Logo

The Big Alta

Lucas Valley-Marinwood, United States • 20-22 Mar 2026

Event Information

The Big Alta is a trail running event in Marin County, California, organized by Freetrail and Daybreak Racing.

The event offers three race distances:

  • 100K, a point-to-point course
  • 50K, a single-loop course
  • 28K, a single-loop course

All three courses are designed to be scenic and summit many of the highest points in Marin County, providing views of the San Francisco Bay Area. The event includes support and a finish line celebration.

Location

The race starts at the Marinwood Community Center in Marinwood, California.

Schedule

The event takes place from March 20 to March 22, 2026. The 50K starts on Friday, the 100K on Saturday, and the 28K on Sunday. Visit the organization's website for the most recent information.

United States California Lucas Valley-Marinwood

Race information

Website Registration
100 km
100k
50 km
50k
28 km
28k
Visit the organization's website for the most recent information.
Trail runs nearby

Mori Point 7K

Pacifica

Run along the scenic Pacifica coastline in the Mori Point 7K. This event features a flat course through the Mori Point National Recreation Area using a mix of trails and paved paths.

Golden Gate Headlands Marathon

Mill Valley

Experience a scenic trail run through the Marin Headlands with panoramic views of the Golden Gate Bridge and Pacific Ocean. Choose between 10K, half marathon, and marathon distances on a course featuring wildflower lined trails.

Diablo Trails Challenge

Walnut Creek

Experience the scenic beauty of Mount Diablo with trail races ranging from 5K to 50K. Support local land preservation while enjoying a professional event featuring a post race BBQ in Walnut Creek.

Romancing the Island Half Marathon

Tiburon

Experience a scenic trail run around Angel Island with panoramic views of the Golden Gate Bridge and San Francisco. This event features a hilly loop course for both Half Marathon and 10K distances with ferry transport included.