The annual cost through 2039 is estimated at $53,900.
The agency says polar bears already receive significant protection, and costs are connected to considering adverse modification of critical habitat, primarily from petroleum development.
The department in October proposed 200,541 square miles in Alaska as polar bear critical habitat. That's been revised down to 187,166 square miles to more accurately reflect U.S. boundaries for proposed sea ice habitat.
The agency will reopen a public comment period for 60 days starting Wednesday. The department plans public hearings June 15 in Anchorage and June 17 in Barrow.
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