It was July 1967. Steve Ashlock and John Cook were 14. They were at Glacier National Park in Montana. They were on a fishing trip. 

    Glacier was crowded. But Steve and John escaped the crowds. They hiked up to Trout Lake. This lake is surrounded by thick forests and rugged mountains.

    At the lake, the boys saw a group of bears. At least two were grizzlies. What luck! Grizzlies are among North America’s most powerful animals.

    Steve and John weren’t scared. They knew that grizzlies usually stayed away from humans. In Glacier’s 57-year history, there had never been a deadly grizzly bear attack.

    But that was about to change.

    And ideas about grizzlies—and how we treat them—would never be the same. 

    It was July 1967, and Steve Ashlock and John Cook were on a fishing trip in Montana at Glacier National Park. The 14-year-old boys had arrived the day before. 

    Glacier had been crowded all summer, but Steve and John quickly escaped the crowds. They hiked several miles up to Trout Lake, a beautiful lake surrounded by thick forests and rugged mountains.

    At the lake, the boys spotted a group of bears. At least two were grizzlies. What luck! Grizzlies are among North America’s most powerful animals.

    Steve and John weren’t frightened. They knew that grizzlies usually stayed away from humans. In Glacier’s 57-year history, there had never been a deadly grizzly bear attack.

    But that was about to change.

    And ideas about grizzlies—and how humans treat them—would never be the same. 

    Grizzlies have lived in North America for about 50,000 years. Tens of thousands of them once roamed the Western United States.

    In the 1800s, people began to build on land where the bears lived. Many grizzlies were chased from their habitats. At the same time, stories spread about these bears. Some stories made them seem like monsters that ate humans.

    So people started hunting grizzlies. By the time John and Steve were growing up, there were fewer than 1,000 grizzlies in the lower 48 states. The only truly safe places for a grizzly were in two national parks: Glacier and Yellowstone. In these parks, hunting was not allowed. All animals were protected by law.

    Grizzlies have lived in North America for about 50,000 years. Tens of thousands of them once roamed the Western United States.

    In the 1800s, people began to build on land where the bears lived. Many grizzlies were chased from their habitats. At the same time, stories spread about these bears. Some stories made them seem like monsters that ate humans.

    So people started hunting grizzlies. By the time John and Steve were growing up, fewer than 1,000 grizzlies remained in the lower 48 states. The only truly safe places for a grizzly were in two national parks: Glacier and Yellowstone. In these parks, hunting wasn’t allowed and all animals were protected by law.

    By the mid-1900s, experts knew more about grizzlies. Grizzlies are not monsters. They are smart and shy.

    Grizzlies do have fearsome powers. Their claws can tear apart tree stumps. Their jaws can chomp through bone. But they rarely attack humans. Normally, they only attack if they sense they are in danger.

    So John and Steve weren’t scared when they saw the grizzlies. They felt lucky. They got to see these amazing creatures in the wild.

    But what happened the next evening did scare them. The boys were out on Trout Lake. They heard a strange sound. They looked over at their campsite. A grizzly was eating their food!

    The boys shouted at the bear. They hoped to scare it away. That didn’t work. So they snuck to shore, put on their boots, and ran. They prayed the grizzly wouldn’t chase them.

    The boys hiked to a ranger station. They told their story to a ranger.

    The next morning, they went back to their campsite. The bear was gone. But it had torn apart their tent. They were lucky to have gotten out alive.

    By the mid-1900s, scientists had learned more about grizzlies. They understood that, far from being monsters, these bears are intelligent and shy.

    Grizzlies do have fearsome powers—their sharp claws can tear apart tree stumps, and their jaws can chomp through bone—but it’s unusual for grizzlies to attack humans. Normally, they only attack if they sense they are in danger.

    For this reason, rather than being afraid when they spotted the grizzly bears, John and Steve simply felt fortunate to have the chance to see one of Earth’s most amazing creatures in the wild.

    But what happened the following evening filled them with terror. The boys were out on Trout Lake when they heard a strange sound. They looked over at their campsite and saw a skinny grizzly eating their food!

    The boys shouted at the bear, hoping to scare it off. When that didn’t work, they snuck to shore, threw on their boots, and ran. They prayed the grizzly wouldn’t chase after them.

    Steve and John hiked 4 miles through the darkness. They made it to a ranger station and told their story to the ranger on duty.

    The next morning, when they returned to their campsite, the bear was gone. But it had torn apart their tent. They were lucky to have gotten out alive.

    There was something John and Steve didn’t know. Glacier was having a grizzly crisis. Some grizzlies had lost their natural fear of humans. They were behaving aggressively. But the real problem wasn’t the bears.

    It was people.

    People kept leaving trash at the park. There was a lot of litter. Some people were even using trash to bring grizzlies closer to them.

    This was happening every night at one of the park’s hotels. Workers would dump leftover food into an outdoor pit. Guests liked to watch the bears fight over hot dogs and chili.

    Feeding human food to a wild animal is unhealthy for the animal. It can also change the way the animal acts in the wild.

    In Glacier, some grizzlies got used to eating trash. They lost their fear of humans. Then they moved into busier parts of the park. 

    What John and Steve didn’t know was that Glacier was in the middle of a grizzly crisis. Some grizzlies had lost their natural fear of humans and were behaving aggressively. But the real problem wasn’t the bears.

    It was people.

    More specifically, it was the garbage people left behind. Glacier was filled with litter. Some people were even using garbage to bring grizzlies closer to them.

    This was happening every night at one of the park’s hotels. Workers would dump leftover food into an outdoor pit, and guests would applaud as they watched grizzlies fight over hot dogs and chili.

    Feeding human food to a wild animal is unhealthy for the animal. It can also change the way the animal behaves in the wild.

    In Glacier, some grizzlies started to depend on garbage for survival. They lost their natural shyness toward humans. Then they moved into busier areas of the park. 

    On August 13, the world woke up to shocking news from Glacier. Two 19-year-old women had been killed by two different grizzly bears. This was just one month after John and Steve’s scary night at the park.

    The bears attacked the women as they slept in their tents. Neither grizzly had been surprised or frightened into attacking.

    How could this have happened? Glacier’s leaders were forced to face the truth. The garbage in the park had turned the grizzlies into killers. 

    For years, rangers and park leaders had known trash was a problem. All summer they had been getting complaints about aggressive grizzlies. Yet no action was taken. 

    On August 13, there was shocking news from Glacier. Two young women had been killed by two different grizzly bears. This was just one month after the bear tore up John and Steve’s tent.

    The women had been asleep in their tents. The bears had not attacked out of surprise or fear.

    The trash in the park had turned the grizzlies into killers.

    Rangers and park leaders knew trash was a problem. All summer they had been getting complaints about aggressive grizzlies. Yet no action was taken. 

    On August 13, only a month after John and Steve’s frightening experience at the park, the world woke up to shocking news from Glacier. Two 19-year-old women had been killed by two different grizzly bears.

    The bears attacked the women as they slept in their tents. Neither grizzly had been surprised or frightened into attacking.

    How could this have happened? Glacier’s leaders were forced to face the truth: that the garbage in the park had turned the grizzlies into killers.

    Rangers and park leaders had known for years that trash was a problem, and they had been getting complaints all summer about aggressive grizzlies. Yet no action had been taken. 

    That night in August became known as “the night of the grizzlies.” And it brought about a big change in America’s national parks. 

    Rangers cleaned up the trails. Parks switched to bear-proof trash cans. At campgrounds, picnic areas were set up far away from where people slept. If a grizzly was seen near a trail, the trail would be closed. 

    Those new rules led to lasting change. Today Glacier is a cleaner and healthier place for its 300 grizzlies—and for humans. 

    That night in August became known as “the night of the grizzlies.” It led to changes in America’s national parks.

    Rangers cleaned up the trails. Parks switched to bear-proof trash cans. At campgrounds, picnic areas were set up far from where people slept. If a grizzly was seen near a trail, the trail would be closed.

    The new rules led to lasting change. Today Glacier is a cleaner and healthier place for its 300 grizzlies. It’s safer for humans too. 

    That night in August, which became known as “the night of the grizzlies,” brought about a big change in America’s national parks.

    Rangers cleaned up the trails, and parks switched to bear-proof trash cans. At campgrounds, picnic areas were set up far away from where people slept. If a grizzly was seen near a trail, the trail would be closed.

    Those new rules led to lasting change. Today Glacier is a cleaner and healthier place for its 300 grizzlies—and for rangers and visitors too.