The Endangered Species Act turns 50 this December. Often called “the pit-bull of environmental statutes,” the ESA has given federal protection to more than 2,000 animals and plants.

It has also drawn critics who claim it takes away property rights and hurts economic development. 

After half a century of recovery efforts, only a few hundred species have got delisted. On the other hand, the whole world faces a biodiversity crisis, with more than 44,000 species threatened with extinction. And the ESA has been the international model law for how to save what the world has left. 

Some of the ESA’s biggest struggles have happened in Montana, including fights over gray wolves, grizzly bears, bull trout and sage grouse. As the law reaches its 50-year anniversary, a group of reporters scanned the state to see how it’s working and what its future holds.

With me today is Rob Chaney, leader of the project, to give us a primer on 50 years of the law and what readers can expect from the reporting,