Description
The center is a few miles SE of Hillsboro. The basin is drained by the Tualatin River and its major tributaries of Gales, Dairy, McKay, and Rock Creeks. It is bounded by the Tualatin Mountains and Pumpkin Ridge on the north, the Coast Range foothills to the west; the Chehalem Mountains to the south; and the west hills of Portland on the east. The 7.5' quadrangles that cover the basin are Laurelwood, Gales Creek, Forest Grove, Hillsboro, Linnton, Scholls, Beaverton, and Sherwood.
History
Tualatin is an Indian word meaning either 'lazy', 'sluggish', or 'land without trees'. The first two describe the Tualatin River; the latter describes the basin itself.