Hiking opportunities abound, and free, guided nature walks for all ages are scheduled in the East Bay Regional Parks during the coming week. To mention a few of the times and places:

Sibley Regional Preserve, Oakland's backyard volcano, is the destination for a nature hike from 9 a.m. to 1 p.m. Friday, led by naturalist "Trail Gail" Broesder. Meet at the park's staging area on Skyline Boulevard just east of the intersection with Grizzly Peak Boulevard. The hike is on, rain or shine. Bring water and a snack to share

Naturalist Sara Fetterly will lead one of her Saturday Strolls from 10 a.m. to noon this weekend at Redwood Regional Park in Oakland. This is a bit more than a stroll -- it's a moderate, 4.25-mile loop through the redwoods on the Golden Spike and West Ridge trails. Meet at the Big Bear Gate staging area, which is on the right side of Redwood Road about 2 miles east down the hill from the intersection with Skyline Boulevard.

Bird watchers can enjoy a level, 2-mile walk from 9 a.m. to noon Sunday at Miller/Knox Regional Shoreline in Point Richmond, led by naturalist Anthony Fisher. All levels of bird expertise are welcome. There's a variety of bird habitat, which should make for good sightings. If you go, remember that the tunnel from Point Richmond is closed for repairs, so you have to detour via Western or Seacliff drives. Then meet in the parking lot on the Bay side of Dornan Drive, closest to the tunnel.

At Black Diamond Mines Regional Preserve in Antioch, naturalist Eddie Willis will lead a hike from 10 a.m. to 12:30 p.m. Sunday in search of early wildflowers along the Chaparral Loop and Manhattan Canyon trails. Eddie's hike is geared for ages 8 and older. Meet him at the uppermost parking lot on Somersville Road, 5 miles south of Highway 4.

Also on Sunday, interpretive student aide Morgan Rani Evans will host a program from 2 to 3 p.m. at Tilden Nature Area in Berkeley to discuss the vital role oak trees play in the wildland environment. Meet Morgan at the Environmental Education Center, located at the north end of Tilden's Central Park Drive.

The Over-the-Hills Gang, an informal but intrepid group of hikers ages 55 and older, will explore Point Pinole Regional Shoreline in Richmond during a hike from 10 a.m. to 12:30 p.m. Tuesday. The guide is Dave Zuckermann, Tilden's supervising naturalist. Meet at the parking lot off Giant Highway in Richmond.

And the Wednesday Walkers, another informal group to which all are welcome, has scheduled a flat and easy 4-mile hike at Quarry Lakes Regional Recreation Area in Fremont starting at 9:30 a.m. Wednesday, led by naturalist Erica Herron. The park entrance is on Quarry Lakes Drive/Isherwood Way. Meet by the park pavilions.

For information on the programs at Sibley, Miller/Knox, Tilden and Point Pinole, call 510-544-2233. For information on the Redwood Park program, call 510-544-3187. For the Black Diamond flower walk, the number is 888-327-2757, ext. 2750, and for Quarry Lakes it's 510-544-3282.

SKYLINE TRAIL: While you're exploring the regional parks, check out the East Bay Skyline National Recreation Trail, which is also part of the Bay Area Ridge Trail. Starting at the Alvarado Area of Wildcat Canyon Regional Park in Richmond, the Skyline Trail extends for 30 miles through the East Bay hills, linking six regional parks as it goes. Besides Wildcat, it passes through Tilden, Sibley, Huckleberry, Redwood and Anthony Chabot regional parklands. In a way, it's a walk through history, because these parks and Lake Temescal were the first ones opened to the public in the years after the district was established in 1934.

The park district has no current map that shows the Skyline Recreational Trail in its entirety. However, the route is marked on the individual maps of each park through which it passes. And signposts on the trail itself bear the distinctive Skyline Trail and Bay Area Ridge Trail decals. If you go online and search for "East Bay Skyline National Recreation Trail," there are numerous websites with information. You can download individual park maps from the park district website, www.ebparks.org.

There are many beauty spots along the way. My personal favorites are San Pablo Ridge in Wildcat and Tilden, and the forest of Redwood Regional Park. Recently, some friends and I hiked up the Belgum Trail from Alvarado Area to the ridge top. There's no denying that it's a long uphill trek, but on a clear day the views from the top are nothing short of spectacular. Serenaded by a coyote chorus, we saw the sun rise over Mt. Diablo, bathing San Francisco, the Golden Gate and Mt. Tamalpais with morning light. The panorama reminded us how lucky we are to live in one of the most beautiful places in the world, with access to so many public lands preserved for us to enjoy.

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

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