Columbia County is named for the Columbia River.
Surrounding County Courthouses:
N – Franklin County and Whitman County
E – Garfield County
S – Wallowa County, Oregon and Umatilla County, Oregon
Created: November 11, 1875 
County Seat:
Dayton 1875 – present
County Courthouse – Dayton
Location: 341 East Main Street / North 3rd Street
Built: 1887 – 1888
Style: Late Victorian
Architect: William H Burrows
Contractor: A J Dexter
Description: The building faces southeast and is a two story gray colored Dexter brick and timber structure. The building is located on landscaped grounds in the center of Dayton. The south front has a small one story portico with balcony. Both front and rear have a 12 foot wide stairway, constructed of embosse cast iron and supported by a concrete foundation. The east and west sides project from the main building. There is a wide eave at the roof line. Above the central south front and north peaks are a bronze Statue of Justice complete with sword and scales. On the east and west peaks are eagle statues. On the center of the roof is a square wood cupola with a railing at the top. In the interior there is wood trim. A central double wooden stairway rises to the second story where the County Superior Court courtroom is located having a 19 foot ceiling. The building houses the County Superior Court and the County District Court. The building experienced a major renovation to restore the exterior ornamental detail between 1991 and 1993.
Note: The County Superior Court – Juvenile is located in Walla Walla County.
Note: The courthouse is the oldest courthouse in Washington still in use as a courthouse. The construction contract for the building was awarded at a price of $32,732. A J Dexter received $10,745, for the stone, brick and concrete work. Kribs, Bishop and Arnold were paid $21,987 for the carpentry work. W H Burrows, an architect, was employed as superintendent of construction for a salary of $1,637. The four steel jail cells in use today cost an additional $3,700. The bricks used in the courthouse were reportedly made of local clay in the local Dexter Kiln.
See: National register of Historic Places – Columbia County Courthouse
See: The Judicial District includes Asotin County and Garfield County.
History: The county was created in 1875 and Dayton was selected as the county seat in 1878. The county used tented premises. The first and present courthouse was constructed in 1886 to 1887 at a cost of $38,067.
County Courthouse – Dayton
County Superior Court courtroom
Photos taken 2009 and 2016