P.S. I used to SCUBA dive Tahoe extensively years ago. On several Rock outcroppings at 60 to 90 feet we discovered numerous "Grinding Holes" in multiple locations on dives. An example of "Grinding Holes" in the Sierra's can be found in this article:
https://sierrafoothillgarden.com/201...rra-foothills/ These Grinding Holes are indications that the Lake Level was much lower at some point in history because it takes a while to make the Grinding holes - and one does not grind pine nuts and other items for food underwater.
We never saw the forests because 90 feet was about the maximum one could go (very short stay at that depth) in Tahoe because of accelerated uptake of Nitrogen in the Blood Stream compared to the reduced partial pressures of the atmosphere at 6200 feet - High Altitude Diving is much more complex than diving at Sea Level.