Lag Bon 10K

Lag Bon 10K : March 22, 2026

The Lag Bon 10K is a trail running fundraiser held at Lake Lagunitas Picnic Area at the end of Sky Oaks Road, Fairfax, CA. The event benefits Evidence Action's Safe Water Now program: ticket sales collected in excess of event costs will be donated to that program. The course is a 10K trail with approximately 400' of elevation gain and loss. Runners will encounter stairs, bridges, roots, rocks and stretches of flat trail. The event will be held rain or shine and participants should expect the possibility of cold, wet and muddy conditions. No dogs or strollers are allowed. There is a two hour limit to complete the course due to permit restrictions.

Logistics and entry

Space is limited to 100 runners. Registration opens January 1, 2026, and there is no race-day registration; bib transfers are not allowed. Registration fee is $50 and includes an event T-shirt, finisher medal, stickers and GU energy gels or chews. Registrations after March 6 may not receive the requested shirt size. Packet pickup is scheduled for the day before the event at the San Francisco Running Company San Anselmo location. Aid stations and restrooms are located after Bon Tempe Dam at the 3.5 mile point and at the start/finish. Prize gift cards are awarded to top finishers in Men, Women and Non-binary divisions: $50 for 1st place, $20 for 2nd and $10 for 3rd. Visit the organization's website for the most recent information.