The 100k is a 2027 WS100 qualifier. Distances being offered are 100k, 50 mile, 50k, Marathon, and 30k. Let's kick off 2027 with an epic race through the Santa Monica Mountains! Thirteen years running and Sean O'Brien still brings some of the best and most challenging trail running in Southern California. We can't wait to have you all on the trails to celebrate with a great day of running.
Jan 30, 2027
Distance — 100K
Type — Running
05:30
$300.00
Jan 30, 2027
Distance — 80.5K
Type — Running
06:00
$250.00
Jan 30, 2027
Distance — 26.2
Type — Running
07:00
$155.00
Jan 30, 2027
Distance — 30K
Type — Running
07:00
$140.00
Jan 30, 2027
Distance — 50K
Type — Running
07:00
$185.00
These values represent the 3-year monthly averages for January in Calabasas.
Learn more about the host city, Calabasas.
Calabasas is a city in Los Angeles County, California, United States. It is adjacent to the southwestern San Fernando Valley neighborhoods of Los Angeles. Situated within the foothills of the Santa Monica and Santa Susana mountains, 29.9 miles (48.1 km) northwest of downtown Los Angeles, Calabasas has a population of 22,491.
Read more launchTours and activities near Calabasas, powered by Viator.
All-time top performances and historical records for Sean OBrien 100K/50M/50K/26.2/30K.
| Place | Name | Year | Time | |
|---|---|---|---|---|
| 🥇 | Christopher Wehan | '17 | 8:24:35 | |
| 🥈 | Ryan Kaiser | '17 | 8:30:01 | |
| 🥉 | Ryan Smith | '15 | 8:41:41 | |
| 4 | Florian Neuschwander | '18 | 8:48:04 | |
| 5 | Bob Shebest | '17 | 8:49:02 | |
| 6 | Seth Swanson | '15 | 8:57:06 | |
| 7 | Bradley Revenis | '17 | 9:00:47 | |
| 8 | Ben Eysenbach | '23 | 9:02:03 | |
| 9 | Brett Hornig | '17 | 9:04:59 | |
| 10 | Charlie Ware | '18 | 9:06:54 |
Read what other athletes have to say about their experience at the Sean OBrien 100K/50M/50K/26.2/30K.
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