Multnomah County

Administrative district of northwestern Oregon; area 1,204 sq km/465 sq mi, population (1990) 583,900. The county is bounded on the north by the Columbia River, which forms the border with Washington State. It is Oregon's most urbanized and populous county, and is dominated by Portland, the county seat.

Suburbs of Portland occupy much of the western part of the county. The Willamette River flows through the city, emptying into the Columbia River. The remainder of the county is agricultural (yielding fruit, market garden produce, cereals, and dairy goods), or is heavily wooded. Mount Hood National Forest is in the east.