Registration pricing
40 Mile Bike
40 mi · 1,691 ft· Starts 12:00 pm
- Early birdEndedOctober 10 – November 1, 2026$130 USD
- StandardNowNovember 2, 2026 – January 23, 2027$140 USD
- Procrastination pricingJanuary 24 – February 5, 2027$150 USD
- Race weekendFebruary 6 – 7, 2027$160 USD
No credit card or processing fees. The price you see is the price you pay.
Register now
Included with your entry
What you get
A supported challenge
Well-stocked aid stations with real food, hydration and volunteers who understand winter.
A hot finish
Every participant gets a hot post-race meal and a cold drink when they cross the line.
100+ chances to win
Find snowflakes along the course and turn them into raffle tickets for serious prizes.
The legendary party
Live music, bonfires, s’mores, vendors and the whole running and riding community.
Training before race day
Join group rides and runs to learn the terrain, meet people and arrive prepared.
Winter rally gear
A custom race bib, event swag and digital offers from event partners.
The course includes a gravel section on Cemex’s private property, only accessible during Old Man Winter.
Our biggest category with 1000+ riders.
Rolling gravel roads, beautiful views of 14ers, a loop around Boulder Reservoir, and life-long memories with 1000+ two-wheeled buddies. This course is a tour of some Boulder County’s best riding, including non-technical gravel riding and scenic views of the Rocky Mountains. There is enough rolling terrain to make the course challenging, but no major climbs or trails on this course. The aid stations at Boulder Res and Butter Ranch will warm you up and keep you fueled before the last stretch back to Lyons.
For those that ride AND run, this is the course that is the bike portion of the Run/Bike Combo.
PRE-RIDING THROUGH CEMEX (mile 2 - 3.6) is STRICTLY PROHIBITED. IT IS PRIVATE PROPERTY & YOU WILL BE ARRESTED FOR TRESPASSING.
Aid Stations:
AID 1 Black Cat Farm: mile 9
AID 2 Boulder Reservoir: mile 20
AID 3 Black Cat Farm: mile 28.5
Know the terrain
The route.
Explore the published map. Routes can change with conditions; follow the final event briefing.
Loads maps from Ride with GPS.
Open 40 Mile Bike route map ↗