Grizzly (1976) on Netflix

An eighteen foot, two thousand pound Grizzly bear terrorizes campers and hikers at a state park. This frustrates the head Park Ranger and decides to hunt it down. His efforts however were thwarted by the Park Supervisor and many drunk hunters into the areas. After the bear kills another campers, two rangers, a hunter and a little boy and his mother, The ranger employs his friend, a Naturalist to find the bear and tranquilize it. But he gets killed. Finally with the help of a Helicopter Pilot the ranger goes in pursuit to finally kill it with any means necessary with rifles and a rocket launcher. It is to the end when they realize the bear is much stronger than they imagined.