Rosaryville Half Marathon
Upper Marlboro, United States • 28 Mar 2026
Trail Running in Upper Marlboro
The Rosaryville Half Marathon, 10K, and 5K Trail Run take place within Rosaryville State Park in Upper Marlboro, Maryland. Located near the Capital Beltway, the event utilizes a variety of trail systems including mixed hardwood forests and open fields. The terrain is characterized as twisty and relatively smooth, featuring flat sections designed for speed. The trails are not overly technical, making them accessible for different experience levels.
Participants can choose from several distance options held on the park's trail network:
- Half Marathon: A 13.5 mile course including the perimeter trail, interior trail, and horse trails.
- 10K: A 6.7 mile route using the perimeter trail and wide equestrian paths.
- 5K: A 3.6 mile run consisting of portions of the perimeter and equestrian trails.
- Virtual Races: Remote options for 3.1 miles, 6.2 miles, and 13.1 miles.
The half marathon course specifically encompasses a nine mile perimeter loop and a two mile interior trail, supplemented by wide horse trails. The 10K+ route covers five miles of the perimeter scenery. The event partners with a charitable organization named City Kids, which supports youth programs. Registration for the physical trail races typically closes in early January, well in advance of the March race date. Visit the organization's website for the most recent information.