County in northwestern Oregon, bordering Columbia, Washington, Clackamas, and Hood River counties, and the Washington State border to the north. Largest county in Oregon by population, smallest by land area. 2001 population estimate of 665,810, for 19.2% of the state's population. Land area 435 square miles (1127 square kilometers). County seat located in Portland. Established Dec. 22, 1854. 2000 Estimated real market value $45.5 billion.

Cities in Multnomah County with 1998 Population:

Named after the Amerind village of Multnomah on Sauvie Island. (The name Multnomah was applied to all native peoples of the area.) Sometimes referred to as the People's Republic of Multnomah County after its über-liberal politics. Formed from parts of Washington and Clackamas counties in 1854 by the Territorial Legislature to eliminate need of residents of then-booming Portland to travel to Hillsboro to conduct county business.