Rock Creek is a tributary of the Potomac River, in the United States, that empties into the Atlantic Ocean via the Chesapeake Bay.

[2] The creek rises from a culvert under Dorsey Road at the north edge of Laytonsville Golf Course in Montgomery County, Maryland.

It flows underneath the Intercounty Connector, which crosses it on a large arch bridge visible from the trail.

This area, which the company dubbed "Rock Creek Basin",[4]: 251  silted up and was dredged several times for the Canal's use.

[5] In Maryland, most of the northern Rock Creek watershed has good to excellent water quality, according to studies conducted by the county government.

[14] In 2006, the National Park Service finished a project to remove or bypass eight fish barriers in the creek by adding a fish ladder to bypass the 1905 Peirce Mill Dam, modifying historic fords, and removing abandoned sewage lines and fords.

The effort was designed to restore American shad, river herring, and other migratory fish to the creek and their historic upriver spawning grounds.

As of 2014, ongoing restoration projects in the watershed include the Broad Branch and Klingle Run tributaries.