Here's the history:
At the top of Sierra Buttes, is this plaque, commemorating the incredible gold mining that took place in the area, with special note of a 106 pound nugget that was found here. Woah.

Up some very-steep stairs, you reach the tippy top of Sierra Buttes, where you find this rock, inscribed by miners during the gold rush.

Note the old-fashioned writing style!
OK, and here's the thrill (to put it mildly):

That there is a
rattle, at the end of a looong snake. I startled it, and it scared the living daylights out of me. It slithered one way, and I
leaped the other! Hubby had some warning (my scream), so he was collected enough to take this photo.