Federal authorities must apply more scrutiny to potential impacts on greater sage grouse across hundreds of oil and natural gas leases in Wyoming and Montana before authorizing new drilling, a federal judge in Idaho has ruled.

sage grouse

Magistrate Judge Ronald Bush ruled that the Interior Department’s Bureau of Land Management (BLM), under former President Trump, failed to adequately assess potential impacts of 605 leases on the birds.

The leases span more than 400,000 acres across the two states that are habitat for greater sage grouse, a ground-dwelling bird whose numbers have dwindled in recent years amid development in the West. Bush cited federal reports that estimate the birds’ population at less than 10% of past peaks, and he said the species occupies only about half its...