There appears to be a strong Celtic connection at the Inyo site. This premise is bolstered significantly with the recognition that there is a deliberate ogam message constructed within this sunsymbol. This sunsymbol exists on a panel with unique positional characterists. It is what one may consider a billboard, positioned to be seen, and apparently read on the summer solstice.
There is a singular feature of Stonehenge that is in scientific agreement. That is the alignment to the rising of the sun over the "heelstone" as viewed on the summer solstice. There was a purpose to this visual metaphor. Out of pure curiosity, I arranged to be onsite the sunrise of the sumer solstice to see if a similar alignment was incorporated. As the sun rose, I positioned myself to place the lone prominent natural pillar below the rising sun. Hampered by the damage to the cliff, one could not make it work exactly. However in times past to view the event, your necessary position placed this panel directly in front of you.
The construct of the sunsymbol suggests there is a message concealed within. The rays are organized, not haphazzard. Two "rays" diagonally cross and truncate into a third. This is obviously a deliberate design. It would be quite reasonable to begin with the Celtic alphabet, Ogam and a root Celtic language, Gadelic to attempt a read the sunsymbol.
There are other icons present on the panel that may direct a persons attention to the solstice by memonics. There are six parallel lines. The solstice divides the year into 6 months. Below that and appearing to be an even older work is a bisected circle, the year, halved.