There is a rocky beach off The Sea Ranch called Tide Pool. It is where many Harbor Seal moms give birth. Steve Coffee-Smith recently photographed a pup by itself on the beach.
It is not unusual for a mother Harbor Seal to leave her sweet pup on the beach so she can fish for herself after giving birth. Never "rescue" a pup. Its mother will return. If you think you have found one in distress, the proper thing to do is call the Marine Mammal Center at 415) 289-SEAL. They will send a trained local to assess the situation.
Thanks to Steve for allowing me to share his photo with you here.