On April 22, 1970, we celebrated the first Earth Day. The environmental movement was underway, and on college campuses across the country interest in the environment rivaled that of opposition to the Vietnam War.

Over the last 38 years, enthusiasm for Earth Day has ebbed and flowed. Topics such as air and water quality, toxic wastes, endangered species and biodiversity have taken turns making headlines, but concerns about energy and its costs strike closest to home.

As the cost of a barrel of oil exceeds $100 and the price of gasoline and diesel exceeds $3.50 per gallon, Americans may finally be ready for a real green revolution. Western Pennsylvania seems ready, judging by the myriad events taking place in celebration of Earth Day 2008. Many of the activities, scheduled over the next couple of weeks, provide more excuses to get out and get physical.

As a Pittsburgh marketing executive, Boris Weinstein came up with former Mayor Pete Flaherty's "For Pete's Sake" cleanup campaign. His agency did those anti-litter "pig in the living room" TV spots for former Mayor Richard Caliguiri.

Now 76 and retired, Weinstein hasn't given up on what he calls his "passion for cleaning up litter." His volunteer group, Citizens Against Litter (www.citizensagainstlitter.org) was instrumental in coordinating a regional neighborhood cleanup campaign.

"When I retired, I started thinking small," he said. "I thought if I can create a program to eliminate litter in one community, it can be replicated in other communities."

After coordinating cleanups in Shadyside, he moved on to Squirrel Hill, Homewood and beyond. This year more than 185 communities in Pittsburgh and across Southwest Pennsylvania will participate in the Redd Up Weekend April 18-20. The anti-litter campaign kicks off with the annual Stash the Trash event on April 18. Pittsburgh public, private and parochial schools have been invited to participate. The activity is expected to attract thousands, getting people outside and doing something active that's also good for the Earth.

"It's a matter of bending and picking up," said Weinstein. "You can't do it drinking coffee at the meeting place. I do it with the aid of a picker-upper, which is easier on my back."

Redd Up Weekend volunteers are advised to bring gloves and plastic bags.

"Use those plastic shopping bags. Large trash bags, you can't lug around," he said. "In two or three hours they'll cover some ground, but I don't think they'll walk five miles. If people get a couple of miles in, with all the bending and picking up, they're getting some good exercise.

"I have circulation problems and the doctor says walk, walk walk. Well, it gets pretty boring just walking. I pick up while I walk and look over my shoulder and it's clean, clean, clean."

While communities are patrolling their own spaces, the Frick Environmental Center in Squirrel Hill will encourage families to get back to nature.

Most of the park's April 19 programming involves interacting with nature: a bird walk, invasive species removal, craft projects using natural materials and flower bed planting.

"We want people to get out and experience the outdoors," said park naturalist Phil Costanzo. "It brings them more in touch with the Earth than sitting in a classroom."

The Frick Park activities are designed to capitalize on public interest in Earth Day while improving park amenities and teaching vital lessons about caring for the land.

"Any time you can promote a better environment, a better place to live, it's an important message," said Costanzo. "However you bring it out -- from talking about car efficiency to actually having people steward the environment -- those are all ways of getting people to interact with the environment."

If you're looking for more than community involvement and elbow grease -- if you'd like to celebrate the Earth by getting outside and hiking, breathing fresh air and enjoying nature -- mark April 27 on your calendar.

The Total Ecology Extravaganza at Enlow Fork Natural Area is a free, all-day event at State Game Land 302 in Greene County.

Formal activities begin at 8 a.m. with a bird walk led by local experts Ralph Bell and Marjorie Howard. Stay near the front of the group to pick their brains and learn the songs of spring migrants such as Baltimore orioles, indigo buntings and house wrens. And bring the kids.

At 10:30 a.m. Bonnie Isaak, president of the Western Pennsylvania Botanical Society, will lead a spring wildflower walk. Bring a camera and take home images of several species of trillium, phlox, jack-in-the-pulpit, Virginia bluebells, spring beauties and many more.

But the stars of Enlow Fork are the Blue-eyed Marys. You'll recognize this lovely ground cover by its blue lower lips and white upper lips. Thousands of them carpet hillsides and open woods of the game lands' 2,000-plus acres. This native annual develops from seeds dropped the previous year. Often the seeds germinate in the fall, and the plant grows to maturity in the spring.

Once upon a time, the Enlow Fork event was known as the Spring Fling. No promises, but last year my Total Ecology Extravaganza species list included scarlet tanagers, rose-breasted grosbeaks, yellow-billed cuckoos, eastern bluebirds, yellow warblers, common yellowthroats, ovenbirds, pileated woodpeckers, wood thrushes and Acadian flycatchers.

Just bring binoculars and stay close to trip leaders for a day to remember.

For more information on the events at Enlow Fork, contact Larry Helgerman at bobolink1@earthlink.net.