An ancient fossilized forest in Montana is reemerging 600 feet higher than the present-day tree line after spending the last 5,500 years encased in alpine tundra. But as temperatures continue to ...

The cooler temperatures shifted the tree line downslope and transformed the high mountain landscape from forest to the alpine tundra that exists today. One of the paper's authors, David McWethy ...

These trees were once part of a thriving forest, but then the cooling climate entombed them under thick layers of mountain ...