Yesterday my son and I were hiking in 3 or 4 year post-burn Chapparal just south-west of the intersection of the Garlock and San Andreas Faults.
We had rehearsed what to do if we encountered a rattlesnake: stop then back away.
Then we found one and got to put that into practice.
It is electrifying to have an ordinary bush begin buzzing loudly - there are no giant Cicadas here - leading to poorly considered actions. That is why we practiced and rehearsed snake encounter procedures BEFORE actually encountering one.
In this case, it paid off! We came within a few feet before it made its presence known, at which point we moved away briskly as planned. End result: snake is unharmed, we are unharmed.
Rattlesnakes are often just under the drip line of bushes. This allows them to bask and avoid predation by hawks. The downside of this is you can get quite close before the snake is aware of you or you are aware of the snake. Practicing calm and stop-back away helps in moments like this.
I have not identified the species yet. This video was taken from outside of strike range (the snake never tried to strike), through the Adenostoma fasciculatum bush that had concealed the snake.