The Ultimate Boulder County MTB Challenge
After years of underground legend status, The Cougar Slayer returns! What started in 2012 as a self-timed Strava event has grown into Boulder County's most notorious mountain bike challenge.
"The course of the eponymous underground, unsanctioned, unofficial, mountain bike race/adventure."
This epic journey takes you from the mountains to plains on Boulder County's best and most obscure mountain bike byways, combining technical singletrack, challenging climbs, and breathtaking descents.
July 1 - August 31, 2025
Complete the course anytime during the race window
Optional organized group ride: Mid-August
Entry Fee: $75 via Venmo; include your username in the note & email to receive the route.
Account: @bouldercougarslayer
Strava: Public profile required
Completion: Multiple attempts allowed; t-shirt included for completion
Winner Takes All: Fastest time wins entire prize pool (minus cost of t-shirts)
Recognition: Top 10 featured on leaderboard
Special Awards: Best photo i.e. a cougar
Timing: Official Strava segment
Submission: Share activity link
Equipment: GPS device required
Fair Play: Single continuous effort
The Cougar Slayer route is classified - keeping the underground spirit alive!
Route details, waypoints, and navigation files will be provided to registered participants only.
What we can tell you:
Route secrecy is part of the challenge!
Full route details, GPX files, and t-shirts are provided only to registered participants. This maintains the underground nature of the event and ensures proper preparation.
"Bring headlamp just in case!" - Advice from previous participant
This is an 8+ hour commitment. Weather can change rapidly. Be prepared for all conditions.
Excellent mechanical condition required. Full suspension recommended.
MANDATORY - No exceptions. Your brain is irreplaceable.
3+ liters minimum. Consider hydration pack + bottles.
8+ hours of fuel. Bring more than you think you need.
Spare tubes, tire levers, multi-tool, chain tool, pump/CO2.
Phone with Strava app + GPS. Handlebar mount HIGHLY recommended.
Essential backup. You may be riding in dark conditions.
Rain jacket recommended. Mountain weather changes quickly.
The 2025 Cougar Slayer revival is organized anonymously, by two Boulder County MTB enthusiasts committed to honoring the race's underground legacy while establishing professional organization.
"What a day! Route finding galore. HIGHLY recommend a handlebar phone mount for navigation. Pinch points halfway through. Bring headlamp just in case!"
"An amazing adventure taking you from the mountains to plains on some of Boulder County's best and most obscure mountain bike byways."
The 2025 race results will appear here as they come in!
Race results will be posted here during the competition period
July - August 2025