Rick O'Donnell Memorial Ultra Challenge

River's Edge Endurance Challenge is a nonprofit running event held at Brunswick Middle School, Maryland. The lineup includes a 5K (3.1 miles), a 3-Hour Endurance Race, and a 6-Hour Endurance Challenge. The largely trail-based course runs on the River's Edge Trail System, with about a mile on school..

The Fall Harvest 5k is a scenic trail race held at Claude Moore Park in Sterling, Virginia. Set amidst the vibrant colors of autumn, the course features forest paths and leaf-covered trails, offering a picturesque experience for both runners and walkers. This event is part of the Run Your PRCS Parks..

MoCo Dems 5K Fall FunRun is a 5K run/walk at Agricultural History Farm Park in Derwood, MD. Organized by the Montgomery County District 15 Democratic Caucus, it offers a 5K for adults, a Youth 5K, and a free option for youth 10 and under. The course is a natural trail through the park, with water st..

Patapsco Valley 50K is an annual ultramarathon held near Baltimore, MD, with race headquarters at CCBC-Catonsville. The in-person event offers a 50k and a 25k, plus virtual options, set on a scenic, historic, well-marked trail course through Patapsco Valley State Park. The race features five aid sta..

EX2 Adventures' Fall Backyard Burn Trail Run at Riverbend Park in Great Falls, VA offers 5-mile or 10-mile trail options along the Potomac River just west of Great Falls National Park. The course features riverside singletrack, a few short hills, and non-technical terrain with scenic views; elevatio..

The MCRRC Stone Mill 50 Mile Run is a 50-mile trail ultramarathon in Montgomery Village, Maryland, organized by MCRRC. The course uses forested, rolling terrain along the Seneca Greenway and Muddy Branch trails in Montgomery County, primarily on single-track dirt trails with small stream crossings...