Ecologist Chris Morgan observes a family of black bears that live in Anchorage, Alaska's urban mecca. Watch video from Bears of the Last Frontier: The Road North.

Chris Morgan sets up camp alongside the largest concentration of grizzlies in the world. Hour one of the three-part Bears of the Last Frontier series.

A brown bear mother and her cubs come within feet of ecologist and bear biologist Chris Morgan. Watch video from Bears of the Last Frontier: City of Bears.

The scent that a female brown bear gives off helps the male determine if she is receptive to mating. Watch video from Bears of the Last Frontier: City of Bears.

It’s finally here — time for us to share our incredible Alaskan adventure with the world through Bears of the Last Frontier. It has been quite the journey. The film has been nearly two years in the making, and for both of us it has become an unforgettable part of our lives

Delayed implantation, hibernation, and everything else you'd want to know about Ursus arctos.

Fortress of the Bears filmmaker Shane Moore on some of the filming techniques he used during his shoot on Alaska's Admiralty Island. A behind-the-scenes look at what goes into the making of a nature documentary.

After a spring and summer with no sign of salmon, a mother bear is desperate to catch fish to feed her famished cub. Watch video.

Enter a world shaped by bears, trees, and salmon, and explores the delicate balance of their interconnected lives. Watch a preview of PBS Nature's Fortress of the Bears.