When it comes to environmental groups, extremism pays. A review of the tax forms filed by many of the most active — and radical — groups operating in the Western U.S. shows that the top 10 groups received nearly $1 billion in contributions and legal fees.

That’s billion, with a “B.”

If they wanted to, those groups could fully fund the U.S. Fish and Wildlife Service’s endangered species programs — for five years.

Instead, they go for the money. They snipe at the federal government and, as importantly, at farmers and ranchers. Many prefer to drag their targets into court instead of seeking compromises that would help species and allow farmers, ranchers and others to stay in business.

In fact, the litigation precludes such compromises.

“When you’re litigating something, you almost can’t really talk to anyone,” said Don Stuart, former American Farmland Trust Pacific Northwest director. He wrote a book about the clashes over the ESA.

The reasons for suing the government and ranchers are clear. Many environmental groups don’t like animal agriculture. They want a vegetarian lifestyle. And they don’t like large-scale farming. Anything they can do to get rid of ranching and large farms would be a feather in their cap.

But there’s more to it. Environmental organizations cannot raise money if they solve problems. They must make sure the problem remains, or they can’t produce the glossy ads and pamphlets and hold fund-raisers.

You’ll never hear an environmental group announce to its donors, “Well, we’ve solved that problem. Thanks for your help, and we’re now going to dissolve the group.”

Environmental groups need a perceived problem — preferably one that’s “getting worse and that, through your donations, we can make a difference.”

Here’s the format they use:

“The (insert an animal, fish or insect) needs your help. We will fight to save the (insert an animal, fish or insect). With your donation, we can save the (insert an animal, fish or insect) for our children and generations to come.”

The environmental groups came up with this formula decades ago, when Congress wrote the Endangered Species Act and President Richard Nixon signed it into law.

With its deadlines and protection not of species but of specific populations, the ESA was a gift to the environmental movement.

Suddenly, these groups had an open playing field to petition the government to protect local populations of salmon, smelt, wolves, owls, grouse and other critters as though they were the last of the species.

Take, for example, the gray wolf, which is protected as “endangered” in parts of the Lower 48 despite the fact that just over the border in Canada there are more than 50,000 — and about 10,000 in British Columbia alone. Yet under the ESA, American wildlife managers must protect wolves as though they are the last of a breed.

The ESA is the blunt instrument that turned environmentalism into big business. If the U.S. Fish and Wildlife Service or any other federal agency does not follow the letter of this poorly written law environmental groups drag them into court.

The result is a payday for the environmental group, if they can convince a judge that the agency missed a deadline or failed to meet some other requirement.

For environmental groups, it’s a great deal. Groups spend all of their time suing the government and other bystanders. Instead of solving problems, they make sure the problems continue.

It’s like shooting fish in a barrel that the ESA provided.