Splintered plastic foam beer coolers lay across the Pimlico infield yesterday morning like pieces of a fractured arctic ice floe.

The crushed and soggy detritus of Saturday's Preakness revelry, accented by a sharp aroma of stale beer and suntan lotion, offered a sullen "Good morning" to a team of 150 environmentalists arriving in a cold rain.

They came with the zeal of those who would save a reckless world and believe it is still possible.

Rosemary Krussman looked at the trash and saw hope for tanagers and parrots.

Mark Verbin saw hundreds of plastic Pepsi-Cola sun visors and declared them "the wrong thing, baby, Uh-huh!"

And Jack Cover saw -- in his mind's eye -- the poisonous dart frog, a creature the color of a strawberry daiquiri.

Mr. Cover is curator of the rain forest exhibit at the National Aquarium in Baltimore and a devotee of Costa Rica, a country the size of West Virginia that is home to the dart frog and fully half the world's extant species of plant and animal life.

The Baltimore Oriole winters in Costa Rica, according to Ms. Krussman, an aviculturist at the National Aquarium in Baltimore.

Ms. Krussman and the others descended upon the infield yesterday like reverse locusts, leaving only the vegetation.

Stoop laborers in running shoes, work boots and L. L. Bean waders, they made two massive sweeps, filling hundreds of clear-plastic garbage bags with rain-soaked french fries, cookies and crab shells.

They found a working wrist watch, blankets, a pair of white socks, a red baseball cap from Applebee's Grill and Bar, car keys and a key ring marked "You're No. 1, Furlong Agency, Binghamton, N.Y.," and one bra.

Mim King found a $50 bill.

But this was not the real money.

As much as $8,000 was earned in six hours by this coalition of volunteers, most of them employees or volunteers at the Baltimore Zoo, the Washington Zoo, the Nature Conservancy and the aquarium in Baltimore.

With that money they will buy 100 acres of rain forest at $80 per acre in the La Amistad Biosphere Reserve, which straddles the Costa Rica-Panama border.

All the beer drinking, all the crab eating, all the Black-Eyed Susan swizzling, all the betting and dancing and trashing that went on less than a day earlier was being transformed into something benevolent and far-sighted, the volunteers said. Anyone who insists that beer drinking can save the world would have been reaffirmed, in a roundabout way, yesterday morning.

"You have an example of about the worst people can be -- a bunch of drunken slobs -- and then you have this kind of effort," said Rick Halperin, an employee of the Nature Conservancy in Arlington, Va.

Mr. Halperin said he imagined he was recruited because he had so much experience cleaning up after parties.

"I'm just usually more hung over," he said.

Mark Verbin, who takes care of the octopus and other animals at the aquarium, is a Baltimore native who has never been to the Preakness. He said he had always been fearful of the infield "crazies."

"I understand they have a horse race here," deadpanned one of his colleagues.

"I can't believe it was people that did this," said Ms. King a few minutes after finding the $50 bill, wadded and soaked yet still recognizable as legal tender.

Gradually, like restoration experts, she and the others cleaned away the encrustations of civilization to reveal the all-emerald painting of grassy earth below.

"Last year it seemed kind of hopeless," said Sally Grove, a fund-raiser at the Nature Conservancy. "This year, with a few more bodies, it looks like a doable thing."

The cleanup idea had sprung full blown from the Preakness partying.

In 1989, Rosemary Krussman was sitting with her husband, Eric, and friends, who kidded them about their interest in recycling.

"Hey, wouldn't you like to recycle all of this?" one of them asked.

"Yeah," she said, "as a matter of fact, we would."

The next day she called Don Rankin, president of Harry M. Stevens Maintenance Inc. of Baltimore, whose company has the cleanup contract. If she could pull together a crew of volunteers, would he let them collect the aluminum cans in 1990?

Mr. Rankin listened, with skepticism. If he let them do it, he said, they'd have to pick up the trash, too.

He warned and watched for diminution of the cleanup ardor.

"I met with them many, many times. I brought them out here to see what they were up against," he said.

He couldn't dissuade them.

Eventually, he thought, let's take a chance. He offered $2,500 for the cleanup.

He says he was amazed to learn they had gathered 167,000 cans -- worth about $2,500 from the Reynolds recycling operation.

This year, the group is receiving the same pay from Mr. Rankin and expects to earn a little more than last year from the aluminum. Ms. Krussman also enlisted Budweiser, which saw the value of a "green" project and will pay the Krussman team about $2,500, minus the cost of 500 Budweiser, Preakness cleanup volunteer T-shirts.

When only 100 volunteers showed up last year, Mr. Rankin hit the streets around the track and hired 70 men to help out.

Later, he says, he realized he had panicked. The volunteers were disciplined and well-directed. They gained speed and efficiency as the day progressed.

The 300 workers he used to hire were occasionally interested in a different kind of recycling. They had more interest in the leftover contents than they did in the cans and, typically, many would be incapacitated before the work was done.

"They would start dropping out around midmorning," he said.

"These people are pros," he said. "If anything, they're a little too thorough. They pick up the cigarette butts."

Linda Adams and Nadine Miller, both volunteers at the Baltimore Zoo, worked together yesterday. The spare plastic bags, tied around their waists, rustled as they walked.

Drivers of large, movable trash bins beeped as they backed up nearthem. Pickup trucks rolled about the infield crunching the cans as they ferried full bags to the waiting Reynolds Aluminum Co. trailers.

Ms. Adams and Ms. Miller said they found little environmental consciousness in the rest of the world.

Ms. Adams said one of her co-workers had little patience with her scolding about lizard-skin shoes.

" 'I don't care if there's no more lizards on the earth,' she said. 'I can live without lizards,' she said. It's sad," Ms. Adams said.

"People don't realize," said Ms. Miller. "Once the lizards are gone, they're gone."

The crews collected what appeared to be enough discarded lawn and beach chairs to populate Ocean City. Most of this furniture, built of aluminum and a few pieces of fabric, was recyclable. Several large cooking trays made of aluminum were collected as well.

A handsome pair of sunglasses was left hanging on a length of chain-link fence.

Virtually everything else went into the bags.

Phyllis Connor, a volunteer at the National Zoo in Washington, moved across the grass on her hands and knees, scooping cans into the bag she pulled along behind her.

"I'm a lot into saving the earth," she said. "It's kind of backbreaking work. Backs get sore, but they heal."

"You've got a pumped up group here," said Jack Cover, the rain forest curator. "The contrast between this effort and what came before is pretty incredible.

"For me, it's a religious experience," he said.