The 11th running of the Stone Mill 50 Mile is on November 14, 2020. 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.

Results     2019      Photos

List of all Finishers from the beginning through 2018 (pdf): By NameBy Distance

2020 Course

Click on map to see larger version

See the Course on Strava.

2020 Race Information
Pre-Registration is Open

*** 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.

2020 National Championship Race

2020 Course Preview Training Runs

hosted by MyMuddyShoes…will cover entire course over 4 outings
Like all of you, we are carefully watching the situation with COVID-19 and monitoring guidance from the CDC and state and local authorities as it pertains to events and large gatherings of people.  At this point in time, we have no reason to cancel the Stone Mill 50 Mile. Every year, our race donates a portion of its proceeds to those local parks and trails who permit us to use their land for this event. As with any event of this nature, the status of Stone Mill 50 will be determined by our ability or inability to obtain permits. Currently, we do not have a permit to hold the 2020 event but anticipate received on closer to to the event date per Maryland rules.
Registration is OPEN for pre-registration waitlist system only. 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.
To Volunteer Click Here

Host Hotel

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
Phone: 301-987-0900
Website: Book from the Room Block

Alternative Hotel
Sleep Inn: $99 Queen bed or higher for Double.

Address: 2 Research Court, Rockville, MD, 20850,

Parking near start/finish area
Parking at Stedwick ES is limited. There is street parking on Watkins Mill Rd, Apple Ridge Rd, and a few other lots. Please consider carpooling. There is a large park and ride at Exit 11 on I-270

When – 6AM Start
The Stone Mill 50 Mile run will start at 6:00 AM on Saturday November 9, 2019. 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 Stedwick Elementary School
The start/finish will again be at Stedwick Elementary School 10631 Stedwick Road, Montgomery Village, MD 20886
The course will follow Watkins Mill Road for 1/2 mile to and from the trailhead.

Packet Pickup
Friday, November 13th at the host hotel, 4:30-7:00 PM & Saturday at Stedwick from 5:00-5:50 AM.

You can still pickup your packet on race day at the starting area if you can’t make it on Friday, but get there as early as possible (by 5 AM).

Bag Drops

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!!

They will be brought back to the school finish ….we will have a riffleford to finish shuttle approximately every 2 hours through the afternoon.

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.

Sorry, no pacers. Our permits with the various park services have a strict limit on the number of runners so we can’t allow pacers.