The Umpqua River ( ) on the Pacific coast of Oregon in the United States is approximately long. One of the principal rivers of the Oregon Coast and known for bass and shad, the river drains an expansive network of valleys in the mountains west of the Cascade Range and south of the Willamette Valley, from which it is separated by the Calapooya Mountains. From its source northeast of Roseburg, the Umpqua flows northwest through the Oregon Coast Range and empties into the Pacific at Winchester Bay. The river and its tributaries flow entirely within Douglas County, which encompasses most of the watershed of the river from the Cascades to the coast. The "Hundred Valleys of the Umpqua" form the heart of the timber industry of southern Oregon, generally centered on Roseburg.