The Original Wasco County Courthouse was built in 1859 and served immediately as the county courthouse of Wasco. It was one of the two remaining structures of the sort to still exist today that was built prior to the statehood of Oregon.

The Original Wasco County Courthouse functioned as a courthouse from 1859 to 1882 and then became The Dalles city hall from then until 1907. It was the very first courthouse that is located west of the Rocky Mountains.

Moved several times before it was placed in its current location inside the Trevitt?s Addition Historic District, the Original Wasco County Courthouse now serves as a museum under the management of the Wasco County Historical Society. It was also listed on the National Register of Historic Places in 1998.