Enormously popular when it cleared Congress 50 years ago, the Endangered Species Act has become one of the most controversial U.S. environmental protection laws. Environment team reporter John Flesher teamed with Detroit video journalist Mike Householder and photographer Paul Sancya for an in-depth look at the measure’s record and prospects when many question whether it will survive another half-century.

Flesher delved into government statistics and scientific reports and consulted biologists, environmental law experts and advocacy groups while monitoring congressional votes and agency actions. He and Billings, Montana-based reporter Matthew Brown landed exclusive interviews with Interior Secretary Deb Haaland, whose department administers the act, and top aides. Flesher’s reporting found that while more than 99% of listed animals and plants have survived, relatively few have fully recovered; and funding shortages are preventing hundreds of others in decline from being evaluated for protection.

To illustrate the act’s challenges, Flesher, Householder and Sancya joined two biologists on a field expedition in southern Michigan, where the scientists stretched nets across a river in search of two endangered bat species once plentiful in the area. Hours of waiting yielded eight bats, which the experts studied and released, but none of the types they sought — a grim signal. Householder produced an engaging video featuring the scientists, while Sancya compiled a gallery of 18 photos including the captured bats and other iconic species.