The Big Alta
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The Big Alta
The Big Alta is a three-day trail running event produced by Daybreak Racing & Freetrail in Marin County, California, held March 19, 20 and 21, 2027. The event uses marked courses that summit many of Marin County’s highest points, including course landmarks Loma Alta and Big Rock Ridge, and offers extended views across the San Francisco Bay Area.
Three race distances are offered:
- 100K point to point course
- 50K single loop course
- 28K single loop course
The staging area is Marinwood Community Center & Park; the 100K starts at Fort Baker with an optional shuttle bus from the staging area available for a fee. Participant parking is curbside along Miller Creek Road; the Marinwood Park lot is reserved for officials and volunteers. Friendly leashed dogs are allowed at the staging area but are not permitted on course.
All race registration is handled through UltraSignup. Field sizes are limited: the 50K and 28K each allow up to 350 runners and the 100K allows up to 400. The 100K requires runners to have the current course GPX file uploaded to their navigation device and carried on race day. Inclement weather may trigger additional mandatory gear requirements. Live tracking and results are provided during the event. Every finisher receives a custom award and a sponsor raffle is conducted during race weekend. Visit the organization's website for the most recent information.
