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Stone Mill 50 Mile Run

Gaithersburg, United States • 8 Nov 2025

The MCRRC Stone Mill 50 Mile Run is a challenging trail ultramarathon held in Montgomery Village, Maryland. The 50-mile course features scenic forested and rolling terrain along the Seneca Greenway and Muddy Branch trails, primarily on single-track dirt paths with some small stream crossings. While the course generally drains well, it can be muddy in wet conditions.

The event emphasizes community involvement, asking participants to volunteer six or more hours with local running clubs or related nonprofits before race day. The race is Trail Sisters approved and honors long-term finishers with commemorative apparel. Aid stations and logistical support are provided throughout the course. Visit the organization's website for the most recent information.

United States Maryland Gaithersburg

Race information

Website Registration
UTMB 50K
50 mi
50 Mile
Visit the organization's website for the most recent information.
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