A Colorado teenager was hospitalized after a bison charged at him during a visit to the Theodore Roosevelt National Park on Saturday.

The 17 year old was transported from the park by helicopter to a Bismarck, North Dakota, hospital after he was thrown about six feet into the air, according to the National Park Service. The bison struck the teen in the back and gored his right thigh.

A Roosevelt Teddy bear gifted to a teenager after he was hospitalized in a bison attack at the Theodore Roosevelt National Park.

The teenager, who did not wish to be identified, told NBC News Monday that he and a friend were about to go backpacking on a trail at the park when the attack happened.

"So I was hiking up the trail, got about a quarter of a mile and there was to my left, like the entire herd, and to my right there was one really big bison," he told NBC News. "And I give him enough space where I was walking around him. I was walking on the trail, and then all the sudden, I just kind of got this feeling that something was like chasing after me."

He started running as the bison charged at his back, slashed through his leg with its horn and and then threw him up and into the air.

"So luckily I fell onto my backpack, which saved my life, honestly," he said. "If I didn't have that, I would have a lot more injured."

After he landed a group of people rushed to his aid and called 911 as his friend began to administer first aid. The 17 year old said he had a panic attack after he landed, but his friend, who he was traveling with on a road trip, kept him calm.

"I was in such shock and adrenaline rush that I didn't realize (the bison) had torn that big of an injury in the back of my leg," he said. "And I looked back and there was just chunks of tissue. And I was like, 'oh boy.'"

The teenager insisted he kept a reasonable distance to the bison and that he did nothing to irritate the wild animal before the attack. He was walking the trail but wasn't able to go around the bison because of a cliff edge nearby.

"I could have given him a little bit more space, but I had been that close to a bison before on the trail," he said. "I didn't do anything to like aggravate him. It was like all by chance."

He is expected to be released Monday after doctors finish treating his his gash. The hospital sent a Teddy Roosevelt impersonator to his room and park officials gave him a stuffed teddy bear, toys which are named after the former president.

Saturday's attack occurred nearly a week after a 9-year-old girl was sent her flying into the air at Yellowstone National Park.

The girl was with group of people in the Old Faithful Geyser area of the park in Wyoming, standing within five to 10 feet of the bison before the animal charged.

The park service said in a statement that animals at at national parks are wild and that park regulations require visitors stay at least 25 yards from animals such as bison, elk, deer and horses.