The Big Alta

The Big Alta

The Big Alta is a three day trail running event in Marin County, California, produced by Daybreak Racing and Freetrail and staged at Marinwood Community Center and Park. The event weekend offers three distinct race options that use the high points and ridgelines of Marin County and include course landmarks Loma Alta and Big Rock Ridge. Runners will encounter extensive views across the San Francisco Bay Area.

Race options include:

• 100K point to point race Western States qualifier for 2027
• 50K single loop course
• 28K single loop course

Registration occurs via Ultrasignup. The 50K and 28K are each limited to 300 participants and the 100K is limited to 400 participants. There is no lottery; transfers to another person are not allowed. A waitlist will open once a race fills. A shuttle bus option is available for 100K runners who need transport to the start. The 100K also requires participants to upload the current course .gpx file to a navigation device and carry it on race day.

The event provides marked courses, chip timing with live splits, staffed aid stations, professional medical support, post race food and beverages for participants and volunteers, custom finisher awards, and official live tracking and results. Visit the organization's website for the most recent information.