This is 99% Invisible. I'm Roman Mars.

When the Endangered Species Act passed in 1973, it was a bipartisan home run.

The Act established protections for plants and animals on the endangered and threatened species lists.

And across the aisle, everyone seemed to agree that it would be bad for a bunch of species to go extinct.

When the act went to a vote, not a single senator voted against it.

Flash for just over 50 years, and the story could not be more different.

Today, communities across the nation are fighting over the ESA,

and a whole legal specialty has sprung up around how to use it

and how to fight it.

The 1973 Endangered Species Act is the subject of an incredible new podcast called The Wide Open.

The series is hosted by Nick Mott.

We're going to be playing an episode from The Wide Open, but before that, I had a conversation with Nick about his new series and the controversial law at its center.

Hi, Nick. So you host a podcast called The Wide Open. Its first season is about the Endangered Species Act of 1973, which gave federal protection to plants and animals listed as either threatened or endangered.

And I just want to start from the beginning.

Like, what made you want to do a story about the Endangered Species Act specifically?

Like, there are lots of different stories you can cover about the environment.

What got you interested in this one?

You know, I feel like the Endangered Species Act has kind of been following me around for years.

I grew up in Kansas in the suburbs where, like, it wasn't a wild place at all.

It turns out now there's certainly endangered species there, but I didn't know about them.

But after I went to college, I moved out west to do conservation work. So things like

building trails, you know, cutting down non-native trees to restore habitat for sage grouse, which is

...