Kids want to put Montana on trial for unhealthy climate policies

For her birthday every October, Grace Gibson-Snyder and her family explore the Lamar Valley just inside the northern border of Yellowstone National Park.

Carved long ago by meandering glaciers, the valley is home to bison and bald eagles, grizzly bears and gray wolves. Gibson-Snyder has seen them all. She calls it "my favorite place."

"I know how special it is to have this in my life," said Gibson-Snyder, an 18-year-old from Missoula, Montana, "and I don't want it to go away."