After more than 50 years as one of the country's landmark environmental laws, the Endangered Species Act has gone from one of the most popular measures before Congress to one fueling demands that it be revised, if not discarded.

The National Parks Traveler is reviewing the Endangered Species Act's work and its record, spotlighting individual species that it's protected, those that it failed, and those that it recovered.

The monthslong series comes as ESA champions worry that the push to weaken the law could consign countless animals and plants to the growing list of flora and fauna that, like the Passenger pigeon, are now found only in books and online.

The National Park System seems to be the perfect background to explore these questions, as its lands are supposedly the best preserved on the federal landscape.

I recently interviewed two wildlife advocates — Jake Li, a vice president with Defenders of Wildlife who spent time working in the Environmental Protection Agency and U.S. Fish and Wildlife Service before joining the advocacy group, and Stephanie Adams, director of wildlife at the National Parks Conservation Association.

Though the interviews were done separately, the questions were largely the same. What follows is a merging of those two conversations.

Haleakalā National Park is deceptively wonderful and rich in biodiversity. But if we're not careful, we could lose some of that biodiversity.

Located on the island of Maui in Hawaii, the first thing you notice about this national park is its towering dormant volcano, Haleakalā, which rises from sea level to more than 10,000 feet.

While many visitors simply want to head to the top of the volcano to peer into its crater or enjoy a colorful sunrise or sunset, if you take a little time to get to know this park you'll be amazed by what doesn't first come into sight. For instance, there are more than 300 plant and animal species endemic to Haleakalā — found nowhere else in the world — and many species that are being threatened or endangered with extinction.

Kurt Repanshek headed to Haleakalā this past week with Special Projects Editor Patrick Cone and Assistant Editor Rita Beamish to learn more about the park and its rare and unique species.

It's Thanksgiving Weekend, usually interpreted as a bountiful time of year when we can all sit back and be thankful. But can many who work for the National Park Service feel thankful in the wake of the staff reductions this year?

This year has been hard on the Park Service, what with the loss of roughly a quarter of the full-time workforce and questions around how the agency has long interpreted history.

But the Park Service has long struggled with its operations. Funding and staffing never seem to have met the needs of the Park Service to manage its far-flung collection of more than 400 units. We're going to explore the funding and staffing issue of the agency today with John Garder, the senior director of budget and appropriations for the National Parks Conservation Association.