The latest front in the war against drilling for oil in Alaska’s rugged wildlife refuge isn’t Washington — it’s Wall Street. Activists trying to keep rigs out of the Arctic National Wildlife Refuge are now focused on choking off the flow of money needed to exploit the reserve. As big as South Carolina, it is home to caribou and grizzlies — and possibly billions of barrels of oil.

The strategy is paying off. Morgan Stanley just ruled out financing Arctic oil and gas development, becoming the fifth major U.S. bank to announce it will no longer support drilling in one of the fastest-warming places on the globe. That followed similar moves from Citigroup Inc. earlier this week and from Goldman Sachs Group Inc.JPMorgan Chase & Co. and Wells Fargo & Co. in the space of four months. Bank of America Corp. is the only major U.S. holdout.

Lending restrictions now pose another obstacle to oil companies hunting for the next big U.S. discovery, particularly after an epic collapse in prices, declining demand tied to coronavirus and a mounting glut of crude. The Interior Department is preparing to sell drilling rights in the 1.56-million-acre coastal plain of the Arctic refuge. However, remote conditions and limited infrastructure in northeast Alaska ratchet up the cost of finding and developing crude there, making it even less attractive to oil producers in this economy.