The ESA has been in the Trump administration’s crosshairs since January. Rigorous regulations, the administration has argued, “shackle the development” of the nation’s energy resources and hinder “energy domination.” Agency guidance documents issued this year order federal agencies to rewrite ESA rules in ways that would streamline fossil fuel projects and circumvent environmental review processes.

Conservatives such as Burgum paint the law as broken, with rigid rules that do little to advance recovery. Conservation scientists and legal experts say the law is sound but has been undermined by inadequate funding and wavering political support.

“The issue has been that Congress has not been willing to devote the resources necessary to implement the law the way it was intended,” Mergen said. “We continue to wait until species are in dire straits before we protect them. That makes recovery far more difficult and expensive.”

In fact, experts say, the ESA has kept mass extinctions at bay. Of the nearly 2,000 species listed since 1973, only 26 have gone extinct while under federal protection. At least 47 more are believed to have disappeared in the United States while awaiting a listing.

“The ESA works more like a critical care unit than a hotel,” Wilcove said. “It’s as though we built a great hospital but never funded enough doctors or equipment.”

No ESA success story is as well known as that of the bald eagle. Once a staple of American iconography, the bird was felled in the 1960s by the widespread use of the pesticide DDT and development of its prime habitat. By the time DDT was banned and the eagle gained ESA protections in 1978, just a few hundred pairs nested in the lower 48 states. After several decades of conservation efforts, the bird was removed from the endangered list in 2007, with nearly 10,000 pairs counted across the nation.

The grizzly bear, American alligator, American paddlefish, peregrine falcon, and Steller sea lion have also rebounded in number thanks to ESA protections.

The law’s protections for imperiled species apply to private and public land alike. This has long been a source of tension: More than two-thirds of listed species rely on private lands for their survival, and about one in 10 exist there exclusively.

“You essentially cannot change the condition of that land without a permit,” Adler said. “Your ability to use that land is going to be limited and you can be prosecuted. That discourages landowners from cooperating.”

Conservation rules have created so-called perverse incentives, research has found. In one study on the ESA and red-cockaded woodpeckers, for example, trees were harvested earlier on tracts where the bird was found, presumably to preclude federal restrictions on habitat use.

To incentivize private cooperation, Congress added tax breaks and conservation easements in the mid-2000s to provide financial benefits for landowners that voluntarily protect habitats. A range of conservation groups have bemoaned the slow decline of these and other voluntary programs in recent years.

The Endangered Species Act, once widely supported by both political parties, is now one of the most litigated environmental laws in U.S. history. Lawsuits challenging the ESA have cropped up in every administration, only to be blocked when a new party takes control.

Today, the law’s fate has conservationists particularly worried: The Trump administration’s aggressive push to roll back protections could establish precedent in a conservative-leaning Supreme Court. In the meantime, threats such as climate change and habitat loss have put ever more species in crisis, including many in North Dakota.

Harvard Law School’s Andrew Mergen has spent decades litigating ESA cases. But he said he’s long been convinced that the law’s problems stem not from overregulation but underfunding.

“The law has prevented extinctions,” he said. “The real challenge is committing enough funding and political will to help species recover, not dismantling the protections that keep them alive.”

The recent flurry of political attacks on the ESA are a far cry from its origins in bipartisan support. But conservationists have reason to hope that, even in the current climate, species can still be saved. In July, the U.S. Fish and Wildlife Service announced that the Roanoke logperch, a small freshwater fish native to the mountains of Virginia, has recovered enough to be delisted.

Conservation groups are pushing back against claims by Burgum and others that delisting represents the ESA’s decline. The Roanoke logperch’s recovery, they note, took more than three decades of dam removals, wetland restorations, and expensive reintroduction efforts.

“These projects were initiated and implemented years before the Trump administration,” Wilcove said.

“The optimistic part,” he added, “is that we know how to save species when we invest in them. The question is whether we’ll make that commitment.”