A routine evening walk through Yellowstone National Park turned into a terrifying fight for survival when an elderly visitor was violently tossed into the air by an aggressive bison, leaving horrified campers scrambling to help as the massive animal continued charging through a crowded campground.

The frightening encounter unfolded Friday evening at Yellowstone’s Bridge Bay Campground, where an unnamed grandfather had been walking with his grandson when they unexpectedly crossed paths with an agitated bull bison during what witnesses described as an unusually aggressive rampage.

According to eyewitnesses, the enormous animal suddenly charged through a wooded area before striking the man with one of its horns, launching him several feet into the air in full view of dozens of stunned campers.

Photographer Mike MacLeod, who witnessed the entire incident and captured portions of it on camera, described the attack as unlike anything he had seen despite years of observing bison throughout the region.

“The bison hooked him with his left horn on his hip and tossed him in the air,” MacLeod recalled.

“He made a perfect flip and landed on his side.”

The experienced wildlife photographer estimated that the victim soared nearly eight feet above the ground before crashing down.

“The bison was at least six feet tall, and the victim was several feet above him,” he said.

Witnesses immediately rushed toward the injured man after the animal finally moved away, fearing the bison might return for another attack.

Despite suffering what appeared to be significant injuries, the grandfather reportedly remained conscious while bystanders worked together to protect him until emergency responders arrived.

“One guy held his hand,” MacLeod said.

“Another guy pulled security on the outside to make sure that bison didn’t come back.”

Others quickly assumed different roles as the emergency unfolded.

“A gal in a car was on the phone with 911, and another gal did a blood sweep, but we couldn’t find any blood,” he explained.

Although there were no obvious external wounds, witnesses said the victim complained of severe pain in his hips and the leg that absorbed the impact of the fall.

His grandson later told MacLeod that his grandfather had suffered “some pretty significant injuries” and remained far from being out of danger.

The grandson also reportedly worried that his grandfather may somehow have caused the confrontation.

However, MacLeod strongly disputed that suggestion after reviewing exactly how events unfolded.

“They were just out for an evening walk,” he said.

“They just happened to turn around the corner, and there’s a bison.”

According to the photographer, the grandfather and his grandson had done nothing to provoke the animal.

Instead, he believes the bull was already displaying unusually aggressive behavior before the pair ever encountered it.

“You can tell he was agitated, pissed off, and charging anything and everything,” MacLeod said.

“I’ve been around bison for a while, but this was really weird.”

The experienced photographer admitted he could not understand why the animal singled out the grandfather and his grandson.

“There were so many people around, and most of them were closer to and behind the bison,” he said.

“It was really weird.”

The attack was actually the culmination of a series of alarming encounters involving the same animal throughout the campground earlier that evening.

MacLeod had first noticed something was wrong after his wife spotted the large bull wandering slowly among campsites at Bridge Bay, located south of Fishing Bridge.

Recognizing the unusual opportunity to photograph wildlife, the former Army combat photographer retrieved his camera and began documenting the animal’s movements from what he believed was a safe distance.

Initially, the bull appeared calm.

But that changed rapidly.

“He was coming up to this group of kids, who were taking pictures on their cellphones from a good distance away,” MacLeod recalled.

“And then the buffalo charged these kids.”

Fortunately, the children managed to escape unharmed before the bull turned its attention elsewhere.

MacLeod immediately feared the animal had become dangerously unpredictable.

His concerns proved justified.

The bull continued moving aggressively throughout the campground, sending frightened visitors running while others shouted warnings to nearby families.

The frightening chaos eventually subsided when the bison settled into a patch of dirt alongside the roadway.

“He was sitting in the dust, like bison do, with his head out toward the road,” MacLeod explained.

At that point, the grandfather and his grandson unknowingly entered the area.

Witnesses said the pair appeared to follow all recommended wildlife safety guidelines.

Rather than approaching the animal, they reportedly remained approximately 100 yards away—the minimum distance recommended by the National Park Service for observing bison safely.

“I didn’t see anybody getting close,” MacLeod emphasized.

“People were yelling, ‘Careful, there’s a bison coming through,’ and they kept their distance.”

“They were very respectful.”

Like many other visitors, the pair briefly paused to take photographs before deciding to leave once the bull became more active.

Instead of remaining near the roadway, they attempted to avoid the animal by moving into a nearby wooded area.

Unfortunately, events took another unexpected turn.

According to MacLeod, a white pickup truck passing along the campground road suddenly attracted the bull’s attention.

“The bison was charging the truck,” he said.

“The guy in the truck saw that happening, and he just kept going.”

Once the truck continued driving, the frustrated animal redirected its aggression toward the wooded area where the grandfather and grandson had taken cover.

“The bison then went to where those two were hiding in the trees,” MacLeod said.

The grandson managed to escape before the bull focused entirely on his grandfather.

Witnesses watched helplessly as the animal pursued the older man through the trees before finally catching him.

The powerful bull lowered its head, caught the victim with one horn, and launched him violently into the air.

After crashing to the ground, the grandfather faced an even greater danger.

MacLeod said the bison remained standing over the injured man, shaking its head aggressively as if preparing for another strike.

“I was really afraid he was going to gore the guy on the ground,” he recalled.

Without hesitation, MacLeod stopped filming and ran directly toward the animal.

“I had to get the bison’s attention.”

“I yelled loud and was trying to be as big and intimidating as possible.”

Other campers quickly recognized what he was attempting and joined him.

Together, the group advanced toward the bull while shouting until the animal finally retreated from the campground.

Only then could everyone fully concentrate on helping the injured victim until Yellowstone emergency medical personnel arrived.

MacLeod later reflected that the encounter completely changed his understanding of how unpredictable bison can become during the summer breeding season.

The attack occurred during the annual bison rut, which generally lasts from June through September.

During this period, mature bulls become significantly more territorial and aggressive as they compete with rivals for access to females.

Wildlife experts have long warned that bulls can react unpredictably during the rut, even toward people who appear to be maintaining appropriate distances.

Still, MacLeod admitted the incident exceeded anything he had previously witnessed.

“It’s changed my idea of what to expect from these guys at this time of year,” he said.

“I would not have predicted that happening.”

As of now, the National Park Service has not publicly released additional information about the attack or the grandfather’s current medical condition.

The frightening encounter nevertheless serves as another reminder that even experienced visitors who appear to follow recommended safety guidelines can find themselves in danger when encountering one of Yellowstone’s most powerful—and unpredictable—wild animals during its most aggressive season.