The Big Alta 2026 is a trail running event taking place from March 19 to March 22, 2026, in Marinwood, United States. The event is staged at the Marinwood Community Center & Park in the San Rafael, CA area, featuring three distinct distances: 100K, 50K, and 28K. Participants can expect challenging trail terrain through Marin County's famous landscapes, with panoramic views of the San Francisco Bay Area. The weather in late March in coastal Northern California typically brings daytime highs between 55-75°F, with morning lows in the 40s. Conditions can vary throughout the day, with possibilities of sun, breeze, clouds, wind, fog, or rain showers. The courses are designed to summit many of the highest points in Marin County, including landmarks like Loma Alta and Big Rock Ridge, offering runners a mix of technical trails and breathtaking vistas.
What distances are available for this event?
→100K race starting on Saturday, March 21
→50K race starting on Friday, March 20
→28K race starting on Sunday, March 22
What are the event dates and race formats?
→The event takes place from March 19 to March 22, 2026
→The 50K is a single loop with a mass start at 8:00 AM on Friday, March 20
→The 100K is a point-to-point course starting at Fort Baker on Saturday, March 21, with a mass start at 6:00 AM
→The 28K is a single loop with a mass start at 8:00 AM on Sunday, March 22
What are the course details for each distance?
→The 50K is a tough, single-loop course that summits many of the highest points in Marin County
→The 100K features a world-class point-to-point course with endless vistas across the San Francisco Bay Area, including summits of Loma Alta and Big Rock Ridge
→The 28K is a shorter but equally challenging loop with spectacular Bay Area views and technical trails
What are the finish line cutoff times for each race?
→The 50K has a finish line cutoff at 4:30 PM on Friday, March 20
→The 100K has a final cutoff at 11:00 PM on Saturday, March 21
→The 28K has a finish line cutoff at 1:30 PM on Sunday, March 22
What are the key logistics for the event?
→The staging area is at the Marinwood Community Center & Park, 775 Miller Creek Road, San Rafael, CA 94903
→Parking is available curbside along Miller Creek Road near the Marinwood Community Center
→The nearest airports are San Francisco International (SFO) and Oakland International (OAK)
What are the mandatory requirements for the 100K race?
→100K runners must upload the course .gpx data file to their GPS watch or smartphone navigation app (such as Gaia, Strava, or Caltopo)
→Inclement weather gear is required if activated by Thursday of race week, including a running pack, rain jacket, smartphone with course info, emergency blanket, whistle, ID, 400 calories of nutrition, 1 liter fluid capacity, hat or bandana
What is the weather expectation for the event?
→Late March in coastal Northern California typically has daytime highs between 55-75°F and morning lows in the 40s
→Weather conditions can vary throughout the day, with possibilities of sun, breeze, clouds, wind, fog, or rain showers
→Participants are advised to come prepared for changing conditions
What is the pet policy for the event?
→Leashed, friendly dogs are allowed at the staging area only
→Dogs are not permitted on the race course
What is included in the race experience?
→A finish line celebration at Marinwood Park each day with meal, beverages, podium awards, and a sponsor swag raffle
→Event t-shirts and hats from Territory Run Co are available for purchase during registration (not included in entry fee)
→Swag must be picked up at the race; unclaimed items will be sold on race day
What is the course preview and live tracking information?
→A course preview is available through the Freetrail Strava Club
→Live tracking is provided via Ultralive.net
→Official results will be posted to Ultrasignup after the event concludes
