Programs highlighting the return of monarch butterflies to Ardenwood Historic Farm in Fremont continue with slide shows and walks from 1 to 2:30 p.m. Friday and Saturday -- meet at the granary. The butterflies rest in Ardenwood's eucalyptus groves annually from about November through January as part of their multigenerational migratory life cycle. The phenomenon can be spectacular, as the butterflies cling to the trees like living shingles, occasionally taking flight in clouds of orange and black.

Ardenwood is located at 34600 Ardenwood Blvd., just north of Highway 84 in Fremont. Admission Friday and Saturday is $3 for adults and seniors, $2 for children. Parking and the butterfly programs are free. No reservations are required. For Ardenwood general information, call 888-327-2757, ext. 2797.

VISIT OHLONE VILLAGE: Nearby, Coyote Hills Regional Park plans a couple of interesting programs this weekend.

From 10 a.m. to noon and again from 1:30 to 4 p.m. Saturday, naturalist Dino Labiste will lead a half-mile walk from the park's visitor center to a reconstructed 2,000-year-old Ohlone village site. The site has a replicated pit house and sweat house. Along the way the group will see plants that provided food, medicine and tools for the Indians. Dino's program repeats on Dec. 29.

Then on Sunday, Coyote Hills will hold an open house from 11 a.m. to 3 p.m. at the visitor center, hosted by naturalist Bev Ortiz and friends. Visitors will be able to make nature-themed gift cards and stocking stuffers, sample hot, spiced apple cider and homemade treats, take tours of the visitor center and its exhibits, watch wildlife videos and go on scavenger hunts with prizes. There will be raffles at 1, 2 and 3 p.m. Gift items will be available for sale.

Coyote Hills is at 8000 Patterson Ranch Road off Paseo Padre Parkway in Fremont. There's a $5 parking fee per vehicle; the open house is free. For information, call 888-327-2757, ext. 3220.

CRAB TIME: It's crab season at Crab Cove Visitor Center in Alameda -- but just to meet, not to eat. The center will be open from 10 a.m. to 4 p.m. Friday for post-Thanksgiving activities. It's an opportunity to watch live fish and crabs up close in the center aquarium and to meet and greet the center's resident gopher snake and turtle. There will be programs throughout the day showcasing the wildlife of San Francisco Bay.

Compiling nature journals will be the focus of another Crab Cove program from 10 to 11:30 a.m. Saturday, led by supervising naturalist Sharol Nelson-Embry. Fun activities will help to sharpen your observational skills. No drawing experience required. Both programs are free. Crab Cove Visitor Center is located at 1252 McKay Ave., off Central Avenue in Alameda. Admission is free. For information, call 510-544-3187.

McLaughlin honored: It's now officially McLaughlin Eastshore State Park.

An entrance sign was unveiled in a ceremony Nov. 16 at the Berkeley Meadow area on University Avenue and Frontage Road, honoring longtime environmental activist Sylvia McLaughlin.

Speakers included Berkeley Mayor Tom Bates, Assemblymember Nancy Skinner, who authored the bill for renaming the park, Bob Cheasty and Norman La Force, of Citizens for Eastshore State Park, and Sylvia McLaughlin herself. The emcee was Robert Doyle, general manager of the East Bay Regional Park District, which manages the park on behalf of the state.

McLaughlin cofounded Save the San Francisco Bay Association in 1961 after she and other community activists became alarmed by indiscriminate filling of the bay that destroyed wildlife habitat and limited public access.

Subsequently, she cofounded Citizens for East Shore Parks along with Dwight Steele and other community volunteers. During the past 40 years, she has been active in efforts by these two organizations and the Sierra Club to preserve and protect the bay shoreline.

Eastshore State Park extends for 8½ miles along the bay front between Oakland and Richmond. It offers hiking and bicycling trails, spectacular views and areas set aside for wildlife habitat.

Ned MacKay writes a regular column about East Bay Regional Park District sites and activities. Email him at nedmackay@comcast.net.