Big Bloops Ultra
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Big Bloops Ultra - February 27–28, 2026
The Sixth Annual Big Bloops Ultra is a 24 hour timed running event in Palo Alto, California. The objective is to complete as many laps of the Adobe Creek Loop Trail, known as the bloop, as possible within the 24 hour period. The event runs across two consecutive days in late February 2026.
The bloop is a scenic 5 mile (8 km) loop that passes Adobe Creek, Charleston Slough, Matadero Creek, and Mayfield Slough. The route includes about 1 mile of pavement and 4 miles of smooth dirt. The course is very flat, with under 20 feet of elevation gain and loss per loop. Participants may observe waterfowl such as pelicans, egrets, herons, Canada geese, seagulls, and ducks.
The route begins and ends just north of the Palo Alto Baylands Nature Preserve Trailhead at 2690 Terminal Blvd. Runners may travel the loop clockwise or widdershins; the official score is the number of full loops completed, and partial loops are not counted. The event is free, grassroots, and fully self supported. There are no bibs, no chip timing, no shirts, no awards, and no finisher medals. Water is available along the course, but participants should plan for their own nutrition and hydration. Entry is limited to 24 participants and results will be collected and published. Visit the organization's website for the most recent information.
