The Hughes Hollow within the McKee-Beshers Wlidlife Management Area in Montgomery County, Maryland, is an eBird hotspot known for its variety of birds. There are impoundment ponds and marshes that attract waterfowl, herons, etc. Woodpeckers are plentiful as are sparrows and warblers in their seasons. There is a short walk (0.9 miles - 1.4 km) from the main parking to the Potomac River. Warning: There is hunting allowed in this WMA Monday through Saturday most of the year. Sunday is more relaxing! Here is a satellite view:

Directions:
-Coordinates: 39.08039, -77.40350
-From Intersection of River Road and Route I-495: Google Map