Grizzly Man chronicles the life and death of Tim Treadwell, a self-appointed grizzly expert who spent 13 summers camping in Alaska, where he lived among the bears, while videotaping much of what he saw. In 2003, Treadwell and his girlfriend were killed by a grizzly, which was later euthanized by park rangers. Herzog's film primarily consists of Treadwell's footage, an oddball sort of Wild Kingdom. As a nature photographer, Treadwell managed to capture some pretty amazing stuff, much of which featured himself as a sort-of host. If you can imagine a cross between Mr. Rogers and Richard Simmons doing an impression of Marlin Perkins, you begin to get an idea of Treadwell's manic personality. As Herzog shares more footage of Treadwell interacting with bears and foxes or just playing to the camera, it becomes clear the guy was about four or five cans short of six-pack.

Grizzly Man is pretty convincing, but several things cast doubts. Some of the people Herzog interviews come across more like actors than real people. Then there are the things like the fact that Treadwell, for someone who spent months at a time camping in the wilds of Alaska, always looks clean and well-groomed. And how did he manage to keep charging the batteries that run the video camera when there was no electricity?

The problem with Grizzly Man is that it comes along at a time when our perception of reality has been so warped by "reality television" that we no longer have a sense of what is real. You want to believe in its authenticity, but you don't want to be duped. It plays out like American Movie, which was difficult for many people to accept as reality, and This Is Spinal Tap which, at the time, had many people convinced it was about a real band.

So the question with Grizzly Man remains: Is this fact or fiction, real or fake? Ultimately, the answer doesn't matter. If the film is fake, it is brilliant in its execution. If it is real-which it probably is-then it's no less profound or engaging. And either way, Grizzly Man is entertaining.