UPDATE (Tuesday, 8 pm) on The Search for Silvia

Members of the Monday and Tuesday Meandering in Marin hiking groups met Tuesday afternoon at the home of Wendy and Bill Dreskin.  Facts related to Silvia Lange's disappearance on Sunday at Point Reyes National Seashore are unclear, but here is what is known or supposed to be true:

• Silvia bought books at the Bear Valley Visitor Center at the Seashore about 11:30 a.m. Sunday morning.
• Hettie, Silvia's youngest Yellow Lab, was seen about 12:30 pm.  Accounts vary as to whether the dog's leash was caught in some rocks along Point Reyes Beach's north end, tied to a rock, or whether Hettie was running loose in the area.
• Another park visitor apparently looked for, but was unable to find Hettie's owner, and took the dog to Seashore headquarters or the Visitor Center at Bear Valley.  
• Assuming that it would have taken a half hour or more for her to drive from the Visitor Center to the beach, Silvia would have been on the beach for a half-hour ore less before Hettie was discovered and Silvia went missing.
• There appear to be two possible explanations for Silvia's disappearance:  1) Sheer was struck by a wave and carried out to sea by a rip current; 2) a person or persons unknown abducted her.
• Meanderers who know Silvia assume that she would have stayed well clear of the surf unless Hettie had entered it and Silvia was compelled to follow to rescue the dog.  Surfers using the beach at about that time were interviewed, but did not see Silvia.
• The disappearance of a 37 year-old woman from Alameda at McClure's Beach (a few miles to the north of where Silvia was) approximately two weeks ago remains unsolved.
• Park officials have as yet been unable to determine whether Silvia and the Alameda woman were swept into the ocean, or taken from the park against their will.
• The search for Silvia continued today without results.

News broadcasts by Bay Area TV stations at 6 pm provided no further information on the efforts to locate Silvia.  The latest Marin-IJ report was posted on its Web site just after 7 pm Tuesday evening.