One of the more spectacular natural phenomena in the Bay Area is the arrival of monarch butterflies for their annual winter stopover on what has been described as an intergenerational relay race that can traverse a thousand miles or more.

A great place to enjoy the show is Ardenwood Historic Farm in Fremont, where colorful clouds of the insects cluster together in a eucalyptus grove. They usually start arriving in November and stay until early to mid-January. This year, they're orange and black in honor of the San Francisco Giants' World Series victory (actually they're always more or less those colors).

Naturalist Chris Garcia launches the first in a whole series of programs about the monarchs in a session from 2 to 3 p.m. Sunday, Nov. 11. Meet Chris at the Ardenwood granary for a walk to the grove to see if any butterflies have arrived, and to learn about their life cycle.

The program is free. Ardenwood Historic Farm is located at 34600 Ardenwood Blvd., just north of Highway 84 (the Dumbarton Bridge approach) in Fremont. The entrance fee on Nov 11 will be $6 for adults, $5 for seniors, and $4 for ages 4-17. Kids 3 and younger get in free, and parking is free. For more information, call 888-327-2757, ext. 2797.

  • n n

    "Women on Common Ground" is naturalist Katie Colbert's program for women who enjoy the outdoors but have concerns for personal safety. Katie will lead an easy four-mile hike through the oak savannas of Morgan Territory Regional Preserve east of Mount Diablo from 10 a.m. to 2 p.m. Saturday, Nov. 17.

    The hike is free, but registration is required. Call 888-327-2757 and refer to program 30702. For hike information, call 510-544-3243.

  • n n

    There's a story, often tragic, behind every grave marker in Rose Hill Cemetery at Black Diamond Mines Regional Preserve in Antioch.

    Naturalist Eddie Willis will lead a walk to the cemetery from 10 a.m. to noon Sunday, Nov. 11, telling stories of the miners and their families who are buried there.

    The hike is free. Meet Eddie at the parking lot at the end of Somersville Road, four miles south of Highway 4 in Antioch. Black Diamond Mines has a parking fee of $5 per vehicle when the kiosk is staffed. For information, call 888-327-2757, ext. 2750.

  • n n

    This is a good time of year to visit Vasco Caves Regional Preserve south of Brentwood, when the grass is starting to turn green and the vernal pools are beginning to fill with water. Besides the spectacular rock outcrops and Native American pictographs, there's a chance to see eagles and other raptors.

    Vasco Caves is accessible only by guided tours, which are restricted to ages 10 and older, and cost $30 per person ($34 for nondistrict residents).

    There may still be room on tours scheduled for 9 a.m. to 2 p.m. Dec. 2 and Dec. 15. For information and registration, call 888-327-2757. For Dec. 2, refer to program number 30708. For Dec. 15, it's 30710.

  • n n

    For a climb to a great view, join naturalist Trent Pearce on a three-mile hike from 11 a.m. to 2 p.m. Sunday, Nov. 11, to the top of Wildcat Peak at the Tilden Nature Area in Berkeley.

    There's a 360-degree panorama encompassing Mount Diablo, Mount Tamalpais, San Francisco Bay and the Golden Gate. Trent will talk about the area's natural and cultural history along the way. Bring lunch.

    The hike is free. Meet at the Environmental Education Center at the north end of Tilden's Central Park Drive. Bring lunch. For information, call 510-544-2233.

  • n n

    Over at Sunol Regional Wilderness there still may be time to register for a "Canine Caper" walk with your favorite four-legged friend up to the top of Mission Peak.

    This is a steep, strenuous hike from 9 a.m. to 3 p.m. Saturday, Nov. 10, led by naturalist Kristina Parkison. It's best for folks ages 8 and older. Homemade dog snacks will be provided. Rain cancels.

    The hike is free. Sunol has a parking fee of $5 per vehicle. For information and registration, call 888-327-2757. Select option 2 and refer to program number 30734.

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