There's good news at Tilden Nature Area in the Berkeley hills. A sewer upgrade project that limited access to Tilden's Environmental Education Center and Little Farm has been completed, and Central Park Drive has reopened.

So now you don't have to detour. You can once again get to the center and farm by parking at the north end of Central Park Drive and walking a short distance. The Little Farm animals that were moved during construction are back home again, and normal farm activities have resumed.

Besides upgrading the sewer system, the project involved renovating the restrooms, repainting the center interior and making the center and its toilets more disabled-accessible.

The center is open from 10 a.m. to 4:30 p.m. Tuesdays through Sundays. The Little Farm is open daily. For information, call 510-544-2233. And there's more. Farther up Central Park Drive, Tilden's vintage Herschell-Spillman merry-go-round has reopened under new management. Hours of operation are 11 a.m. to 6 p.m. daily through Sept. 1. Tickets can be purchased at the ride.

As long as we're talking about Tilden, there's a snake program at the center from 2 to 3 p.m. July 20, led by interpretive student aide Sam Fuller. It's a chance to see a rattlesnake under safe conditions, learn how snakes serve a beneficial purpose in the wild and find out how to coexist with them.

If you can't make the Tilden snake program, you can meet a live gopher snake anytime between 10:30 a.m. and 1:30 p.m. July 19 at Lake Temescal in Oakland.

Naturalist Michael Charnofsky will preside. Meet him at Temescal's south lawn area, which is accessed via the park's Broadway Terrace entrance just west of Highway 13. For information, call 510-544-3187.

And there's what's described as a "somewhat strenuous" 5-mile hike starting at 9:30 a.m. July 23 from Tilden's Padre Picnic Area up to Vollmer Peak. Padre Picnic Area is located on South Park Drive between Wildcat Canyon Road and Grizzly Peak Boulevard. It's part of the Wednesday Walkers series, and everyone's welcome. For information, call 510-544-3282.

I've climbed that hill -- the description is accurate.

Redwood Regional: Hikes for Tykes, a series of free, 1-mile nature walks for young children accompanied by parents, will convene at Redwood Regional Park on July 22. Led by naturalist Sara Fetterly, the walk is from 10:30 to 11:30 a.m. Meet at the Canyon Meadow staging area. To get there turn into the park entrance on Redwood Road about 2 miles east of Skyline Boulevard, and drive all the way to the end. For information, call 510-544-3187.

Crab Cove: There will be tales of whales during Family Nature Fun Time from 2 to 2:30 p.m. July 19 and 20 at Crab Cove Visitor Center in Alameda. There's a different program each weekend, after which it's fish-feeding time from 3 to 3:30 p.m. at the visitor center aquarium.

Crab Cove is at 1252 McKay Ave. off Central Avenue in Alameda. For information on Crab Cove programs, call 510-544-3187.

COYOTE HILLS: And you can develop a flair for fire making by joining in a program from 1:30 to 4 p.m. July 26 at Coyote Hills Regional Park in Fremont, led by naturalist Dino Labiste. Dino will show how fire can be made using a hand drill and bow drill, techniques that are thousands of years old. It's harder than it looks.

Dino's program is for ages 16 and older. It's free, but registration is required. To register, call 888-327-2757. Select option 2 and refer to program number 6348.

CROCKETT HILLS: The Over-the-Hills Gang will explore Crockett Hills near Crockett in a hike from 10 a.m. to 12:30 p.m. July 22 led by naturalist Gail Broesder. The gang consists of hikers 55 years and older who enjoy nature study, history, fitness and fun.

Meet at the Crockett Hills staging area, which is on Crockett Boulevard between Pomona Street and Cummings Skyway. For information, call 510-544-2233.

DELTA DISCOVERIES: At Big Break Regional Shoreline in Oakley, there are ongoing Delta Discoveries programs from 11 a.m. to 2 p.m. every Saturday and Sunday in July and August, with lots of hands-on arts and crafts activities.

And from 9 to 10 a.m. every Saturday and Sunday you can help the naturalist staff test to check Delta water quality.

From 2 to 3 p.m. July 19, the naturalists will head a "walk on the wild side" scavenger hunt to explore the various Delta animal habitats. Big Break Visitor Center is at 69 Big Break Road off Main Street in Oakley. For information, call 888-327-2757, ext. 3050.

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