The Big Alta
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The Big Alta : March 19–21, 2027
The Big Alta is a three-day trail running event in Marin County, California, staged at Marinwood Community Center & Park. The event is produced by Daybreak Racing and Freetrail and offers multiple race options across a single race weekend.
Courses traverse many of the highest points in Marin County and include landmarks such as Loma Alta and Big Rock Ridge. Runners can expect point-to-point and single-loop formats with extended views across the San Francisco Bay Area.
Distances offered:
- 100K point-to-point course
- 50K single loop
- 28K single loop
The 50K and 28K fields are limited to 300 participants each; the 100K is limited to 400 participants. Registration is handled through Ultrasignup and opens September 14. The 2027 Big Alta 100K is designated as a Western States Endurance Run qualifier.
Race services listed by the organizers include chip timing with live splits, staffed aid stations, shuttle buses for the 100K (shuttle pass available for purchase), professional medical support, on-course photography, custom finisher awards, and post-race food and beverages. Transfers to another person are not allowed; races do not use a lottery and a waitlist will open if a race fills.
100K participants must upload the current course GPX file to a navigation device and carry it on race day. Organizers may impose mandatory gear requirements in inclement weather; examples include a rain jacket, emergency blanket, whistle, ID, 400 calories of nutrition, and at least one liter of hydration. Visit the organization's website for the most recent information.
