Cabin John Creek is a tributary stream of the Potomac River in Montgomery County, Maryland. The watershed covers an area of 26 square miles (67 km2). The headwaters of the creek originate in the city of Rockville, and the creek flows southward for 10.9 miles (17.5 km) to the Potomac River.
The Cabin John Stream Valley Trail follows the course of the creek for 8.8 miles (14.2 km), passing through Cabin John Regional Park and Cabin John Local Park. The Union Arch Bridge carries MacArthur Boulevard and the Washington Aqueduct over the stream about 1/4 mile before the creek flows through a culvert under the Chesapeake and Ohio Canal and empties into the Potomac.
The Cabin John Creek watershed is highly developed, and as a result the water quality in the creek main stem and several tributaries is degraded. Montgomery County Government is formulating a long-term plan to improve water quality throughout the area.
Tributaries of Cabin John Creek
- Booze Creek
- Thomas Branch (also called Beltway Branch and Thomas Run)
- Congressional Branch
- Ken Branch
- Buck Branch
- Snakeden Branch (also called Snake Den Branch)
- Old Farm Creek
- Bogley Branch
- Metropolitan Washington Council of Governments. Washington, DC (1996). Rapid Stream Assessment Technique (RSAT) Survey of the Cabin John Creek and Minnehaha Branch Watersheds, Montgomery County, Maryland: Final Report. December 1996.
Coordinates: 38°58′11″N 77°08′47″W / 38.969833°N 77.146368°W