Grizzly bears are very dangerous large predators, but actual attacks on people are rare, and the risk can be greatly reduced with the right behavior in bear country.

How dangerous they are

• An adult grizzly can weigh several hundred kilograms, run around 30–35 mph, and has a bite force measured at over 1,000 psi, strong enough to crush very hard objects.

• Their claws and strength allow them to inflict severe or fatal injuries in seconds if they attack.

How often they attack

• In North America, fatal grizzly attacks are uncommon compared with how many people visit bear country; for example, in Yellowstone there have been only eight grizzly-caused deaths since the park was founded, across over 200 million visits.

• Statistically, the chance of being killed by a grizzly in places like Yellowstone is often cited as lower than dying in an avalanche or from lightning, showing that while encounters can be serious, they are not frequent.

When they are most dangerous

• Grizzlies are especially dangerous when surprised at close range, when defending cubs, or when protecting a carcass or food source.

• They can be more aggressive than black bears, which are more likely to flee; grizzlies are more inclined to stand their ground or charge if they feel threatened.

How to reduce the risk

• Make noise while hiking (talk, clap, use bear bells), travel in groups, and avoid hiking at dawn, dusk, or at night when bears are more active.

• Keep a clean campsite, store food and scented items properly, carry bear spray where recommended, and never approach a bear or its cubs for photos or closer viewing.

What to do in an encounter

• If you spot a grizzly at a distance, stay calm, speak in a calm voice, back away slowly, and give it plenty of space rather than running, which can trigger a chase.

• If a grizzly makes a defensive charge (for example, you surprised it or it is defending cubs), outdoor safety guidelines often advise using bear spray and, if contact is imminent in a clearly defensive attack, lying face down, protecting your neck, and playing dead until the bear leaves.