Fourmidable

Auburn, United States • 20 Feb 2027

FOURmidable Trail Races

The FOURmidable event takes place in Auburn, California, with all race distances starting and finishing at Overlook Park. The routes predominantly utilize trails, with less than one mile of road running across all distances. The available race distances include:

  • 50 km
  • 35 km
  • Half Marathon (21.1 km)
  • 13 km

The 50 km course features an accumulative elevation gain of over 6,000 feet. The route incorporates four primary climbs: Cardiac Hill, K2 (also known as Training Hill), Knickerbocker at the Old Auburn Dam Site, and Overlook Hill.

This is a cupless event, meaning participants are responsible for bringing their own reusable cups or water bottles for hydration. Aid stations along the course are staffed by volunteers and provide supplies such as soda, boiled potatoes, candy, gels, electrolyte drinks, and salt tablets.

Available amenities include early packet pickup the day before the race at Overlook Park. On the day of the event, packet pickup is available starting one hour before each race start. Participants may camp in vehicles or trailers at the start area on the Friday night before the event, though ground tents and campfires are prohibited. Parking at the main venue is reserved for registered runners, with additional paid parking located nearby. All finishers receive custom race swag and a post-race meal. Visit the organization's website for the most recent information.

Race information

50 km
Fourmidable 50k
35 km
Fourmidable 35k
13 mi
Fourmidable Half Marathon +
13 km
Fourmidable 13k
Visit the organization's website for the most recent information.
Trail runs nearby

A multi distance trail event in Auburn California from 23 to 26 April 2026 following sections of the Western States Trail. Distances include 161 km, 100 km, 50 km and 25 km and the 100 km awards Western States Golden Tickets.

Trail races inside Marshall Gold Discovery State Historic Park range from a Kids Run to a half marathon on varied singletrack and paved sections, with marked courses, aid stations, and notable elevation gains.

A multi-distance trail event at Browns Ravine Marina on May 2, 2026 featuring 10K, half, 35K and 50K courses on marked single and double track around Folsom Lake. Aid stations are stocked and the event is cupless.

A spring trail race in Cool, California on May 9, 2026, with 5.8 and 10.3 mile single-track courses featuring meadows, hills, a creek crossing, and a tough climb; limited to 600 runners and entries are non-refundable.

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