I am not exactly sure what kind of squirrel this is, but I suspect that it is a California Ground Squirrel (Spermophilus beecheyi). These guys seem to be exploiting a new habitat, as humans tend to give them peanuts along the rocky coast area. They seem to live under the rubble provided to shore up the shoreline.
This is not a new photo, but one that I took a couple of weeks ago on my last collecting trip. I am currently on a collecting trip in Washington and Oregon, so expect new photos from that when I get back!