Indeed, it has a DNR name, and a county name. I think the county name is more appropriate in this case. My source for the name comes from this new address notification document: 

https://www.cowlitzinfo.net/WLBldgAddress/DocView.aspx?id=31550485&dbid=0&repo=CCIMAGES&searchid=de4a8fec-a69e-4fd3-b53f-767785dd55af

This demonstrates it is called Davis Peak road, at least up to the fork at Ph-1006A. 