Articles

Belgian Ultrarunner Karel Sabbe's Record-Breaking Pacific Crest Trail Run Showcased in New YouTube Documentary

Explore Karel Sabbe's record-breaking Pacific Crest Trail run in a riveting documentary. Jour..

Trail Running: How it Can Help Reduce Stress and Anxiety

Trail running is an effective way to reduce stress, anxiety, and improve physical and mental he..

Trail Running vs. Road Running: Which One Is Right For You?

When it comes to running, there are two primary options to choose from: trail running and road..

Sean O'Brien 100K

Name: Sean O'Brien 100K
Start: 2027-01-30
End: 2027-01-30
Location: Calabasas

Calabasas, United States • 30 Jan 2027

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

This trail running event takes place on January 30, 2027 in Calabasas, California, at 1925 Las Virgenes Road. Multiple race distances are offered on the same day on local trails near the listed address.

Distances offered:

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

The 100K is listed as a 2026 WS100 qualifier. Registration opens on Wednesday, July 1, 2026 at 6:00 AM PT. Additional event materials reference trail views and specific mile markers along the course.

Practical details such as precise start logistics, aid station placement, and exact course profile are not provided here. The event page includes a website reference and map coordinates for the venue address. 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

26.2

30 km

30k

Visit the organization's website for the most recent information.

Trail runs nearby

Saturday Jun 13

ABWR Half Marathon - Glendale

Phoenix Rising features 5k, 10k, 15k and half marathon distances on marked out and back loops in Griffith Park on June 13, 2026. The course uses hard packed dirt trails with an aid station at the turnaround.

Sunday Jun 14

Old Zoo Half Marathon

Los Angeles

12 km

13 mi

A second annual running event at the Old Los Angeles Zoo area on June 14, 2026, offering a half marathon and a 12K on relatively flat, scenic trails. Registration runs November 21, 2025 to January 26, 2026 with fees from $49.

Saturday Jun 20

Tough Topanga

Topanga

6 mi

15 km

Tough Topanga is a SoCalTrail trail race at Topanga State Park offering 15k, 10k, a non-timed Hiker's Delight and a kids 1k, with marked singletrack and fire-road routes, aid stations, prize purses and festival amenities.

Saturday Jul 4

Independence Day Classic

A community July 4 event in Newhall Park featuring a flat, paved 5K along the parade route, a Kid K, and a Masters Mile Walk, with shirts, medals, an expo, and awards benefiting local high school cross-country programs.