I would guess the name of the mountain and settlement relate to placer mineral deposits in the area - gold perhaps given some of the history that you've mentioned. Not sure if such info would be worth adding in / looking into. Cheers.
Thanks for the suggestion. I agree with you the Placer name is likely a mining reference. I'll see what I can find. While little is written about the mountains in this range, there is at least one history book published on the area.
I'll see what I can scare up! If you find something, however, please feel free to post it / share it!