In some situations, like at Katmai National Park and Preserve, natural food sources are so plentiful and predictable that people can go to where bears feed to view bears at close distances. Viewing platforms are used to make people's behavior predictable to bears, and visitors must follow strict rules of behavior. This is truly a unique experience that is not typical of parks in the lower 48 states. If you can't make it to Alaska, you can watch brown bears and other wildlife in Katmai through wildlife webcams.
In most parks, in addition to adapting to natural events, bears adapt to and learn from their interactions with people and developed areas. Seeing a bear in the wild can be an exciting event; park managers strive to ensure that visitors experience bears behaving as naturally as possible and in situations that are safe for people and safe for bears. Managing interactions between people and bears involves managing not only bear behavior, but also human behavior! Yosemite National Park has a long history of developing new ways to address changes in human-wildlife interactions. Learn more by watching the Yosemite Nature Notes 26: Black Bears video.
On the bear side of the equation, managers strive to prevent bears from learning to associate people and human spaces with food by providing bear-resistant food storage and garbage receptacles and enforcing their use. Bears are very adaptable and are attracted to many of the same foods that humans enjoy. For bears that have not yet learned to associate people with food but have started to enter developed areas, managers may use techniques called aversive conditioning to teach bears that human spaces are unpleasant. This can include noisemakers, shooting them with beanbags, or capturing and releasing them.
Once a bear learns that campgrounds, picnic areas, and people are an easy source of food, however, managers can do very little to change that bear's behavior. When seeking food, the bear may even start to interact aggressively with people, increasing risks for both bears and people (for more information, see Storing Food).
When preventive methods are not sufficient to protect park visitors and staff from aggressive bears, there may be no alternative but to remove the bear. This is always a very difficult decision for park officials. Sequoia & Kings Canyon National Parks and Katmai National Park and Preserve both offer vivid stories of the series of events that can lead to the end of a bear's life (see the full story of bear #583 in Sequoia & Kings Canyon and the story of the last bear killed at Brooks Camp in Katmai). In both cases, the parks studied the series of events to determine how to avoid similar outcomes in the future. Katmai staff implemented measures that have led to a remarkable safety record at Brooks Camp despite increased numbers of visitors and bears. The staff at Sequoia & Kings Canyon implemented a Human-Bear Management Program that uses food storage techniques, education, and aversive conditioning of bears to facilitate safety in areas that humans and bears enjoy.
This is why your actions in parks are so important. Using appropriate receptacles to store your food and disposing of garbage properly can help ensure that bears don't accidentally become conditioned to human food. You help keep bears wild by practicing proper viewing etiquette, keeping your distance from bears, and doing your best not to disturb them.