FOURmidable Logo

FOURmidable

Auburn, CA

Sat, Feb 13, 2027

In 140 days · Sat, Feb 13, 2027

Don't let race day sneak up

One email during race week. That's it.

When

Saturday, February 13th, 2027

Where

855 Pacific ave, Auburn CA

Distances

Ultra

Typical weather

On this date: rain 2 of the last 10 years

2026

33–49°F

dry

2025

40–61°F

dry

2024

46–59°F

rain

2023

39–62°F

dry

2022

46–60°F

dry

2021

41–53°F

dry

2020

43–64°F

dry

2019

36–49°F

dry

2018

28–47°F

dry

2017

50–54°F

rain

Best months to race in California →

About this race

FOURmidable Trail Run (50K | 35K | Half Marathon+ | 13K)

Presented by SingleTrack Running

Location: Auburn Overlook Park — 855 Pacific Ave, Auburn, CA 95603

Are you ready to test your grit on one of Northern California's premier trail challenges? Hosted in the endurance capital of the world, the FOURmidable Trail Run takes runners through the rugged, scenic canyon trails of the Auburn and Cool areas.

Featuring less than one mile of pavement across all distances, this event treats you to singletrack trails, river canyon views, and the infamous climbs that give the race its name.

The Four Climbs

The signature 50K course packs over 6,000 feet of cumulative elevation gain, headlined by the "FOUR" formidable climbs:

  • Cardiac Hill: A challenging ascent that tests your endurance.
  • K2: Known as Training Hill, a steep climb that prepares you for race day.
  • Knickerbocker: The Old Auburn Dam Site, offering stunning views.
  • Overlook Hill: A final climb that rewards you with breathtaking vistas.

Whether you take on the full 50K ultra or choose the 35K, Half Marathon+ (13.2 mi), or 13K, you will experience the best singletrack Auburn has to offer.

Race Schedule & Start Times

All distances run on race day.

Distance Start Time
50K 8:00 AM
35K 8:15 AM
Half Marathon+ (13.2 mi) 8:30 AM
13K 9:00 AM

What's Included

  • Custom Swag & Bibs: SingleTrack Running takes pride in quality, practical swag designed to celebrate your finish without cluttering your closet.
  • Fully Stocked Aid Stations: Staffed by experienced trail volunteers ready to help refuel and hydrate you quickly. Stations include water, electrolyte drink, gels, soda, boiled potatoes, candy, salt tabs, and more.
  • Post-Race Celebration: Finish at Overlook Park with plenty of hot food, drinks, and trail camaraderie.

Important Event Logistics

1. Cupless Racing

In an effort to keep trails clean and minimize waste, FOURmidable is a 100% cupless event.

  • Requirements: Every runner must carry a handheld bottle, hydration pack, or reusable collapsible cup.
  • No Paper Cups: Paper cups will not be provided at aid stations. Collapsible cups will be available for purchase on-site, or you can bring your own.

2. Packet Pick-Up

  • Early Pick-Up (Recommended): Friday (day before the race) from 3:00 PM – 6:00 PM at the Start/Finish area (Auburn Overlook Park).
  • Race Morning: Available at Overlook Park starting 1 hour prior to your wave start. Note: Any swag/bibs not claimed by race start will be gifted to race-day volunteers.

3. Parking & Vehicle Camping

  • Runner Parking: Primary parking at Overlook Park is reserved for registered runners. Overflow parking is available along Pacific Ave and at the nearby staging area (staging area parking requires a paid fee—please obey posted local signs).

For more information, visit the official race page at FOURmidable.

Course map

Hotels for race weekend

Live prices near the start line, Feb 12 – 14, 2027.

Suggested Races

The IPA Trail Runs logo

The IPA Trail Runs

Granite Bay, CA

Saturday, January 9th, 2027

5K
Trail
View details for race The IPA Trail Runs
The Lost Trail 5K & Half Marathon logo

The Lost Trail 5K & Half Marathon

Granite Bay, CA

Saturday, February 20th, 2027

Trail
View details for race The Lost Trail 5K & Half Marathon
The Gumby 5K & 10K Trail Runs logo

The Gumby 5K & 10K Trail Runs

Granite Bay, CA

Saturday, January 23rd, 2027

5K
Trail
View details for race The Gumby 5K & 10K Trail Runs
The New Year's Duathlon & 5K Run logo

The New Year's Duathlon & 5K Run

Granite Bay, CA

Saturday, January 2nd, 2027

5K
Trail
View details for race The New Year's Duathlon & 5K Run
Escape from Folsom Trail Runs logo

Escape from Folsom Trail Runs

Granite Bay, CA

Saturday, February 6th, 2027

Trail
View details for race Escape from Folsom Trail Runs
The Mighty Dog 10K & 5K Trail Runs logo

The Mighty Dog 10K & 5K Trail Runs

Granite Bay, CA

Saturday, March 20th, 2027

Trail
View details for race The Mighty Dog 10K & 5K Trail Runs
Chanoko 31K, 10K & 5K Trail Runs logo

Chanoko 31K, 10K & 5K Trail Runs

Granite Bay, CA

Saturday, March 6th, 2027

Ultra
Trail
View details for race Chanoko 31K, 10K & 5K Trail Runs
The ICE Breaker Triathlon logo

The ICE Breaker Triathlon

Granite Bay, CA

Saturday, April 10th, 2027

View details for race The ICE Breaker Triathlon
Folsom Lake Sprint & Super Sprint Triathlon logo

Folsom Lake Sprint & Super Sprint Triathlon

Granite Bay, CA

Sunday, May 9th, 2027

Trail
View details for race Folsom Lake Sprint & Super Sprint Triathlon
Folsom Lake International Triathlon logo

Folsom Lake International Triathlon

Granite Bay, CA

Saturday, May 8th, 2027

Trail
View details for race Folsom Lake International Triathlon
The 29th Annual Granite Bay Triathlon logo

The 29th Annual Granite Bay Triathlon

Granite Bay, CA

Saturday, August 21st, 2027

Trail
View details for race The 29th Annual Granite Bay Triathlon
The Good Dog-Dirty Dog 5K & 10K Trail Runs logo

The Good Dog-Dirty Dog 5K & 10K Trail Runs

Granite Bay, CA

Sunday, August 22nd, 2027

10K
5K
1 Mile
Trail
View details for race The Good Dog-Dirty Dog 5K & 10K Trail Runs
Miles for Hope logo

Miles for Hope

Roseville, CA

Saturday, October 17th, 2026

10K
5K
View details for race Miles for Hope
Rio Del Lago 100 Mile + 50K Endurance Runs logo

Rio Del Lago 100 Mile + 50K Endurance Runs

Granite Bay, CA

Saturday, November 7th, 2026

Trail
View details for race Rio Del Lago 100 Mile + 50K Endurance Runs
The Auburn Half Marathon 2026 logo

The Auburn Half Marathon 2026

Auburn, CA

Sunday, September 27th, 2026

Half
5K
Trail
View details for race The Auburn Half Marathon 2026
Apple Hill Half Marathon & 5K logo

Apple Hill Half Marathon & 5K

Camino, CA

Sunday, November 15th, 2026

Half
5K
View details for race Apple Hill Half Marathon & 5K
2026 American River Parkway 20-mile Point-to-Point Marathon Training Run & Taper Program logo

2026 American River Parkway 20-mile Point-to-Po...

Rancho Cordova, CA

Saturday, November 14th, 2026

View details for race 2026 American River Parkway 20-mile Point-to-Point Marathon Training Run & Taper Program
2026 Rancho Cordova PAL Holiday Run logo

2026 Rancho Cordova PAL Holiday Run

Rancho Cordova, CA

Saturday, December 12th, 2026

View details for race 2026 Rancho Cordova PAL Holiday Run
American River Endurance Runs 2027 logo

American River Endurance Runs 2027

Folsom, CA

Saturday, April 3rd, 2027

Trail
View details for race American River Endurance Runs 2027
Way Too Cool 50K & 10 Mile Endurance Runs 2027 logo

Way Too Cool 50K & 10 Mile Endurance Runs 2027

Cool, CA

Saturday, March 6th, 2027

Trail
View details for race Way Too Cool 50K & 10 Mile Endurance Runs 2027

Organize this race?

Claim it free to manage your listing — and get it featured for free, while spots last.

Find The Run Newsletter