance — 30K

terrain

Type — Running

timer

07:00

sell

$95.00

50K

Jan 31, 2026

straighten

Distance — 50K

terrain

Type — Running

timer

07:00

sell

$115.00

Marathon

Jan 31, 2026

straighten

Distance — 26.2K

terrain

Type — Running

timer

07:00

sell

$105.00

Weather History

These values represent the 3-year monthly averages for January in Calabasas.

thermostat Temperature

7.1° / 16.8°

wb_sunny Feels like

3.7° / 13.6°

light_mode Avg sunshine hours

8h 18m

water_drop Avg rainfall

4.2 mm

ac_unit Avg snowfall

—

air Avg wind speed

9.3 km/h (Light breeze)

opacity Sweat loss rate

Low

terrain Course conditions

Firm and slightly soft

sunny Max UV Index

Low (2.0)

humidity_mid Humidity

60.3%

wb_twilight Sunrise

07:57

nightlight Sunset

18:08

About Calabasas

Learn more about the host city, Calabasas.

Calabasas is a suburban community at the southwestern corner of the San Fernando Valley of Los Angeles County, sitting in the foothills of the Santa Monica Mountains to the south.