was led by American Rivers and the Maryland Department of Natural Resources. Now that Bloede's Dam has been removed, removal of Daniels Dam upstream on the mainstem Patapsco River would open to anadromous fishes the remaining of Patapsco River mainstem, the entire length of the South Branch Patapsco River, of the North Branch Patapsco River up to the Liberty Dam, and many of these rivers' tributaries. Water quality The eastern portion of the Patapsco River is in a highly urbanized area and is subject to extensive stormwater runoff and other forms of water pollution. The Maryland Department of the Environment has identified the Lower North Branch as containing high levels of heavy metals (chromium, arsenic, cadmium, copper, mercury, nickel, lead, selenium, and zinc), as well as phosphorus, fecal coliform bacteria, and PCBs. The Piney Run Reservoir on the South Branch of the Patapsco is polluted by excess levels of phosphorus and sediment. Clean-up efforts by the residents of surrounding communities have been led by environmental nonprofit organizations, such as The Friends of Patapsco Valley & Heritage Greenway, Inc. (PHG). From 2006 to 2012, PHG volunteers participated in 183 stream clean ups, removing 264 tons of trash from the streams of the Patapsco Valley watershed. Recreation There is recreational swimming in areas of the Patapsco River, sometimes involving rope swings, inner tubing, and wading. The river also serves as a venue for rafting. The Patapsco is also great for fishing. Parts of Patapsco State Park stocked in the early spring by MD DNR, and offer some pretty decent trout fishing. The Northern Snakehead has also made the Patapsco their home. They can be found from historic Ellicott City all the way into the harbor. They're a great fighting gamefish, and are absolutely delicious. Crossings This is a list of all crossings of the main stem of the Patapsco River and selected crossings of its three main tributaries. Listings start downstream and continue upstream to the sources of the rivers. See also Patapsco Vallis, a valley on Mars named after the river in Maryland Bloede's Dam List of Maryland rivers List of parks in the Baltimore–Washington metropolitan area Liberty Reservoir References Chesapeake Bay Program Watershed Profile: Patapsco/Back River Patapsco Valley State Park External links Maryland DNR's Surf Your Watershed: Patapsco/Back River American Rivers, a nonprofit conservation organization Maryland Port Administration Blue Water Baltimore, formed in 2010 from a merger of the Gwynns