Cajon Pass: Lost Lake...

That small body of water toward the top-left of the frame is the actual lake.  I did not walk over to the lake itself, as I was more curious to see where the trail (pictured on the right side of the frame) would take me. 

Naturally, legend has it that the lake is bottomless.  In truth, the lake is fed by underground springs, and it does, indeed, have a bottom.

Photo taken using DJI Phantom 4 drone.  June 30, 2018.