The grandfather who went wildly viral after he was filmed being tossed in the air by a bison at Yellowstone National Park reassured everyone he is “OK” — despite undergoing surgery for a broken thigh bone.

Carl Isom-McDaniel, 65, was thrown around eight feet in the air by the huge wild animal Friday night while visiting the park with his 13-year-old grandson.

He broke his femur — the strongest bone in the body — in four places near his hip, but was already able to stand Monday after having surgery the day before, he told CNN.

“Thank you everyone I am OK,” McDaniel posted to his Facebook account late Sunday with a thumbs-up emoji.

The retiree and community leader from Kendall, Wash. also praised the animal for not killing him during the attack.

“When I was on the ground immobile, unable to move, he was right on top of me,” McDaniel told CNN.

“He could have stomped on me, he could have gored me, he could have done almost anything to take my life, and he did not do so.”

Mike MacLeod, the professional photographer who captured the now-insanely viral video, said McDaniel was “in good spirits” as soon as the danger was over — and mostly worried that people would think he had upset the wild animal.

“He was in a lot of pain, but was conscious and joking the whole time,” the shutterbug told Cowboy State Daily.

“He was really worried and wanted to see the video to make sure that it wasn’t his fault.

“It’s not his fault. You can tell from the very beginning. That was a really, really angry bison.”

Before the terrifying attack, the bison — likely hopped up on testosterone at the start of mating season — had already menaced several groups of visitors.

They included a group of teenage boys who quickly scattered when the bison charged, the photographer said.

After scaring off the teens, the bison took a moment to rest in the dirt near a picnic table just off a campground road that was still covered in dinner leftovers.

It was at that moment McDaniel and his grandson stopped their pickup truck to take pictures of the bison, unaware he was in an irritated state.

“The bison stopped rolling in the dust and kind of sat up. He’s looking in the direction of those two,” MacLeod said.

“And as soon as they stop taking pictures, the bison stands up and the grandfather’s like, ‘Let’s get out of here. I don’t like this.’”

Another pickup truck drove by at that moment, which appeared to briefly capture the attention of the bison.

However, once the vehicle was out of sight the massive creature turned his attention to McDaniel and his grandson, chasing them around a copse of pine trees.

The grandson was able to escape using some fancy footwork, but McDaniel was a sitting duck as the bison charged at him, hooking him with his left horn near his hip before flipping him into the air.

MacLeod, who was watching in horror from a distance, said he could tell the bison was “really, really angry” by his body language — his head rearing up and down in an aggressive manner.

The photog added that he was so afraid that the bison was going to gore McDaniel on the ground that he stopped filming, ran at the animal while yelling and was “trying to be as big and intimidating as possible”.

Several other bystanders followed suit, causing the bison to run off.

Fellow tourists stayed by McDaniel’s side while they waited for a park ambulance to transport him to a hospital for treatment, which arrived about 10 minutes later.

Park regulations require visitors to keep their distance from bison — giving them at least 75 feet of breathing room, particularly during mating season, which coincides with the height of Yellowstone’s tourist season.

MacLeod stressed that every visitor he observed in the park Friday, including McDaniel and his grandson, were keeping a “respectful distance” from the animal, and had done nothing to provoke it to charge.