The U.S. Department of the Interior on Monday signed off on a plan that would allow oil and gas leasing in a swath of the Arctic National Wildlife Refuge (ANWR) in Alaska, a move that invited praise from proponents but swift vows of legal action from environmentalists.

Northern Alaska Areas of Oil and Natural Gas Interest

Interior Secretary David Bernhardt said officials were acting on a directive approved by Congress in 2017. The Interior’s Bureau of Land Management (BLM) in late 2018 determined that drilling could be conducted within the refuge’s coastal plain without hurting wildlife. The refuge is home to polar bears, foxes, caribou herds and a range of other species.

Bernhardt said the plan represented a big step toward energy development in a sprawling region that had been off limits for more than 30 years despite energy...