The 11th running of the Stone Mill 50 Mile is completed. Thank you to all the runners and volunteers who supported our race this year. You all did a great job following our COVID plan and keeping everyone safe while enjoying a great day on the trails!
The fifty mile trail run is on the Seneca Greenway and Muddy Branch trails in Montgomery County Md. The course traverses forested, rolling terrain. The course is primarily on single track dirt. There are small stream crossings. Most of the course drains well, but parts can be muddy in wet weather.
2021 Race Information
*** Please continue to review this page for any additional changes or updates to the race. We will keep this page updated with the most current information on the race status.
2021 National Championship Race
Due to COVID, we have deferred the championship event to 2021.
2021 Course Preview Training Runs
There are no training runs this year due to social distancing and the pandemic.
By registering, you are securing your spot to participate, should the race be able to be held. A $0 authorization transaction will be run on your credit card. You will not be charged for the registration until we are able to secure a permit. Once the race is determined a “go” and your card is charged, all sales are final and there are no refunds.
This year our volunteer opportunities are severely limited due to COVID rules. Our COVID plan is very specific and so the RD will be contacting volunteers directly.
SpringHill Suites in Gaithersburg is the host hotel with a discounted nightly rate of $99. Call the hotel to make a reservation and ask for the Stone Mill rate or use the link below for the special rate.
Address: 9715 Washingtonian Blvd. Gaithersburg Maryland 20878 USA
Website: Book from the Room Block
Sleep Inn: $99 Queen bed or higher for Double.
Address: 2 Research Court, Rockville, MD, 20850,
Parking near start/finish area
Parking at Watkins Mill High School is plentiful with additional parking along Watkins Mill Road.
When – 5AM Start
The Stone Mill 50 Mile run will start at 5:00 AM using a wave start based on previous personal times on Saturday, November 14, 2020. The fastest runners will start first to limit overtaking on the course. The cut off time is officially 13 hours or 7:00 PM and will be STRICTLY ENFORCED due to permit requirements and so we can let our amazing volunteers go home. Intermediate cutoffs are
5:10 to Riffeflord….. 8.4 miles to go
3:10 to Rt 28 ….16.4 miles to go
1:25 to Stone Mill…23 miles to go
12:30 to Pennyfield…..26 miles to go…
Where Start/Finish Watkins Mill High School Parking Lot
The start/finish will be at Watkins Mill High School 10301 Apple Ridge Rd, Gaithersburg, MD 20879
The course will loop around the high school before going onto Watkins Mill Road to the trailhead.
Friday, November 12th, outside the host hotel as a drive-through with social distancing in place, 4:30-7:00 PM.
There will be no onsite race day packet pick up due to our COVID plan.
Stone mill will have 2 drop bag locations on race day. The bags will be collected race morning outside the school/start. There will be 2 separate piles:
- Mile 24-Pennyfield lock
- Mile 40-Riffleford road
Please clearly write your last name and bib number on your bag. Our volunteers will attempt to sort them by alphabet. Also please not too large/heavy. Our volunteers are probably not as strong as you are!!
NEW THIS YEAR: The Pennyfield bags will be brought back to the school finish. The Riffleford ones will not be brought back! They become trash after you exit the Riffleford aid station.
Refunds and Bib Exchanges
It’s just not practical to process refunds or bib exchanges. If you decide to withdraw from the race please email Barry and your entry fee will be donated to the State and County parks instead of buying more stuff for the aid stations.
Pacers and Crew
Sorry, no pacers or crew this year. Our county approved COVID plan as well as our permits with the various park services have a strict limit on the number of runners so we can’t allow pacers or crew out on the course for everyone’s safety.