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

Wild Rose Half Marathon & 5K in Roseville on May 16, 2026 offers a half marathon on the Pleasant Grove Bike Path and a 5K through William Hughes Park. Paved courses include multiple aid stations and post-race swag including a technical shir..

Experience the final 70 miles of the Western States trail during this three day training event featuring supported runs of 19, 20, and 32 miles through iconic canyon terrain and mountain climbs.

A trail event on the El Dorado Trail in Placerville on May 23, 2026, offering distances from a kids run to a half marathon, paved and unpaved sections, aid stations, color-coded course markings, and medals for finishers.

A 10km trail run on the Olmsted Loop at Auburn State Recreation Area in Cool, California on June 6, 2026. The race takes place the same day as the Coolest Ride and Tie and Equathon events.

Add Event
Help us complete the calendar!
  • Distance is at least 5 km
  • Event has a website or Facebook page
Website
Optional: Please provide your e-mail address if we may contact you.
Report a change
We will only update the data if the information is also on the website.