Bears are congregating in Brooks Falls, Alaska, as they attempt to fatten themselves up as much as possible before winter hibernation begins. Katmai National Park and Preserve ranger Troy Hunt explains why the burly mammals head to this river to eat as many fish as they can bear.

Bears are congregating in Brooks Falls, Alaska, as they attempt to fatten themselves up as much as possible before winter hibernation begins. Katmai National Park and Preserve ranger Troy Hunt explains why the burly mammals head to this river to eat as many fish as they can bear.