Based on the Oregon State Archives.
Before 1850 most of Clatsop County's government activity occurred in Lexington. As Astoria grew, activities gradually shifted to that city. Astoria was chosen by electors to be the county seat in 1854 and the first county government sat in Astoria in 1856.
The early sessions of the county court prior to 1855 were held in the homes of county officials and private citizens, first in Lexington and later in Astoria. In 1855 a two-story frame courthouse was completed. The second courthouse was completed in 1908 and is still in use.
The first county government was organized in the mid-1840s with the election of justices of the peace, clerk, sheriff, assessor, and treasurer, and the formation of district courts and the county board of commissioners. In 1964 the county court was replaced by a board of commissioners. The voters of Clatsop County approved a home rule charter in 1988 that called for a board of county commissioners as the policy-determining body of the county and a county administrator to oversee daily operations of the government. The county government currently consists of five commissioners, each elected from one of five geographic districts, and a county administrator and nine departments.
Today, Clatsop County voters elect five commissioners, a district attorney and the sheriff.