There is an activation report link from Doug (N7NGO) on the SotaMaps Summit summary that is basically the information for driving access and the summit hike. Since there is not a PNWSota report, I thought I'd add a few notes.
The access road(s) are very well graded and certainly Prius friendly, whether coming to the City of Rocks National Reserve from the east (Almo, Idaho) or from the north (Oakley, Idaho).