We are considering doing our February "hike" at Ano Nuevo State Reserve (southern San Mateo county coast, about 1 hr., 40 mins from Pleasanton). This is a guided walk mostly over boardwalk along a beach that serves as an elephant seal colony. In February, hundreds of these seals crowd the beaches...when I went a few years ago, there were many new-born seal pups to see, and it felt like walking through a National Geographic Special (way better than 3D, HD television!).
Here are a couple of links to explore. The cost is $7 per person; tours consist of a max of 20 people - but depart a few times an hour. We need to buy tickets soon - so we will have a sign up sheet tomorrow. We may be able to spread out over two weekends - we're considering the weekends of 2/12-2/13 or 2/19-2/20. Note: Monday 2/14 and Monday 2/21 are PUSD holidays.
http://anonuevo.reserveamerica.com/tourDetails.do?contractCode=CA&tourId=24862&cat=1
http://www.parks.ca.gov/?page_id=523
Contact Raj P to sign up!