September 1 - October 26, 2025

Iron Will Double Slam

619 S Lincoln

Enterprise, KS 8 Races 50 Days, 7 Races 43 Days, 6 Races 36 Days

Registration closes: Sun, Aug 31 @ 11:59PM CT

The Iron Will Double Slam – A Test of Pure Grit

Get ready for the challenge of a lifetime with the Iron Will Double Slam, where only the toughest trail warriors earn their place in this relentless series of 100-mile races! It’s not just a test of endurance—it’s the ultimate journey of grit, resilience, and pure willpower.

The Mission

Can you conquer 8 x 100-milers over 50 days, pushing your body and spirit to their limits? With three levels of glory, you decide how far you want to take your double-slam dreams:

  • 8/50 – The Pinnacle: 8 races, 800 miles, 50 days
  • 7/43 – Still Savage: 7 races, 700 miles, 43 days
  • 6/36 – The Warrior’s Path: 6 races, 600 miles, 36 days

No shortcuts, no breaks—you’ll have to lace up, show up, and conquer each 100-miler, one week at a time, all in a row.

Your Challenge Awaits:

Here’s the lineup for 2025’s epic Double Slam series:

  • 9/6: Hawk 100
  • 9/13: Iron Will 100
  • 9/20: Ultra Palooza 100
  • 9/27: Your Choice - Cowboy 100 or Tulsa Urban 100
  • 10/4: Hennepin 100
  • 10/11: Heartland 100
  • 10/18: Pumpkin Holler 100
  • 10/25: Extravaganza 100

Each race stands alone as a brutal test, but to conquer this series, you’ll have to master all (or most!) of them in a row. No stops, no skips—just consecutive 100-milers pushing you to the edge of your endurance and beyond.

Registration & Entry

Registration is open until September 1, 2025. To make it official, sign up for the Double Slam at just $10 plus UltraSignup fees. You’ll receive a 25% off code for the Iron Will 100, and discounts for the other races in the series may be available!

Each race maintains separate registration and is subject to the entry requirements & terms specified by each race director

The Rewards:

Finishers will have the option to earn a custom plaque, celebrating your hard-earned achievement. Complete the full 850, and your plaque will highlight your grit, your times, and your name in bold. Tackle the 743 or 636? Your plaque will honor your success as well!

You MUST complete 8/7/6 consecutive 100’s to receive a finish result and be award eligible.

The Legacy Begins Here

This isn’t just a race series. The Iron Will Double Slam is a journey of endurance, an adventure for those with an unstoppable spirit. It’s not about who’s the fastest; it’s about who has the Iron Will to go the distance.

Ready to go big?

Event's current local time: 4:00 AM CT

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