The remaining highway between I-82 and Finley in the Horse Heaven Hills was constructed by the state government and Benton County from 2004 to 2008 and was signed as part of SR 397 in 2009.
The remaining section of highway connecting I-82 to Finley in the Horse Heaven Hills was built by the state government and Benton County between 2004 and 2008, and it was officially designated as part of SR 397 in 2009.