Over the past two years, the Trump administration has relentlessly moved to relax or repeal major environmental and safety rules for the fossil fuels industry to further its energy goals. Each change was reported by news outlets, including the AP. But Billings, Montana, correspondent and environment team member Matthew Brown decided to look more deeply into the highly touted savings to industry as well as the societal costs.

For months, Brown painstakingly examined 11 major rules targeted by Trump’s administration. Using the government’s own detailed projections required by executive order, he sought to find how much businesses would benefit and the public would be harmed by the widespread deregulation.

Wading through many thousands of pages of government documents and researching each rule’s history, Brown built a spreadsheet to summarize what he found. He identified $11.6 billion in potential savings for companies that produce, use and transport fossil fuels. Billions of dollars more are expected to come from the freeze of vehicle fuel efficiency standards that will produce a 79 billion-gallon hike in fuel consumption.

But Brown also discovered that those savings will come at a steep cost, including more premature deaths and illnesses from air pollution, increased greenhouse gas emissions and additional derailments of trains carrying explosive fuels.

He was able to authoritatively illustrate sweeping impacts such as: up to 1,400 premature deaths from the pending repeal of a rule for cutting coal plant pollution; an increase of greenhouse gas emissions over the next decade that equates to the annual emissions from about 200 million vehicles; increased water contamination from fracking; and fewer safety checks to avoid offshore oil spills like the 2010 Gulf of Mexico disaster.

To round out reporting on such complex rules, Brown reached out to industry experts and former government officials to check his methodology and to get comment and interpretation of the AP analysis.

Through use of meticulously reported examples, he was able to conclude that the administration has tried to support the rules changes by emphasizing, and sometimes exaggerating, economic gains while minimizing negative impacts. While researching the story, he also discovered that the administration mistakenly understated by $171 million the societal benefits of improving the brakes of oil trains to avoid derailments.

His Only on AP was accompanied by photos and a glance describing each of the 11 rules and the impacts. The package ran on front pages of at least 16 newspapers, including many in the oil and gas states of Texas and California, and on numerous web sites. The Washington Post displayed both the main-bar and glance.

For in-depth reporting and comprehensive accounting of the administration’s actions on important environmental and safety issues, Brown wins this week’s Best of the States.