The Columbia County Courthouse, located on 341 E Main Street in Dayton, is the oldest working courthouse in all of Washington’s 39 counties. When the courthouse was completed in 1887, Washington was still a territory.
During the 1970s, Daytonians began taking steps to preserve the town’s rich architectural history. In 1975 the courthouse was listed on the National Register. In 1984 a large scale restoration program for the building began, with the goal of returning it to its nineteenth-century splendor. Restoration was completed in the summer of 1993. The cupola was returned to the roof and the scales of justice once again rose above the front entrance of the building.