From big races to Saturday morning group runs—find 10k events and connect with the local endurance sports community.
Come enjoy one of our newer routes at Rosaryville State Park in Maryland! New for 2026 – a half marathon at this venue!
Please note that there is a daily entry fee for Rosaryville State Park and runners are responsible for paying the fee.
Conveniently located right off the Capital Beltway, Rosaryville State Park in Upper Marlboro, MD offers fun and challenging terrain, that is also beginner friendly. Not overly technical in nature, this race course is perfect for an early season trail running race.
The race course at Rosaryville is beautiful and fun and winds through mixed hardwood forests and fields. The trails are twisty, relatively smooth, relatively flat and fast. The half marathon course includes the 9 mile perimeter trail, the 2 mile interior trail, and wide open horse trails. The 10K+ course includes 5 miles of the perimeter trail and just over one mile of wide open horse trails. The 5K course consists of part of the perimeter trail and some equestrian trails.
Our charity partner for this event is City Kids. If you are able, please consider making a donation to this amazing organization during registration.
USA Swimming Club.