March 18 at 7pm — Tune in or stream with the PBS app and online at video.lptv.org.

Yosemite Valley is a land forged in wildfire and sculpted by water; the delicate balance of these two elements is essential to the creatures and trees that call this land home. But with climates changing and temperatures rising, the Sierras are under siege. Scientists, experts and adventurers head into Yosemite to see how these global changes are affecting one of America’s greatest wildernesses.