Difficult Run
| Difficult Run | |
|---|---|
| The Cross County Trail crossing the stream at Difficult Run | |
| Location | |
| Country | United States | 
| Location | Northern Virginia | 
| Physical characteristics | |
| Mouth | |
|  • location | Potomac River | 
| Basin size | 57.7 sq mi (149 km2) | 
Difficult Run is a 15.9-mile-long (25.6 km) tributary stream of the Potomac River in Northern Virginia in the United States.
The stream is part of a 57.7-square-mile drainage basin, or watershed, in the north-central portion of Fairfax County, Virginia. Difficult Run flows through Great Falls Park, where it has been characterized as "a miniature Mather Gorge and Great Falls." The stream picks up speed as it runs through a steep gorge with waterfalls, and drains into the Potomac.
The wildlife includes 163 species, depending on the season, and 41 soil types are found on the trail and alongside the stream.
Used for many purposes since the early 1800s, the area is today used for hiking, biking, fishing, boating, climbing, and bird watching.