In a 6-3 ruling, the state’s highest court agreed the state has “exclusive authority” over produced water.

The federal government is once again considering whether to use the Endangered Species Act to protect the Lesser Prairie Chicken, a finicky bird struggling to thrive in increasingly fragile western grasslands.

The most complete accounting of every one of Oklahoma’s 3,736 turbines and 58 wind farm projects.

The Oklahoma Oil & Gas Association seeks an injunction and a ruling that counties lack authority over oil-field wastewater.

Federal agency is also examining safety equipment and crew training, communication and experience.

After months of ethics scandals and investigations, the embattled Environmental Protection Agency head has resigned, the president said Thursday.

Scientists have linked thousands of earthquakes to oil-field disposal wells, but new research helps explain why much of the shaking doesn’t line up with maps of known faults.