Weaving and rambling across the various rolling and steep hills of Jefferson County’s White Ranch Park, the Sawmill Trail Runs serve as an ultimate test for December running. Runners will enjoy a single loop for 27k, or the double for 55k. The route uses nearly all of the trails in White Ranch Park and boasts a challenging 4,229′ of elevation gain per loop.

The Sawmill Trail Runs quickly became an iconic HPRS Fat Ass starting in the winter of 2013. After 4 incredibly successful and adversity filled years, we decided to turn the event into an official race. It’s too good not to be a winter ultra offering in Colorado. While turning the event from Fat Ass to Official Race, we wanted to reward participants with a race with a “Fat Ass feel,” all while allowing them to gain points towards the Fat Ass Series (for members) and our Adversity Cup (everyone).  

Course Overview:

5th Annual
 December 9, 2017

Distances: 55k (33.6 mi) or 27k (16.8 mi)
33 Mile Gain/Loss: +8,458′ / -8,458′
16.5 Mile Gain/Loss: +4,229′ / -4,229′
Start Time: 7:00am
Time Limit: 10 Hours (Both Distances)
Location: Golden, CO
Start/Finish Location: White Ranch Open Space & Mountain Park, Lower Lot (Glencoe Valley Road)
Runner Limit: 200
CLICK HERE for a detailed course profile

Special Event Notes

• We are excited to offer this event at a heavily discounted rate for our members, making it Colorado’s cheapest 55k. We’d love those who are non-members to become members of HPRS in order to take full advantage of member benefits. Please refer to our entry fee structure below to see how it pays to be a member
• The Sawmill Trail Runs is the first race eligible for points towards Human Potential’s 2018 Adversity Cup. You do not need to be a member of HPRS to participate in the Adversity Cup and you’ll be added automatically. For more info on our Adversity Cup, CLICK HERE
• It is also the first race in Human Potential’s 2018 Transcendence Series
• HPRS Members participating in this race will also receive points towards The Human Potential Fat Ass Series
• This is also a Fat Ass Series “Bad Ass Weekend,” HPRS Members who run in the race will acquire points towards their Fat Ass Series totals, and are also afforded the opportunity at “Bad Ass Points” the following day. See our Fat Ass Series Page for more info. 
• Accruing points via the Fat Ass Series also provides members an opportunity at bonus points in the Adversity Cup
In other words.. Members running in the Sawmill Trail Runs have a chance to gain points towards the Adversity Cup, Points towards the Fat Ass Series, Bonus points towards the Fat Ass Series if they run again the next day, and potential bonus points towards the Adversity Cup. 

Entry Fees:

Our Only Race With A Flat Registration Fee Regardless of Distance
2018 HPRS MEMBER: $55 (No additional discounts please – this is the member price)
RACE DAY REGISTRATION: $65 For Members & $105 for Non-Members.
We’ll be hosting membership registration the day of the race!

Because Only 2018 HPRS Members may take advantage of member pricing,
and 2018 Membership opens on October 1st, we’ll open registration for this event on the 2nd.
When you register as a member you will receive an email with the discount code for the race.


Become a member first and save! Membership pays for itself!
Non-Members are encouraged to register as an HPRS member prior to registration.
To learn more about or to become a HPRS Membership CLICK HERE.

Pace Membership = $20 making your total race registration $75
Crew Membership = $35 making your total race registration $90
Adversity Membership = $55 making your total race registration $110
To learn more about member benefits, check out our Membership Page by CLICKING HERE
HPRS Members receive 10%-25% off all other HPRS Races!

Register before Tuesday, November 28, 2017 to receive a shirt and finishers award.
Those who register after this date will not receive a shirt, and an award only as available.

Online Registration Closes December 6, 2017 at 11:59:59pm

Support Jefferson County Open Space!
HPRS gives $5 from every race registration directly to Jefferson County Open Space.
During your registration process, you’ll have the option to donate additional funds to JeffCO OSMP
You can donate $5, $10, $20, or $50 extra dollars. Help us support JeffCO and their amazing trail network!


Course Details:

COURSE: The course starts and finishes at the lower lot of White Ranch Open Space and Mountain Park. It is a figure 8 loop on mostly single track trail and partially on double track fire road. Those finishing one loop will complete the 27k option (16.8 miles). Those finishing two loops will complete the 50k+ option (33.6 miles). The second loop is run in the reverse direction of the first. 

STRICT CUT-OFF: Only those who complete their first loop by 11:45am (4:45 run time) will be allowed to continue on to a second loop. The course cut-off is 5:30pm in order to be considered an official finisher of the event. (Maximum splits of 4:45 split for 1st half and 5:45 split for second half)

AID STATIONS: This race will feature just two aid locations. The 1st aid location is in the upper lot of White Ranch Open Space. Runners will access this aid station 1x for the 27k, and 2x for the 55k. The other aid station will be at the lower lot doubling as the Start/Finish Line. Those in the 55k will access this aid station 1x. Therefore, runners in the 27k will benefit from 1 aid stop, while those in the 55k will benefit from benefit from 3.

CREWS AND PACERS: No pacers or crews for either distance at this event. Due to access difficulty and limited parking, we are unable to accommodate either. Those who ignore this rule will be listed as DNF in the official results for the race.

Parking: All runners and spectators must park at the designated parking locations ONLY. A map of these areas will be available closer to the race.
We highly encourage all runners to please CARPOOL! to the event. This helps limit our impact on other trail users. More information on carpool options will come close to race day. PLEASE CARPOOL!

Pre-Race Check in: Packet and bib number Pick-Up will take place from 6-6:45am at the Start/Finish Area. All runners must check-in with race staff the morning of the run by 6:45AM. Runners not checked in by 6:45 AM will not be scored as official runners of the event.

We’ll also have a fire at Town Hall from 6-8p on Friday Evening (conditions permitting). Please BYOB and Bring Your Own Camp Chairs.

Pre-Race Briefing: Race morning at the starting line at 6:45am

Post-Race Celebration: There will be a post race gathering TBA

Awards: All official finishers will receive a unique finishers award. We’ll also present special awards to DFL, Best Blood and a few surprise awards as well.


Permits: This event is being held in accordance with permits from Jefferson County Open Space & Mountain Parks. We ask that you please respect and care for the land this event is held on to help ensure the future of this race and to limit our environmental impact.

Any additional race information, changes, and updates will be sent to registered entrants ONLY via e-mail communication.