LOS ANGELES — Thirty years ago, few had heard of the Endangered Species Act (search), the new law that had been designed to help save bald eagles, alligators and California condors. 

But in its 30 years on the books, the law has emerged as a touchstone for environmentalists, and a brick wall for developers who say the law is not as much about saving whales as it is about stopping growth.

"It's the pre-eminent anti-growth act in America, the pre-eminent anti-housing, anti-construction, anti-new road law in America. That's not what it's supposed to be. It's supposed to be the pre-eminent species protection act in America," said property rights activist Laer Pearce.

"They exaggerate the dangers of the ESA to serve their own selfish desires to make a profit," said Joel Reynolds of the Environmental Defense Fund (search).

When the law was created in 1974, 109 species received protection, including the grizzly bear and the crane. Today, the law protects 1,200 species, 60 percent of which are plants.

In the last two years alone, the federal government has set aside 38 million acres of so-called critical habitat, including three parcels each the size of Rhode Island — one for a bird, one for a frog and the last for an owl.

Critics say that as a result of the act, endangered flies have blocked freeway construction, spawning salmon have brought down dams and suckerfish in Oregon have put hundreds of farmer out of work.

In California, a shrimp that thrives in mud puddles gave government nearly de facto control over private property, effectively denying owners the right to build, farm or sell their land.

"There is a lot of taking of land that happens," Pearce said, adding that hundreds of thousands of jobs have been lost in the mining, construction, logging and farming industries. "We are forced to give away a lot of our land and very rarely is anything given in return."

For six years, the Preble's jumping mouse (search) has been on the "endangered" list, stopping dozens of building projects. Last week, scientists said they made a mistake. The mouse is genetically identically to a commonly-found cousin.

"Clearly, if that mouse is listed along with 1,126 animals, critters, bugs, snakes, bats and rats and all kinds of other things that are on that list, it's just going to add to the burdens we face out West," said Sen. Ben Nighthorse Campbell, R-Colo.

Environmentalists say the snail darter (search) fish, which stopped construction of a dam in Tennessee, is not exactly the perfect poster children for the green agenda, but it is among dozens of species that would otherwise be extinct without the law. They credit ESA with performing exactly as Congress intended.

"It was grounded in the belief that we share the land with a whole host of plant and animal species and we have a moral obligation to share the land with those species," said Jay Watson of the Wilderness Society (search).

House Republicans say ESA's overhaul is long overdue. They say the bill is symbolic of the worst in big government and they want to stop the junk science, curb frivolous lawsuits and balance the rights of private property owners with rights of butterflies.

Stamping the act with a price tag in the billions of dollars and miles of red tape, the Bush administration also says should the president win a second term, it wants to amend the law.

But environmentalists say they will not budge. Even if the law is flawed, they say they don't trust this White House to rewrite it.

"I don't think we'll see a full-blown effort to tear down the Endangered Species Act. I think that would be a huge mistake," Watson said.

"One species is not endangered and that is the sacred cow," Pearce responded.

Fox News' William LaJeunesse contributed to this report.