PHOENIX (AP) — An Arizona woman who suffered fractured vertebrae and collapsed lungs after being gored by a bison in Yellowstone National Park has said “yes” to her boyfriend’s hospital proposal.

Chris Whitehill said he planned to propose to Amber Harris during their vacation in the park this week, but after spending just one night there, an encounter with a bison upended those plans.

The couple from the Phoenix area had walked to a lodge for some coffee Monday and decided to walk through a field to Yellowstone Lake in Wyoming, Harris posted on Facebook the next day.

They waited for some people and about 20 elk to leave the area before continuing. They also noticed two bison. They watched one “drop and roll in the dirt, like a dog would,” she wrote. “He got up on his feet and started walking, then running toward us.”

The bison “struck her head-on and she was airborne,” Whitehill told KPNX-TV in Phoenix. “I think she did one or two backflips in the air, and I was screaming and yelling trying to distract him. She landed pretty hard on her back.”

Harris, 47, was airlifted to Eastern Idaho Regional Medical Center in Idaho Falls, Idaho, where she recovering from seven fractured vertebrae, collapsed lungs and bruising.

Whitehill “got down on one knee beside my hospital bed,” Monday night, Harris wrote in a Facebook post that included a photo of the ring on her finger. “Without any hesitation I said yes!”

Whitehill started a GoFundMe campaign for Harris’ medical bills. In an update posted Thursday, he said Harris does not need surgery but does have to wear a back brace to keep her spine immobilized.

The bison attack was the first in Yellowstone in just over a year, park officials said.