The route that is colloquially called The Big Loop is a DC running favorite. Stretching 21 continuous miles around the bulk of the Northwest DC quadrant, The Big Loop is a perfectly designed circuit for a late-stage marathon training run. The backbone of the Loop is a long vertical stretch of the Rock Creek Trail that ultimately merges with on-street running on Beach Drive. The western portion of the Loop is comprised of the entirety of the Capital Crescent Trail and a segment of the Georgetown Branch Trail to the northeast of Bethesda, MD. Runners can connect the southern tip of the Rock Creek Trail with the Capital Crescent by safely following the sidewalks beneath Georgetown’s Whitehurst Freeway.
The Big Loop is well maintained throughout, though runners should always research current trail conditions to check for possible construction and road repair interruptions. The terrain is generally even, with only a slight, gradual incline on the Capital Crescent Trail heading north to Bethesda from Georgetown (Beach Drive and the Rock Creek Trail offer the opposite: a gradual decline as they head south through the city). For the most part, the trail segments avoid vehicular traffic, except for some at-grade intersections on the Georgetown Branch Trail as it runs through Chevy Chase, MD. Also, Beach Drive is open to car traffic during the week (most of it is closed to vehicles on the weekends), so runners should exercise great caution when attempting The Big Loop on weekdays.