Itinerary: Earth Day

America’s modern environmental movement was born April 22, 1970, when 20 million people demonstrated on behalf of protecting the Earth. The activism that followed led to the creation of the Environmental Protection Agency and the passage of the Clean Air, Clean Water and Endangered Species acts.

This weekend marks the 30th anniversary of Earth Day. Events will be held across Los Angeles County (and the nation) to draw attention to preserving the world we live in. It’s expected to be one of the largest environmental events in history.

Friday

Watch a small town tackle environmental issues on the big screen. The film “Family Tree” opens at the Landmark Westside Pavilion Cinemas (10800 W. Pico Blvd., West Los Angeles. [310] 475-0202) and the Regent Showcase (614 N. La Brea Ave., Los Angeles. [323] 934-2944). The movie depicts the life of a 9-year-old boy who goes up against his father to save the town’s old oak tree.

Saturday

Start your day with Los Angeles County’s EarthFaire 2000 (Exposition Park, on the lawn in front of the Natural History Museum, between Exposition Boulevard and Figueroa Street. 11 a.m.-7 p.m. Free. [800] HEAL BAY). The event begins at 8:30 a.m. with a pollution-free procession from Pershing Square (5th and Hill streets, downtown L.A.) to Exposition Park featuring alternative-fuel and human-powered transportation. It continues at Exposition Park with interactive exhibits that demonstrate everyday things you can do to protect the planet. The finale concert from 3:30-7:30 p.m. features Sophie B. Hawkins, Chris Perez and Beth Hart.

Learn how to reduce your residential yard waste with a Smart Gardening Workshop at Flournoy Magnet School in Watts (1630 E. 111th St., Los Angeles. [888] CLEAN LA). The Los Angeles County Department of Public Works’ program teaches participants about grass recycling, backyard composting and low-water gardening. Classes are aimed at reducing waste and maximizing natural resources.

If you’re farther south, head to Manhattan Beach for the ninth annual Earth Day Celebration and Concert in Polliwog Park (Manhattan Beach and Aviation boulevards. 11 a.m.-4 p.m. Free. [310] 318-6642). The event features live music by the pop-rock group the Tories in addition to eco-friendly activities, food and fun.

Or drop by the Long Beach Aquarium of the Pacific (100 Aquarium Way, Long Beach. $14.95; ages 3 to 11, $7.95; seniors, $11.95. 9 a.m. to 6 p.m. [562] 951-1694), where you can learn how to prevent ocean pollution through hands-on activities and conservation displays. Go fishing for trash, learn about threats to the world’s coral reefs, make an ocean in a jar, or visit the touch tanks.

Watch as Antenna Theater turns Santa Monica Beach, north of the pier, into a Zen garden. Its millennium-inspired interactive beach sculpture “.:.sands.:.of.:.time.:.” includes sand sculptures and drawings that span the length of five football fields. Participants view the creations while listening to a headset that narrates the evolution of the universe. 1:30-7 p.m. Free.

Sunday

Get in touch with Mother Earth with a hike or mountain bike ride in Topanga State Park (20825 Entrada Road. [310] 455-2465). Clearly marked trails take you through the Santa Monica Mountains, where you’ll see horses trotting along rocky trails, purple and yellow wildflowers, and you might get a spectacular view of the Pacific Ocean. Parking: $5. Open daily from sunrise to sunset.