It was a fun time at the lake — until the otter arrived.

After spending about an hour swimming with friends in Bone Lake near Luck, Wis., on Saturday, Rory Kliewer began to climb a ladder onto a dock when she suddenly felt something bite her backside and thigh.

“I thought it was a northern pike,” the 12-year-old Minneapolis girl said Wednesday. “I thought a fish was after me.”

As she threw the creature off of her, she realized that the animal was an otter — later estimated at 3 1/2 feet long and about 40 pounds.

“It was a big, nasty one,” said Rory, who had been staying at a friend’s family cabin over the weekend.

The otter then bit Rory’s head and pulled itself onto her, scratching her face. Rory managed to climb the ladder onto the dock and then throw the otter off her once again, screaming throughout the incident, she said.

But the otter didn’t stop there.

It jumped onto the dock, and Rory ran onto land with the otter in pursuit, she said. A dog and her friend’s mother tried to scare the animal away, but it rose up on its hind legs and hissed. The otter didn’t retreat until Pat Hinschberger, the cabin’s owner and Rory’s friend’s father, rushed to the scene and yelled at the animal.

“As far as I’m concerned, this thing was literally trying to kill this kid,” Hinschberger said. He added that the incident lasted no more than a minute, but it felt like much longer.

Rory was taken to a local emergency room, where doctors told her it was their first time treating a victim of an otter attack, she said. Speaking from her home Wednesday, Rory was still recovering from bite wounds, scratches and bruises, and possibly the most significant injury: the trauma of the experience, which she called “really frightening.”

“I’m pretty traumatized,” she said. “It’s better than it was Saturday or Sunday, but I’m still pretty shaky.”

Rory said she hasn’t wanted to be alone or have her arms or legs out of view since the incident, and she’s keeping her dog close for comfort.

“I worry that something’s sneaking up,” said Rory, who is getting rabies shots as a precautionary measure.

And any more swimming is out of the question for the time being.

“I’m pretty positive I’ll get back to swimming in pools, but I don’t ever know if I’ll ever get back to swimming in lakes,” Rory said. “(But) I hope I will.”

She added that she was lucky to have been wearing a life jacket and goggles at the time of the attack — the life jacket probably saved her from drowning and the goggles probably saved her eyes from injury, she said.

“It definitely could have been worse,” Rory said.

Hinschberger, who lives in Minneapolis and has been coming to Bone Lake all his life, said this was the first time he’s heard of anyone being attacked by an otter at the lake. But after the attack, he did hear of a couple of incidents occurring in the past few weeks in which otters behaved threateningly toward dogs, he said.

“Nobody I have at our cabin is going in the water until those otters are gone — that’s the way I look at it,” Hinschberger said. “I can’t chance something like that happening again.”

It’s not clear if the Wisconsin Department of Natural Resources is doing anything in response to the attack; calls to the department were not immediately returned Wednesday. Hinschberger, however, said he does plan to try to trap the animals.

The question of why the otter attacked Rory, who said she and her friends had not seen any otters in the water before the incident, remains unanswered. Hinschberger, whose daughter attends school with Rory, said he’s not a wildlife expert but believes it could have been a mother otter trying to protect her young.

And while it was a scary experience for everyone involved, Hinschberger praised Rory for the strength she displayed.

“Rory is the toughest … kid I’ve ever met,” he said.

Andy Rathbun can be reached at 651-228-2121. Follow him at twitter.com/andyrathbun.