Hi Jeff. Yep, that's the photo exhibition I remembered. After my initial posting to this board about old City Cemetery, there's been a lot of research carried out by city-sponsored archeologists. Turns out there was a formal policy of leaving behind unclaimed graves when the cemetery was turned into Lincoln Park Golf Course in 1909.
The City of SF has proposed making the old cemetery a landmark to further protect its remaining "residents" -- who may number over 15,000.
Proceedings on the landmark status are slowly wending their way through the various review stages as I write this.