Lewis County was created from Vancouver County on Dec. 21, 1845. In 1844, effort was made to establish two counties north of the Columbia River, to be named Lewis and Clark. But the bill passed by the provisional legislative assembly provided for one county named Vancouver. Lewis County was named after Captain Meriwether Lewis of the Lewis and Clark Expedition.
Lewis County originally included territory west of the Cowlitz River, between the Columbia River and latitude 54' 40". Since then Lewis County has been subdivided several times and new counties grew from these subdivisions. The United States Great Britain Boundary Treaty (1846) caused the northern boundary of Lewis County to be changed from latitude 54' to latitude 49' and down the middle of the Straight of Juan de Fuca. In 1851, Pacific County was created from the southeast corner of Lewis County. In 1852, Thurston County was formed from the northern portion of Lewis County.
In 1851 and 1852 the legislative assembly formally recognized the county board of commissioners as a legal body, changed the times of holding court in the Third Judicial District (Lewis, Clatsop, and Clark counties), redefined the eastern boundary of Lewis County, and established the land claim of Fred Clark as a temporary county seat. The county seat traveled between the homes of various county officials until 1862, when Claquato became the seat of county government. The town of Saundersville, renamed Chehalis in 1879, became the county seat in 1872.
In 1853, an act was passed which authorized the board of commissioners to levy a road tax. On March 2, 1853, Washington Territory was created and Lewis County was no longer under the jurisdiction of Oregon Territory.
Series Descriptions for Lewis County
1849
.1 cubic feet
Calendar Microfilm
Series used to document county population and to report statistics to the territorial government. Census rolls show residents name; number of legal voters, adult males and females, males aged 10 to 21, females aged 10 to 18, and males and females under age 10; totals; census date; and census taker's certification. Series is not arranged.