Enter a world shaped by bears, trees, and salmon. Watch the full episode of PBS Nature's Fortress of the Bears.

Admiralty Island, part of the Tongass National Forest, hosts the largest concentration of brown bears in the world. Watch video.

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.

It's taken all spring and summer, but salmon finally return to Admiralty Island to spawn. Watch video.

This film investigates the parallel stories of collapsing Pacific salmon populations and how biologists and engineers have become instruments in audacious experiments to replicate every stage of the fish’s life cycle.

An interview with Salmon: Running the Gauntlet filmmaker Jim Norton.

Here is a brief look at the lifecycle of one of the world’s most popular and most important fish.

A Montana Public Radio interview with writer David James Duncan, who was featured in Salmon: Running the Gauntlet.

Facts and stats about the members of the Salmonidae family.

NATURE goes beyond the ongoing debate over how to save an endangered species to expose a wildly creative, hopelessly complex and stunningly expensive approach to managing salmon.