The Big Alta 50K course is a premier single-loop race route, offering extensive scenic views along some of the highest points in all of Marin County.

The course is very challenging, many long ascents and steep descents. The route is composed of a rugged mix of dirt double track fire roads and single track trails along extensive ridgelines, down deep ravines, across hilly open grasslands, wildflower meadows and oak woodlands.

The 50K race offers a stunningly beautiful and tough trail race experience!