Multnomah County was created when the people living in Portland found it difficult to travel to Hillsboro to conduct business at the county seat of Washington County. They also thought that they were paying too much in taxes to support the farmers in the rural areas surrounding Portland. In 1854, Portland businessmen petitioned the Territorial Legislature for a new county and Multnomah County was created at the subsequent session. The county was named after the Multnomah Indians who were part of the Chinookan tribe that lived on the eastern tip of what is now Sauvie Island in the Columbia River. The City of Portland was chartered in 1851 and made the county seat in 1854. The Multnomah County Commissioners met for the first time on January 17, 1855.
Multnomah County is Oregon’s smallest and most populous county.