Tags: Mountain Range.
The Tualatin Mountains (also known as the West Hills or Southwest Hills of Portland) are a range of hills on the western border of Multnomah County Oregon United States. A spur of the Northern Oregon Coast Range they separate the Tualatin Basin of Washington County Oregon from the Portland Basin of western Multnomah County and Clark County Washington.The highest peak in the range is Cornell Mountain at 1270 feet (390 m).