The Duwamish River is actually the Green-Duwamish River, one of the most complex watershed systems in the country. Its headwaters start in pristine forests in the shadow of Mt Rainier which are cared for by the US Forest Service. The river, as it winds down the mountain travels through forests, agricultural land, residential areas, towns, light commercial industry and ending in the lower portion with heavy industry. As it proceeds to its mouth at Elliot Bay, it collects water from various tributaries and storm drains from the towns and cities which make up the Green-Duwamish Watershed. Much of this drainage has contributed to the significant pollution problems facing the river and its tributaries as they carry various chemicals into the river system.