Would you believe that prior to some recent efforts, the last published, scientifically verified, mountain lion in Marin County was in 1931! This charismatic animal had accumulated many fleeting sightings in local lore in the following decades, but there was sparse verifiable evidence (e.g. a clear photograph or museum specimen) that could bump the sightings up a notch to merit a place in the scientific record.
With the relatively recent increased availability of motion-activated wildlife cameras (camera traps), wary species like the mountain lion are more readily documented. I highly recommend checking out Nature of a Man and Sebastian Kennerknecht to see masterful camera trap imagery of this species.
Local biologist, Ginny Fifield, combined good, old-fashioned tracking prowess with the technology of camera traps, and did a lovely job of documenting our local mountain lions. She has been consistently documenting one local male since 2010. Her work was recently published, and is available here, including photos of this fellow and a description about what makes him unique. He is still quietly living his life here, and photos and videos of him are continually being added to http://wildfelids.smugmug.com in the "Mountain Lions in Marin County" gallery.
There are now a number of other project which have also been documenting this species locally, and I look forward to learning more about this species in the coming years.
And if news of this species occurring here is new to you, I encourage you to be excited and not concerned. Mountain lion attacks on humans are VERY rare, in the past 125 years, (since 1890) there have been only 16 verified mountain lion attacks on humans in California, and few of those were fatal. Taking a bath or owning a puppy is much more hazardous statistically. Mountain lions really prefer to avoid people and enjoy their deer dinner in peace.
For additional information on Mountain Lions in California: