WATCH: Nat Geo’s ‘Moment on the Earth’ captures bears in Alaska’s Katmai National Park

This “Moment on the Earth,” from National Geographic’s National Parks USA, spotlights bears in Alaska’s Katmai National Park, a safe haven for mothers raising cubs.

​This “Moment on the Earth,” from National Geographic’s National Parks USA, spotlights bears in Alaska’s Katmai National Park, a safe haven for mothers raising cubs.  GMA This “Moment on the Earth,” from National Geographic’s National Parks USA, spotlights bears in Alaska’s Katmai National Park, a safe haven for mothers raising cubs.