The 9th running of the Stone Mill 50 Mile is on November 17, 2018. 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.

Registration will open on May 1, 2018!!!!!

 “THANK YOU …2017 Runners and Volunteers…only hope you guys had half the fun as John and myself out there….GREAT DAY!”  Barry, RD


Results     2017      Photos

List of all Finishers from the beginning through 2016 (pdf): By Name | By Distance

2017 Course

Click on map to see larger version

See the Course on Strava.

2018 Course Preview Training Runs

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.

Address: 9715 Washingtonian Blvd.  Gaithersburg  Maryland  20878  USA
Phone: 301-987-0900

Alternative Hotel
Sleep Inn: $95 Queen bed or $103 for Double – ask for Stone Mill rate.

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 17, 2018. 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 16th 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).

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 & John 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.