By MATTHEW BROWNPRAY, Mont. (AP) — U.S. officials on Monday blocked new mining claims outside Yellowstone National Park as the Obama administration races in its last days to keep industry out of natural and environmentally sensitive areas. Mining claims on 30,370 acres north of the nation's first national park would be prohibited for at least two years while a long-term ban is considered, Interior Secretary Sally Jewell said during a visit to Montana's scenic Paradise Valley. Details were obtained by The Associated Press in advance of the formal announcement. Interior officials last week blocked new oil drilling in the Arctic Ocean and cancelled 25 oil and gas leases in western Colorado and 15 in northwestern Montana. Republicans and industry representatives have criticized the administration's eleventh-hour actions to limit development. They've promised to seek their reversal once Obama leaves office and Donald Trump takes charge of the White House. The latest move came after a pair of gold exploration proposals north of Yellowstone drew strong opposition from business owners, environmentalists and Montana elected officials. Local officials worry mining could hurt an economy heavily dependent on tourism and outdoor recreation. Jewell hiked a rocky trail to examine the landscape surrounding one of the mining sites, beneath the snow-capped peaks of the Absaroka Mountains. She said she hoped the temporary ban would discourage the projects' sponsors and shield Yellowstone and surrounding areas of Custer-Gallatin National Forest from development. The two-year prohibition would not explicitly block the pending proposals, both of which involve private lands. However, Jewell and other government officials said it would make large-scale mining more difficult if the projects were expanded onto public lands. "This is right on the doorstep of Yellowstone National Park, one of the most amazing places in the world," Jewell said. "It needs to be part of a larger ecosystem and this forest is part of that ecosystem. Mining will damage that. It will damage the ability of the animals to migrate. It will impact potentially the watershed. It could impact the geothermal features."