The Annual Potomac River Watershed Cleanup has become a decisive catalyst for progress that ignites people’s interest and passion for the environment and community action. The largest regional event of its kind, the Cleanup provides a transforming experience that engages residents and community leaders and generates momentum for change.The Potomac River Watershed Cleanup has grown from a small shoreline cleanup at Piscataway National Park to a watershed-wide network. What started as a few cleanup events along the Potomac River is now a regional event spanning Maryland, Virginia, the District of Columbia, West Virginia, and Pennsylvania.