High Country
The whole area before you is an extremely large Caldera.
A Caldera is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber collapses leaving a large depression. The large depression can then fill with water. Crater Lake in Oregon is an example.
This is in a remote area East of the Eastern Sierra. Cher and I were out exploring and came upon this location. An amazing place. We camped here. Why not.